Accessorizing Boston Volume 1 by Northeastern School of Architecture

ACCESSORIZING BOSTON V.1

The Architect’s, Planner’s, and Policy Maker’s Guide to Implementing Accessory Dwelling Units in Boston

This publication has been prepared as a part of the 2015 Masterâ&#x20AC;&#x2122;s Research Studio in the Northeastern School of Architecture. All research and content in this publication was produced by the Accessory Dwelling Units research team. Published by Northeastern University School of Architecture 360 Huntington Avenue Boston, Massachusetts 02215 Copyright 2015 by Northeastern University School of Architecture All rights reserved

accessory dwelling units

INTRODUCTION -Acknowledgements and Credits -History -Case Studies -National and Global Perceptions of the Backyard -Psychology of NIMBYism CITYWIDE OPPORTUNITY MAPPING + ANALYSIS -Market Potential -Boston Zoning -Neighborhoods NEIGHBORHOOD SCALE ANALYSIS -Jamaica Plain -Hyde Park -West Roxbury -East Boston -Dorchester -Commercial Districts BUILDING SCALE ANALYSIS -Typologies -Building Organization -Regulatory Thresholds -Typological Examples -Structure -Design Opportunities CONSTRUCTION DETERMINANTS -Foundations -Framing -Utilities SOURCES APPENDIX

introduction / credits and acknowledgements

THE RESEARCH STUDIO

Kelly Bacon, Kristen Barrow, Whitney Chicoine, Matthew Cox Steven DuRoss, Nick Guertin, Sophia Hastings, Kelsey Laser Sean Sims, Leah Solomon, Thomas Swanson, Peter Travis

accessory dwelling units

Acknowledgements The studio team would like to thank the following for their valuable contributions to this body of research: William Christopher - Commissioner, City of Boston Inspectional Services Department Rob Consalvo - Deputy Director, City of Boston Home Center Sheila Dillon - Chief of Housing and Director, Department of Neighborhood Development Robert Gehret, Jr. - Deputy Director, Policy Development and Research Division, Department of Neighborhood Development Brian Glascock - Senior Advisor for Zoning Reform, Boston Redevelopment Authority Addison Godine - North Star Management Matthew Littell - Faculty, Northeastern University School of Architecture Diane Marchioni - City of Boston Susan Nguyen - Program Manager, Housing Innovation Lab, Mayorâ&#x20AC;&#x2122;s Office of New Urban Mechanics Marcy Ostberg - iTeam Program Manager, Mayorâ&#x20AC;&#x2122;s Office of New Urban Mechanics Devin Quirk - Director of Operations, Department of Neighborhood Development Andrew Theokas - Digital Cartographer, City of Boston Peter Wiederspahn - Interim Director, Northeastern University School of Architecture

introduction/research scope

A NEW TYPOLOGY FOR BOSTON

Like many growing metropolitan areas across the country, Boston’s rapid population expansion has put considerable strain on the city’s existing housing stock. Availability of affordable options for many residents continues to shrink as both rents and home sales surge. This Graduate Research Studio has been organized to explore and analyze alternative strategies to increase residential development capacity in Boston through the use of Accessory Dwelling Units (ADU’s).

Accesory dwelling units are an interesting avenue for increasing housing stock in a densely developed and historical fabric like that of Boston. In many ways, ADUs offer a host of benefits that can be less characteristic of larger scale development. These benefits are appealing to a variety of stakeholders, and can be part of an effective strategy that balances the need for housing expansion while preserving the character of existing communities:

In 2010, the zoning code of Portland, Oregon was revised to incentivize Accessory Dwelling Units as a way to deal with that city’s housing affordability crisis. Rather than focusing heavily on high-rise construction as a way to increase the housing supply, city planners in Portland wanted to encourage the conversion of garages and construction of small (up to 800 SF) houses in the backyards of existing single family homes. Besides Portland- cities such as Seattle, Vancouver, Boulder, San Francisco, Austin, Nashville, and Philadelphia currently have similar ADU policies in place. The question for this research studio is whether certain neighborhoods in the Boston metro area would be suitable for a similar program, both because of existing urban patterns and the real estate market.

Light Impact, Smart Growth ADUs can be dispersed over generally large portions of neighborhoods, minimizing localized impact. Additionally, they can often be integrated as part of existing infrastructure rather than necessitating the use of new resources or municipal services. Socioeconomic and Demographic Factors These dwellings not only add more housing options for all residents, but are especially advantageous for specific populations. ADUs can allow senior citizens to age in place and continue their inclusion in a community. With Boston’s considerably large student population, ADUs offer another means to address concerns of overcrowding and community quality of life in the neighborhoods near college campuses.

accessory dwelling units

Ease of Development Review Because they add a relatively low amount of additional square footage, ADUs do not require the same intensity of development review required by larger counterparts. Shifting Views on Residential Needs Additionally, ADUs are appealing in a contemporary environment that increasingly emphasizes a cultural minimalism. This lifestyle stresses living lightly and making less demands of buildable urban land. ADUs offer excellent opportunities to become part of Boston’s future growth and development. Led by the Mayor’s office, the city has begun championing a comprehensive modernization of planning and zoning policies, in addition to setting a bold quota of new housing units to be created by 2030. Now is an ideal time to consider integrating ADUs as an important component of these municipal strategies and initiatives.

This semester’s research is broken down in various chapters that follow this introduction, including: -Case studies and data from various municipalities, especially those that most closely parallel Boston. Subsidies, zoning policies, and various other regulations are of particular note. -An examination of Boston’s built environment at three scales- studying the city-wide, neighborhood, and individual building level. -A thorough examination of construction strategies and limitations, defining what can be accomplished when building ADUs in such dense environments. Taken as a whole, this analysis offers a comprehensive set of tools for designers, developers, and municipal policy makers to evaluate ADU development strategies.

introduction / history & current practices

HISTORY OF ACCESSORY DWELLING UNITS Accessory Dwelling Units, informally known as granny flats, alley housing, or mother-in-law suites, have their historical roots in 17th century England. The dowager house is one of the first implementations of the granny flat. Typically used by the English royal family, the dowager house was a smaller, although still quite large, house that a widowed mother-of-the-heir would move into. This allowed for the heir to settle into the primary house and for the mother to stay comfortably close to the rest of the family. As areas became more dense, this became known as the granny flat. In more recent history, accessory dwelling units were a very common part of urban life beginning around 1900. Not only was living with multiple families in one building typical, but it was also common for singlefamily homes to have a smaller and detached secondary unit. After World War II, however, this all began to change. Rapid suburban and highway construction, automobile dependence, and emphasis on the nuclear family created endless blocks of nothing but singlefamily homes. Many suburbs instituted Euclideantype zoning which strictly adhered to one-use-only zoning, while developer tactics and residentsâ&#x20AC;&#x2122; desire for homogeneity divided entire neighborhoods by income and home prices. By the 1960â&#x20AC;&#x2122;s, most towns had outlawed any form of accessory dwelling unit. Despite being illegal, many places continued to built ADUâ&#x20AC;&#x2122;s. This usually happened in cities, where regulations were not as high as their suburban 8

1874 drawing of Clarence House, royal dower house in London

Boston alley, February 1909

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counterpart. San Francisco, for example, built about 10,000 ADU’s between 1950 and 1960. This typically occurred in cities experiencing a sudden economic boom. Although it had already been declared illegal, the term accessory dwelling unit did not appear in zoning code until the late 1970’s. It was at this time that cities and suburbs began to call for less automobile dependence,

more affordable housing options, and mixed-use communities. Municipalities began to discuss the possibilities of implementing ADU’s, and by the early 1980’s, a handful of municipalities decided to make them legal again. Aside from the benefits of creating new ADU’s, many municipalities considered legalizing ADU’s as a way to bring existing ADU’s into the legal realm. By doing this, the municipality is able to better regulate and tax these units.

Boston alley in East Boston, 19 December 1930

Boston alley in the North End, 17 December 1930

introduction / political + cultural contexts

POLITICAL + CULTURAL CONTEXTS Zoning code is not developed in isolation; the attitudes of the communities in which they exist shape the regulations that govern the neighborhoods across Boston. This section examines the political and cultural contexts that inform and impact the opportunity for accessory dwelling units. The first sub-section focuses on the importance of the yard, specifically the back yard. There is a taxonomy that identifies and evaluates yard properties based on how accommodating to ADUs specific yard typologies can be. The next section analyzes backyards in American media and culture in an attempt to understand how deeply the backyard is rooted in American society. We will also examine perceptions of the backyard, shared space, and the public realm in both the United States and worldwide. This section will study both old and new housing typologies that challenge the typical single-family home that has become so prevalent in American society. Additionally this section acknowledges the general movement in the United States towards more sustainable and mixed-use communities, and how accessory dwelling units can capitalize on this new way of thinking. Finally, there is an analysis of the â&#x20AC;&#x153;Not In My Back Yardâ&#x20AC;? movement, or NIMBYism, and how it can be detrimental to innovations in development within conservative communities. It is our hope that by understanding the motives and needs of NIMBYs, it will be easier to promote accessory dwelling units in a sensitive and effective way. 10

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introduction / political + cultural contexts

YARD TAXONOMY Yards, particularly back yards can be organized in numerous ways to create a range of experiences. The type of yard on a given lot is dependent on the environment that the homeâ&#x20AC;&#x2122;s owner and occupants wish to cultivate. There are residential properties in Boston that span this entire spectrum, ranging from the sprawling lawns and gardens of West Roxbury to the narrow paved spaces behind South End row houses. They are used for everything from playgrounds to parking spots. There are both quantitative and qualitative aspects that foster these varying experiential conditions of the yard. In this section, different yard types are identified and typologized according to a series of characteristics. The qualities assessed include both physical properties and uses. Some yard types are more conducive to the construction of accessory dwelling units than others. Conditions such as orientation, boundary consistency, surface materiality, and desired use all impact the feasibility of an ADU installation on a particular parcel. It is not only free-standing ADUs that are impacted by back yard conditions; a converted or attached units will interact either the side or rear yards as they will typically require an alternate entrance.

Photo: Backyard renovation project in East Boston with accessory structure. Architect: Lyle Bradley, 2015

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ORIENTATION

Front

Side

Rear

Front yards face the public street and are highly exposed. Typically the front yard is an inappropriate location for an ADU, as many neighborhoods desire to maintain a single-dwelling aesthetic on private properties. They are also generally much smaller than rear yards. Because they border directly on the sidewalk and street, there is very little privacy afforded to the front yard. Generally, no more than a perforated fence separates the front yard from public realm.

Side yards are the long, narrow areas that run alongside the building. They are generally unpleasant to occupy an only function as a means of connection between the front and rear yards. They are semi-private, in that only the occupants of the structure and their immediate neighbors can see into the side yard. Although they are less conducive to a new independent structure ADU, they can function as a means of egress to the main entrance of an interior conversion.

Rear yards are located behind the primary structure, concealed from the street. They are the most private and most flexible of all of the yard types in terms of dimensions, appearance, and use. It is the most appropriate place for an ADU constructed on the exterior of the primary structure. Under current zoning requirements, Section 20-2, accessory buildings are only permitted in rear yards as long as they are less than 15' high and 4' from the side lot line. 13

introduction / political + cultural contexts

BOUNDARY

Public

Open

Fenced

For the purpose of this taxonomy, public park spaces are included as a type of yard. Public parks can function in much of the same ways that private yards do, only with an increased sense of community. A homeowner and their neighbors might be more comfortable sacrificing some area and privacy in their own backyards for an ADU if there is an easily accessible, high quality public outdoor space nearby for their use.

Open yards possess no strict barrier to separate parcels from their neighbors, although there may be vegetation such as trees or flower beds to imply a separation between adjacent properties. This type of yard promotes a strong sense of community. Although it may be physically easier to construct an ADU on a lot with this type of edge condition, neighbors may be less inclined to support it because the ADUâ&#x20AC;&#x2122;s front door may have direct access to their yards.

Some yards are bounded by physical fences. These fences can be wood, metal, or masonry and range from high-end to low-end. People with fenced in yards tend to highly value privacy. They can also be used for protection; to keep pets or children from venturing outside of the property. Installing a physical barrier around a yard clearly demarcates ownership and promotes isolation. Neighbors may be more receptive to an ADU build in this type of yard because there is more privacy.

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MATERIALITY

Grass

Paved

Deck

Yards that are primarily green space are the most flexible, both in terms of uses and ADU construction. They are typically grass, although portions can be mulched and planted. This type of yard is generally the most pleasant to occupy, as it is comfortable and can be used for everything from cookouts to volleyball games. This yard type is most common in the periphery neighborhoods of Boston such as West Roxbury, Hyde Park, and Roslindale.

Paved back yards are generally inflexible and unpleasant to occupy. Generally, they are only intended to provide parking for the residents of the home. This condition is typically found in the more centrally located urban neighborhoods, such as the South End, Roxbury, and Beacon Hill. Although construction of ADUs is physically more difficult, neighbors may be more likely to approve of them on yards with these conditions because they are already aesthetically displeasing.

Decks or porches are exterior built structures designed specifically for human occupancy. They be large or small but are typically limited for occupancy and use due to safety concerns. According to Bostonâ&#x20AC;&#x2122;s housing code, it is illegal to fully enclose a deck and rent it as livable space. Therefore, to construct an ADU in a property with a deck, the existing structure would need to be demolished and the livable space would need to be constructed from the ground up. 15

introduction / political + cultural contexts

USAGE

Active

Passive

None

Many people enjoy utilizing their backyards for social activities. Often these active uses will require physical components installed in the yard, which can range in scale from a grill to a jungle gym. Residents with active-use back yards are likely to have a strong attachment to maintaining the open and inhabitable qualities of their yard. Therefore yards of this type are less conducive to new ADU construction; an interior conversion is likely a more suitable option.

Passive-use yards service the occupants of the primary residence, but are not generally inhabited by those individuals. These yard types are typically utilized as vehicular parking spaces or storage for trash cans. Side yards tend to serve these uses more commonly than rear yards do. There is some potential for an independent structure ADU development in these yard types, but it would need to account for and accommodate the parking space or storage that it displaces.

Some yards go unused by the buildingsâ&#x20AC;&#x2122; occupants and are neglected by owners. They become overgrown with weeds and can accumulate garbage and other refuse such as old furniture. A new ADU as an independent structure is most feasible in yards with these characteristics as they can improve the aesthetic quality of parcel. However, owners who are negligent in caring for yards may not suitably maintain the rental unit either.

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YARD USAGE ANALYSIS This plot chart shows the relative flexibility and ADU compatibility of some typical backyard uses. Flexibility, along the X-axis, refers to the relative permanence and involvement of the physical structures required to accommodate the various uses. Compatibility, along the Y-axis, refers to the ability of a back yard to continue to serve both the given use and a newly constructed ADU.

COMPATIBILITY

The uses identified are: pool and hot tub, swing set and playground, sports/games, gardening, pet accommodations, vehicle parking, social gathering, grilling, and trash receptacle storage.

FLEXIBILITY

introduction / political + cultural contexts

YARDS IN THE MEDIA

Yards carry a significant amount of importance in American culture. This section examines why back yards have become such an important idea to homeowners, as well as the relationship between the anticipation of rear yard occupancy compared to the reality of tyical use patterns.

REALITY TV

In the U.S., a cruicial aspect of the â&#x20AC;&#x153;American Dreamâ&#x20AC;? is homeownership with a white picket fence around the yard. This imagery is pervasive and its importance is perpetuated through the portrayal of back yards in the media, such as on sit-coms and HGTV. This sub-section identifies three aspects of yards as seen on T.V.: neighborly relationships, reality television, and differences between front and back yards.

It is a form of vicarious wish fulfillment for homeowners to watch these shows and see professional landscape architects and designers reinvent backyards for these families with luxurious fire pits, swimming pools, gardens and the like for free. Although many homeowners fantasize about an immaculately designed and maintained backyard, there are very few who have the resources to execute or utilize it to that level.

One popular genre of television is home makeover shows that focus on renovations and improvements to existing properties. These shows are the bread and butter of cable networks such as HGTV.

accessory dwelling units

NEIGHBORS In television shows, yards can be spaces of socialization that form & strengthen interpersonal relationships between characters. The most notable example of this is the popular sitcom from the 90s, Home Improvement. In the show, patriarch Tim Taylor (portrayed by Tim Allen), frequently engages with his neighbor, Wilson, across the fence that separates their respective backyards. Although the audience never sees the rest the Wilson’s face beyond what pokes up above the fence, a connection is formed. This leads to some interesting implications about how the show reflects the self-centered nature of homeowners. Tim, the show’s protagonist, and his backyard is fully exposed to the viewer and to his neighbor, who is tall is enough to see over the fence. However, the audience can never see into, and therefore never cares about, what is happening in the next yard over. This mentality is indicated in the same way NIMBY-ers only prioritize what they can experience in their own back yards. Opposite Left: Photo of the hosts of “Going Yard” on HGTV. Opposite Right: Promotional photo of a host on “Yard Crashers” on the DIY Network. Top: Still from “Home Improvement” of actors Tim Allen and Earl Hindman as neighbors. Bottom: Still from opening credits of “That 70’s Show” featuring charachters in front of the garage 19

introduction / political + cultural contexts

FRONT + BACK One of the most compelling idiosyncrasies of yard representation in sitcoms is that front yards tend to shown as footage of a real, existing property that was shot outside, whereas scenes shot in backyards are captured on a soundstage in an artificial environment. The stills to the right showcase the home of one of American culture’s most popular televised families, The Brady Bunch. From the outside, the home appears to be a relatively typical suburban, ranch-style home. It sets the scene for the series; the style of home, the neighborhood, even the Volvo Station Wagon out front all establish that this show is about a middle-class family. TV Tropes, a website that catalogs the devices and conventions commonly employed by the writers and producers of shows have explored this phenomenon. “When shown in establishing shots, often the outside doesn’t bear any resemblance to the inside, with different arrangements of windows and doors. Sometimes the house will have way more rooms inside than would be plausible for a house the same size as the one used for the exterior shots.” The actors are not even present in the scene, because this is about conveying the concept of place, not people. However all of these methods of representation change when it comes time for T.V. shows to get to the 20

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backyard. The backyard functions as an extension of the interior of the home. It is filmed indoors, created out of AstroTurf on a sound stage with painted sky and plastic plants. It exists solely for when plot lines call for specific outdoor activities. This same technique has been used repeatedly in T.V. shows for decades, including, but not limited to, Full House (pictured above), Boy Meets World, and Gilmore Girls. This manifestation of rear yards in TV is both reflective of and reinforcing to American society’s notions of the backyard. It promotes a sense of privacy and isolation from others, while functioning as a venue for familial bonding; essentially an outdoor

living room. This attitude works against Accessory Dwelling Unit development because when families are protective of their backyard, they may not want new inhabitants to encroaching on what they perceive as their personal space. Opposite Top: Still from an episode of the front yard of the house featured in “The Brady Bunch”. Opposite Bottom: Behind the scenes of “The Brady Bunch,” photo of soundstage backyard set piece. Top Left: Still from the opening sequence of “Full House” featuring the front yard condition. Top Right: Still from an episode of “Full House” featuring the backyard. Scene of a picnic. 21

introduction / social & political contexts

NATIONAL AND GLOBAL PERCEPTIONS OF THE BACKYARD The backyard has become a critical component to the “American Dream” since the widespread development of suburbs after World War II. America’s perception of the backyard may bring to mind motifs such as the white picket fence, teaching your child how to throw a ball, neighborhood barbeques, the family dog, and many more. Despite the reality of how little Americans actually use their backyard, these perceptions are sacred. Along with these common motifs, there are very distinct and rigidly enforced boundaries that go alongside a typical single-family home. Image 2 shows a standard suburban neighborhood. The homes all have a front yard with a driveway and garage, sufficient side yards to allow for plenty of privacy, and a backyard at the rear of the lot. All of the homes follow this same pattern. The backyard and sideyard are certainly private. So private, in fact, that when a family wants to build an additional floor, it often causes a major dispute because that family can now look directly into other neighbors’ yards. Disputes like this are common because it forces homeowners to accept the fact that the privacy they were promised is not the reality. The front yard participates in the public realm of the street, but it is undoubtedly within the perceptual boundary of the owner. The rare suburban pedestrian understands that there is a strict boundary at the front yard; the shared space of the suburb ends at the sidewalk. While this boundary is very apparent in suburban developments, it becomes slightly fuzzy in rural areas. Homes tend to be situated much farther back from their lot line. Image 1 shows a few floating homes with plenty of open 22

space around them. Despite the lack of clear definition between front, side, and back yard, these lots are no less private than typical suburbs. In effect, more open space does not equal shared space if it is not defined by the buildings around it. As housing typolologies densify, there are different relationships within backyards, shared space, and the public realm. Images 3-6 are examples of housing developments that have been standard to urban areas for hundreds of years. Image 3 is a neighborhood of two-to-four-story detached multi-family homes. There are small backyards, some alley conditions, and back or front porches. Because the backyard is typically small or nonexistent, much of the backyard’s function is delegated to the porch. When placed in the front of the house, the occupant has an immediate and active role in the street life. When placed in the back, it offers a quieter retreat. The lack of a front yard means that the building is only a few feet from the sidewalk. This clearly defines the public realm, engages the front porch, and creates the sense of constant “eyes” on the street. Image 4 is a typical rowhouse development with a back alley, rear fire escape and possible porch, and a consistent building profile throughout the block. The rowhouse layout engages with the street more so than Image 3 because the homes are attached, providing a constant public boundary. Backyard functions are held in the back alley. Although alleys may just house parking and garbage cans, rowhouse alleys can also be lively and multi-functional spaces for the entire

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Image 1: single-family rural

Image 4: low-rise rowhouses

Image 2: single-family suburban

Image 5: low to mid-rise courtyard apartments

Image 3: low-rise 2-4 family homes

Image 6: mid-rise housing block apartments 23

introduction / social & political contexts

block to interact. Additionally, rowhouse-dominated communities (as well as courtyard typologies) are more likely to have public parks nearby. Courtyard apartments behave similarly to rowhouse typologies (Image 5). Like the back alley, courtyards can be very pleasant or unpleasant. The smallest courtyards are built to maximize daylight penetration and are likely just large enough for garbage cans and a bit of sunlight. Most courtyards, however, have some sort of designated outdoor space for all residents to share. With the courtyard typology there is a clear divide between the public realm, private space, and shared space for residents only. The housing block apartment (Image 6) begins to blur this divide. The housing block layout features several long bars that divide and frame spaces within large and open blocks. Any space that is not built upon is left as semi-public green space. The open space is not only shared by neighborhood residents, but it can also be occupied by passing pedestrians. Most housing blocks also feature porches for private outdoor access for residents. In effect, the housing block features the most shared space and provides a mix of private and public outdoor spaces. While the built form of housing typologies has long promoted shared spaces, the social model of cohousing has also been central to some of the earliest civilizations. Cohousing simply means an intentional community of private homes clustered around shared space, and it is most commonly seen in both historical and present villages. Historically speaking, villages were 24

Dutch cohousing community, Centraal Wonen

Dutch cohousing community, Wandelmeent

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typically a community of five to thirty families. Homes were clustered together, often concentrically, for both defense and socialization, and the surrounding land held farms and pastures. Cohousing was seen as vital for the elderly, young children, or the disabled. Despite the fact that cohousing is an ancient concept that is still regularly seen today, cohousing has become a hot topic within the last fifty years of housing development. Cohousing has been popularized in Europe, and began in Denmark in the 1970’s. Danish cohousing tends to be rural in nature, and homes are often low-tech straw dwellings built by the new resident and the existing community. Danishing cohousing emphasizes sustainable and simple living. The Netherlands has a booming cohousing environment, which began in the mid-1970’s. Slightly more urban than Danish cohousing, Dutch cohousing features low-rise clustered housing with shared common facilities such as dining rooms and other social living spaces. Dutch cohousing is publicly funded, but inhabitants are allowed to choose who can move in. Sweden’s cohousing movement began in the late 1970’s as a massive state-funded welfare and affordable housing program. Furthermore, most Swedish cohousing also shares space with public companies, such as health centers, which allow some spaces to be community-occupied after six o’clock. Sweden’s cohousing is vertically-oriented, rather than Danish or Dutch, and tends to be located in the city center. Italy is one of the few Mediterranean countries that has whole-heartedly committed to the cohousing model. They have focused on two different means of cohousing devel-

opment. The first of which is Cohousing Venture, a consultancy firm that can design and occupy cohousing developments within two years. However, the rents will quickly fluctuate in the Italian economy. CoHabitando and CoAbitare offer a solution as nonprofits that cap rent prices. With both models there is a distinct focus on the benefits of cohousing for the elderly. There are also cohousing communities all over the United States. These tend to be similar to Danish or Dutch cohousing and emphasize sustainable and community living. Accessorry Dwelling Units also challenge the standards of the American single-family backyard. With accessorry dwelling units, the primary home must find ways to share or divide yard space in a way that’s suitable

Casa Verde cohousing development - Colorado Springs, CO 25

introduction / social & political contexts

for the ADU, the host, and neighbors. Single-family homes often have a great deal of yard space, much of it unused. ADUâ&#x20AC;&#x2122;s capitalize on this underutilized space for entries and secondary backyards. There are several strategies that have been effective in this regard. The first and most common strategy is to design ADU access on the opposite side of the house as the primary dwelling unit. For example, if the host enters through the front door facing the street, the ADU entry may be located on the side or back of the home (Image 7). The ADU then feels some sense of ownership towards the side yard, a space that is rarely used by the homeowner. This strategy is facilitated by a back alley or corner lot. In an alley condition, the ADU approaches the entry from the back (Image 8). In theory, the ADU and host could potentially never see each other unless they wanted to. A corner lot accomplishes a similar thing - the ADU enters from the side, and the host enters from the front (Image 9). Another strategy is to provide the ADU with their own porch, either at ground level or higher (Image 10). By doing this, the ADU has its own clearly defined backyard space - the ADU will not intrude on the homeâ&#x20AC;&#x2122;s backyard or vice versa. A similar strategy relies on landscaping to clearly define the boundaries of the ADUâ&#x20AC;&#x2122;s backyard. This can be done with paving, plantings, or larger plants which will also restrict views (Image 11). Although not as rigid as the porch barriers, there is still a clear understanding of which space belongs to whom. With all of these strategies there is a choice as to how much space will be shared and the amount of socialization desired 26

Image 7: Separating entry paths for division of yard space 47th St.

2nd Ave. NW

Image 8: Utilizing corner lot for separating entry paths and yard space University St.

University Alley

Image 9: Utilizing alley condition for separating entry and yard space

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between host and ADU. Many people build ADUâ&#x20AC;&#x2122;s for social reasons and enjoy sharing their backyard space, particularly if the ADU is designed for elderly parents, adult children, or friends. Others merely desire additional income and would rather not socialize with their tenants. Regardless, there are several ways to challange the boundaries of the single-family backyard to create new housing situations. Image 10: Dividing yard space with ADU porch

NE Rodney Ave.

Image 11: Landscaping strategies for dividing yard space

As traditional dense housing developments, cohousing models, and accessorry dwelling units are gaining in popularity, Americans are beginning to challenge the standards of the single-family suburban backyard. People are starting to question if the zoning codes and suburban blocks developed after World War II still reflect the ideals of Americans today. The economic recession beginning in 2008, record levels of student debt, unchecked sprawl, and the growing financial and environmental costs of automobile dependent development have all spurred a general shift in the way Americans are interpreting backyards and shared space. Many Americans are beginning to call for a loosening of the strict Euclidean single-use zoning code that has laid out Americaâ&#x20AC;&#x2122;s suburbs for the last eighty years.

Image 12: Separating entries, porch and landscaping to define boundaries 27

introduction / social & political contexts

THE PSYCHOLOGY OF NIMBYISM “Not In My Backyard” or NIMBY is an American phenomenon in which homeowners and other residents oppose certain development near their property. In many cases, residents will agree that controversial development such as affordable housing, mixed-use development, commercial districts, or industrial sites are necessary to society, but vehemently oppose it when that development is planned near their property. NIMBYs have developed an extremely negative connotation in the development and political field, sometimes even referred to as CAVE people (Citizens Against Virtually Everything). However, it’s important to understand why there are NIMBYs if developers and designers are to find a way to effectively and sensitively reach compromises. The first, and perhaps the most influential reason why NIMBYs exist is because of financial reasons. The vast majority of NIMBYs are homeowners. For many Americans, buying a home is the single greatest investment they will ever make. Retirement funds, college funds, and a bulk portion of total assets are rolled into one investment. The average household has 66% of all of their total assets in real estate, and over half of households do not have major investments in anything other than their home. Not only does a home represent a bulk of the homeowner’s financial assets, but it is also an uninsurable asset. Owning a home is a highrisk, high-return asset. A home’s value is susceptible to ups and downs in local, regional, national, and global trends. Among this list, there are 28

few things that are within the control of the homeowner. At such a state of helplessness to larger economies, NIMBYs are simply trying to mitigate local detriments to a home’s value such as health hazards, congestion, school quality, crime rates, air pollution, and open space. Desire for privacy is another frequently cited demand for NIMBYs. However, studies have shown that although a single family home is the major preference for Americans, most will trade a bigger backyard and house for a greater sense of community, easy walkability to shops and restaurants, nearby friends and family, and a shorter commute - all of which imply denser development. Renters generally do not participate in NIMBYism. They are not a part of this risky asset, and can simply move if their neighborhood is no longer to their liking. Even apartment owners are not as inclined to NIMBYism. Their investment is a distributed risk. If there are multiple investors on a single asset, in this case a house, the risk is far less for any one person. Despite the evidence that NIMBYism arises from a flawed financial market, a home is much more than a financial asset. A home is also an emotional connection to family, childhood, and all of the comforts of home. When many people buy a home they are planning to begin a marriage, raise a family, or start a new life there. There are emotional associations to the home that are deeply rooted in American society. When buying a home, the investor is also the consumer, so it only makes sense that they will have a

accessory dwelling units

high personal attachment to their investment. Furthermore, buying a home means that the buyer is also essentially buying the neighborhood as it was at the time the home was bought. Any changes that occur are a violation of the immaculate condition in which it was purchased. In fact, the more recently a homeowner purchased a house, the more likely they are to protest any future development. Long-time residents are actually significantly less prone to oppose development. Finally, a NIMBY is sometimes a NIMBY because they are right. Some developments should not be built in certain locations; some projects will actually harm the neighborhood as a whole and not just a handful of homes’ values; some developments are truly unwanted. However, it’s difficult to perceive these genuine complaints because so much of NIMBYism is focused on the financial and personal needs of individuals. It’s hard to blame homeowners trying to protect their greatest investment, but it’s also difficult for developers to navigate through so many dissenting opinions. It’s unlikely that NIMBYism can be resolved by means of political reform, as any compromise will not change the fact that homeowners are trying to protect a large uninsurable asset. It’s more likely that NIMBYism could be resolved through more efficient financial systems. One of the more controversial methods is to reduce homeownership. If more people were to rent rather than own their homes, they would be free to invest in more stable and insurable assets, while having the freedom to decide between moving frequently or

staying in one neighborhood. This is unlikely to be a favorable solution, however, as homeownership is deeply embedded in American culture and a critical component of the “American Dream.” Another solution to NIMBYism is to establish homeowner partnerships, in which the risk and equity of homeownership are distributed between multiple owners. Condominiums begin to achieve this, and home ownership associations begin to scratch the surface, but neither are suitable financial safeguards for single family homes. The third idea for combatting NIMBYism is to create home equity assurance, essentially making homeownership an insurable asset. However it is unlikely that an institution will voluntarily be held responsible for this financial burden. Until a feasible solution is presented, it’s critical that developers, designers, and politicans understand the needs and fears of NIMBYs if a solution is to be met.

PRECEDENTS Precedent studies of zoning, ADU buildings, small dwellings and co-housing provide background analysis and were used as a starting point to inform research. This information sets examples to refer to when implementing an ADU system and culture in Boston. Zoning precedents look at other cities with ADU systems in place while other studies on various housing types look more at design strategies as they apply to ADUâ&#x20AC;&#x2122;s. ADU precedent studies provide information about siting. Small dwellings provide examples for internal space planning and organization. Co-housing reveals social enhancements and benefits as a result of group housing in general.

introduction / precedents

ZONING PRECEDENTS CLASSIFICATION CITIES

austin

boulder

nashville

philadelphia

portland

san francisco

seattle

vancouver

PARKING LABELS

REQUIRED [space]

DIMENSIONS MAX. HEIGHT [feet]

ATTACHED

adu

DETACHED

alley flat ATTACHED

adu

district dependent

DETACHED

limited accessory unit ATTACHED

accessory apartment DETACHED

accessory dwelling ATTACHED

in-law suite DETACHED

adu

ATTACHED

adu

DETACHED

adu

ATTACHED

adu

DETACHED

adu

district dependent

adu

DETACHED

backyard cottage secondary suite DETACBED

laneway house

850+550 850 for 1st floor, 550 for 2nd

1,000

<20% primary unit area for lau

800/1000 dependent on lot size [10,000sf]

800

area of living space, not gfa

800

<75% primary unit area

600

RH-1 zone no limit in others

650/1000 12-23 range by

ATTACHED

MAX. AREA [feet2]

lot width

district dependent

detached limit vs. attachted limit

500

or <99% primary area for attached

OCCUPANCY OWNER [on site]

TENANTS [#]

accessory dwelling units

Comparative zoning precedents provide information about cities with established ADU cultures and looks to their respective zoning codes for examples. Portland, Seattle, Vancouver, San Francisco, Boulder, Austin, Nashville, and Philadelphia were all included under the study as areas where ADUâ&#x20AC;&#x2122;s are both legal and well integrated. Each city had different requirements and characteristics in their ADU zoning, some cities more loose and some cities more strict. Trends amongst these cities were looked at in terms of general zoning elements such as parking, ADU dimensioning, and occupancy. A further investigation was carried out in terms of ADU incorporation into existing services and utilities on a site. Exterior design standards were also looked at. Finally, typical block typologies were looked at and compared to Boston to see where certain borrowed zoning regulations might work best in different Boston neighborhoods. This is a way for the city of Boston to compare itself to cities with existing ADU zoning code and use their experience and expertise to help inform the city on a policy that works specifically for Boston in regards to ADUâ&#x20AC;&#x2122;s.

ZONING MECHANISMS Front Yard Setback

Rear Yard Setback

Side Yard Setback

Setback from Primary Structure

Unit Count/ Density Cap

Boudler Portland San Francisco Philadelphia Austin Seattle Nashville

ADU-Specific Base Zoning Provisions for Existing Structures Dependent on Base Zoning for Primary Structure No Specified Provisions Municipal Zoning Prohibits This

intodurction / precedents

ADU PRECEDENTS

ADU “Think Tank” - Savannah, Georgia 34

accessory dwelling units

Precedent studies involving actual ADU building precedents get deeper into site specifications for these buildings. Important factors are access and entry sequences, shared outdoor space amongst tenant and owner, and siting adjacencies such as alleyways and street frontages. Six different types of ADU typologies were looked at: The ‘New Build’ typology refers to an ADU structure that is a new construction and built within the footprint of the original dwelling The ‘Carve Out’ typology describes an ADU that is constructed out of a piece of an existing dwelling and is therefore attached and embedded within the original dwelling.

ADU - San Francisco, CA

The ‘Addition’ typology exists as a new construction that is physically attached to the primary dwelling structure The ‘Detached’ typology is a new construction that is separate from the original dwelling. The ‘Barnacle’ typology is a small ADU that attaches to the original dwelling and is structurally dependent on the home The ‘Garage’ typology is a conversion of an attached or detached existing garage into an ADU ADU - Seattle, Washington 35

introduction / precedents

SMALL DWELLING PRECEDENTS

All I Own House - Paris 36

accessory dwelling units

Small dwelling precedents were looked at on both a qualitative and quantitative basis. The study is broken up into two sections. 1. Efficient Design a. planar organization b. sectional organization 2. Convertible Spaces a. movable walls b. popup furniture Qualitative information consists of spatial arrangement of small dwelling spaces. Creative uses of storage and flexible layouts were two key qualities identified.

DR LR

Quantitative data involves area ratios to determine compact functionality. Overlapping functions within a space can be calculated through a programmed space metric in which spaces that serve multiple functions are counted twice towards a unitâ&#x20AC;&#x2122;s overall area. The more programmed space a unit has, the more spatially efficient it is.

The Tiny Project - Sebastopol, CA 37

introduction / precedents

CO-HOUSING PRECEDENTS

Puyallup Longhouse - Tacoma, WA 38

accessory dwelling units

Co-housing is a new paradigm in housing that starts to redefine the boundaries and traditional setup of a dwelling. It started in Europe in the 1960’s and has begun its move into America successfully. It is defined as a community composed of private homes supplemented by shared facilities to bring social, economical, and environmental benefits. This paradigm is seen as a new way to meet housing needs that creatively fit into our cities. These dwellings are usually planned, owned and managed by residents. Shared activities can include: dining, cooking, childcare, gardening, and governance with corresponding shared program. Co-housing and the beneficial relationships created through it are very applicable to ADU’s. Lange Eng Collective Living - Copenhagen

RELATIONSHIPS NUCLEAR FAMILY

ELDERLY

PARENTS

STUDENT OR RECENT GRAD

NUCLEAR FAMILY

SINGLE PARENT

NUCLEAR FAMILY

With diverse groups occupying one site at any scale, potential for this type of dynamic relationship is natural and can be enriching for both owners and tenants of ADU’s. Lange Eng Collective Living - Copenhagen 39

introduction / precedents

CO-HOUSING PRECEDENTS

Jamaica Plain Co-housing - Jamaica Plain 40

accessory dwelling units

The design and siting of co-housing in itself fosters beneficial social encounters by subtle but impactful differences from traditional housing. Often co-housing involves large courtyard spaces meant to be shared amongst members. Entry sequences that are not adjacent and facing the street also facilitate interaction amongst residents. A result is often a feeling of community within the dwellings that is more privatized from the general public. ADUâ&#x20AC;&#x2122;s create similar conditions by means of their siting and design. For example, an entrance to an ADU dwelling often occurs in the shared backyard space between tenants and owners. This activates the backyard as a shared space where natural encounters between residents occur. This subtle condition creates a more integrated dynamic than the more typical neighbor condition of two entrances each facing and adjacent to the street. Similar situations are created in carve out ADU situations where often the tenant must walk through the primary dwelling to get into their own.

Jamaica Plain Co-housing - Jamaica Plain

Co-housing has already been implemented successfully in Boston in the neighborhood of Jamaica Plain. The project facilitates neighborly interaction through a internalized shared courtyard while still providing each resident with their own more private, decentralized entrance to their units many of which occur in the interior of the courtyard. Lilac Co-housing - Leeds, UK 41

OPPORTUNITY MAPPING + ANALYSIS MARKET POTENTIAL BOSTON ZONING NEIGHBORHOODS

46 60 78

The purpose of this chapter is to identify and quantify the potential dispersion of accessory dwelling units in Boston. In order to clarify this goal, the chapter is organized into three sections, which together cover market potential, Boston mapping, and specific neighborhood analysis. The analysis conducted here focuses both on physical characteristics of residential parcels and on the current zoning policies that govern their use. Through the isolation of individual variables of each, the impact of the elements can be visualized and then inform a larger adjustment to current code that may eventually regulate the development of ADUs in the city.

The exercises detailed in this chapter are processoriented and data-generative; they are geared towards the creation of a large catalog of policy components, as opposed to a single prescriptive strategy. The information presented in the following pages is intended to inform the specific and nuanced decisions of the Boston Redevelopment Authority that will more concretely define where ADUs may and may not exist. The study draws its raw data from the City of Boston Assessing Departmentâ&#x20AC;&#x2122;s records (2014), the BRAâ&#x20AC;&#x2122;s Zoning Code (2015), and independent spatial analysis. This data was then processed for output using ArcMap, a type of Geographic Information System software and then edited in Adobe Illustrator during post-processing. 45

MARKET POTENITAL Opportunities for accessory dwelling units abound across the residential areas of Boston. The viability of these projects is determined by the socio-economic factors of housing need, construction costs, and rental prices. This section will identify, characterize, and locate the demographic types that stand to benefit most from the construction of ADUs and the resulting increase in lower-cost housing stock in Boston. One of the areas of greatest potential development is among Bostonâ&#x20AC;&#x2122;s senior population. There is an increasing desire among the elderly to age in place, but many senior citizens or other individuals with mobility restrictions do not use their own homes to their full extent. Additionally, many also struggle to maintain their homes financially when no longer working. Therefore, older property owners would benefit from ADUs because they would be able to live in the smaller unit themselves while gathering income from the rental of the larger home. Beyond the elderly and disabled populations, Boston has large numbers of potential renters who would benefit from smaller living spaces. After the initial demographic overview indicating where and why there is the most potential demand for ADUs by both owners and renters, the second portion of this section focuses on mapping the fiscal aspects of development and rent. The goal is to select for census tracts where construction is financially feasible in order to identify the areas of greatest opportunity in the City of Boston. 46

opportunity mapping + analysis / market potential

DEMOGRAPHICS The first step in deducing the market potential for ADUs is the identification of lower-cost housing needs in the Boston population. This study identified five primary demographic sub-groups that have the greatest likely use for ADUs: higher-education students, young professionals, new families, disabled adults, and senior citizens. The map on this page indicates the neighborhoods with the greatest densities of these specific tenant types. The matrix on the opposite page provides a brief and analysis characterization of the typical members of each sub-group. Percentage calculations are based on a population size of 617,529 persons unless otherwise noted. All data is derived from the 2010 census and should be considered as an approximation.

Brighton, Allston, + Kenmore

Allston, Dorchester, + Back Bay

Roslindale, South End, + Dorchester

Roxbury, Mattapan, + Jamaica Plain

West Roxbury, Roslindale, + Hyde Park

definition HIGHER-ED STUDENTS

undergraduate or graduate students in class full or part time at a higher learning institution

YOUNG PROFESSIONALS

white-collar workers new to their field + possessing a bachelorâ&#x20AC;&#x2122;s degree or higher

NEW FAMILIES

recently married couples or young families with one small child

DISABLED ADULTS

adults with cognitive or physical disabilities such as ambulatory or visual imparements

SENIOR CITIZENS

elderly individuals or couples over the age of sixty-five + retired or semi-retired

population

age

income

finances

33%

18-25

no/low

unemployed or part-time

40%

22-35

low/mid

$30,000 of student debt

10%

25-40

low/mid

two-income household

18-65

low/fixed

disabiltiy benefits

10%

65+

low/fixed

retirement savings

[of households]

opportunity mapping + analysis / market potential

BRIGHTON/ALLSTON

WEST ROXBURY

HYDE PARK

accessory dwelling units

VACANCY RATES The map on the opposite page illustrates the percentage of vacant units in a given census block group. Vacancy rates are defined as the percentage of unoccupied residences out of the total number of residential units within each census tract. The lightest shade of blue indicates the lowest percentage of vacant units identified - vacancy rates from zero to three percent, or in other words occupancy rates ninety-seven to one hundred percent. The darkest shade signifies a vacancy rate of twenty percent or greater, which is extremely high for urban areas. Since this data comes from the 2010 United States Census, it is not an entirely accurate reflection of the current housing climate in Boston, which has rebounded even further since the 2008 recession. Vacancy rates are a result of gap between supply and demand in the real estate market. With that in mind, the areas shaded in the lightest tones would benefit the most from the increased housing stock, as the market likely has sufficient demand and greater capacity to absorb new Accessory Dwelling Units. The neighborhoods of Jamaica Plain, Hyde Park, Roslindale, and West Roxbury have the lowest percentages of vacant residences, and therefore the most market capacity for additional units. Conversely, it is apparent that the neighborhoods of Roxbury, Mattapan, and Dorchester have greatest proportion of vacant residences, and therefore the least market capacity for additional units. 51

opportunity mapping + analysis / market potential

BRIGHTON/ALLSTON

JAMAICA PLAIN

WEST ROXBURY

accessory dwelling units

RENTAL RATES

This map illustrates the distribution of median contract rent values across the census block groups within the City of Boston. Median rent for a given census tract is calculated as the mid-range value of the monthly rates charged per unit for every residence in that region. The lightest blue shade indicates the lowest median contract rent values under $500 per month in the specified census tract. The darkest shade of blue represents the highest median contract rent values, which are those greater than $1700 per month. The map identifies areas where Accessory Dwelling Unit owners may be able to fetch higher rental income based on the distribution of the existing market value rental contracts. The neighborhoods of downtown Boston, Back Bay, Jamaica Plain, Allston/Brighton, and West Roxbury stand out with comparably high values, while the neighborhoods of Roxbury, Dorchester, and Roslindale have lower rent values. This data in combination with our examinations of assessed values of property and vacancy rates of residences can begin to frame an understanding of the rental real estate market in Boston.

opportunity mapping + analysis / market potential

CHARLESTOWN

JAMAICA PLAIN

DORCHESTER

accessory dwelling units

BUILDING VALUES + NEW CONSTRUCTION This map displays the parcels that contain at least one affordable housing unit overlaid on census block groups which are weighted by the average assessed building value per gross square footage of the residential projects within them. The Boston Redevelopment Authority, in collaboration with Bostonâ&#x20AC;&#x2122;s Office of Fair Housing and Equity, defines affordable units as privately-owned rental-tenure residences that are voluntarily price-capped in order to lower vacancy rates and create more housing opportunities for middle-income households. These developments have city imposed rent contract maximums and may be used to help identify areas of the city where the market rental value may not be great enough to justify Accessory Dwelling Unit construction. Areas with many affordable units typically indicate a market where demand for housing is not meeting the supply at the asked rent prices. The average assessed building value per gross square footage of residential projects can also help us identify the strength of the real estate market. Areas with higher values will likely allow Accessory Dwelling Unit owners to ask for higher rents and generate more income.

opportunity mapping + analysis / market potential

BRIGHTON/ALLSTON

JAMAICA PLAIN

DORCHESTER

accessory dwelling units

RENTAL UNITS

The map on the opposite page of this spread visualizes the percentage of residential parcels in a block group occupied by someone with a rental contract. The percentages are mapped as a shading gradient across the block groups of Suffolk County. The data displayed comes directly from the U.S. Census Bureauâ&#x20AC;&#x2122;s analysis of Bostonâ&#x20AC;&#x2122;s housing stock and rent tenure. The distribution of rental properties in the city can help define potential markets for Accessory Dwelling Units as an income generator for the property owner. A homeowner living in an area with an otherwise high rent tenure percentage can reasonably expect to find a tenant for a potential ADU unit on their property.

opportunity mapping + analysis / market potential

SOUTH BOSTON

DORCHESTER

HYDE PARK

accessory dwelling units

UNITS PER ACRE + SMALL PARCELS This map displays multiple layers of information. The first is housing density shown as a gradient across Suffolk Countyâ&#x20AC;&#x2122;s census block groups. The second is the location of small vacant lots with potential for development shown as points across the map. The Boston Redevelopment Authority defines housing density by units per acre of developable land. The metric used to generate the map to the left followed this definition with a small adjustment, dividing the sum of all reported housing units in a block group by the sum of the land area of all developed residential parcels. This isolates the current housing stock and the parcels used in this study for easy comparison across the city. The vacant lots displayed have a land area between 250 sq. ft. and 800 sq. ft. in order to isolate lots ideal for the type of small housing development this study advocates. Additionally, we imposed a maximum length to width ratio of 4:1 on the vacant lots in order to eliminate extremely narrow, undevelopable lots The resulting overlay suggests potential to raise housing density in areas of the city with a large number of these small vacant lots. Homes built on the lots would be primary dwellings rather than Accessory Dwelling Units, but the concept of small scale development to raise the housing stock in areas of need remains intact.

BOSTON ZONING This section contains a series of maps of the city proper with overlays applied in order to represent the parcels available for potential accessory dwelling unit development. The permutations test the effects of various relevant code requirements on the number of developable lots. The selected regulations are derived from current Boston zoning code, as well as from the documents of other cities with established ADU-specific legislation. The following variables are mapped individually and in combination in an attempt to best understand their effect on the implementation of a regulatory system for ADUs in Boston: primary structure, floor area ratio, open space, lot area, unit allowance, owner occupancy, financial independence, structure/site relationship, and height allowance. The data is intended to showcase the possibilities and limitations a modified zoning code could provide if ADUs become an accepted housing typology in Boston. The analysis for each restriction includes a map showing all of the parcels in Boston that meet that stipulation according to the data. There is also an equation and graphic illustration to convey what operation is being performed to identify and isolate these parcels. Additionally, each spread contains a pie chart, quantifying exactly how many parcels each map is showing. Many descriptions on the following spreads include excerpts from the Boston Redevelopment Authority, intended to clarify the current attitudes towards and definitions of certain zoning regulations. 60

opportunity mapping + analysis / boston zoning

PRIMARY STRUCTURE The first pertinent restriction to consider when considering the eligibility of parcels for an Accessory Dwelling Unit, is that the lot be residentially zoned with an existing structure currently located on site. The rational behind this restriction is that a dwelling unit can only be constructed in areas zoned for residential occupancy and that because it is an accessory unit, the ADU must be ancillary to a primary structure. According to the zoning code established by the Boston, MA Redevelopment Authority, â&#x20AC;&#x153;the purposes of the Residential Sub-districts are to maintain, enhance, and promote the character of residential neighborhoods in terms of density, housing type, and design; to discourage inappropriate forms of residential development such as basement dwelling units; to provide for low- and medium-density multifamily housing appropriate to the existing built environment; and to encourage appropriate development which enhances the Residential Sub-districts while preventing overdevelopment,â&#x20AC;? [Section 51-7]. There are four main types of residential sub-districts: one-family, two-family, three-family, and multifamily. Utilizing the information from the City of Boston Assessorâ&#x20AC;&#x2122;s Database, 75,843 parcels adhering to these two requirements were identified. In the following pages, this number will serve as the baseline for the maximum available parcels, with additional regulations further limiting the amount of eligible lots.

100%

75,843 / 75,843

EQUATION residentially zoned + building

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

OWNER-OCCUPIED This map examines and evaluates the status of the owner’s residence. According to the City of Boston, Assessing Department, owner occupancy is determined by whether the deed-holder of the parcel lives on the property or not. Applying this overlay reduces the number of eligible parcels by over one-third, down to 48,761 potential lots. This outcome indicates a policy of only permitting accessory dwelling units to be built on lots where the owner resides on site would not be overly prohibitive on development. Many other cities, such as Seattle, WA; Austin, TX; and Philadelphia, PA, include in their legislation a provision that owner’s who wish to construct ADUs on their property must also live on the property in question in either the primary structure or the accessory unit upon completion. The intent of this limitation is to curb development and prevent landlords with multiple properties from taking advantage of renters willing to live in smaller units. Overall it has been successful for these other cities in promoting a culture around ADU construction with an increased emphasis on aging in place. The Centers for Disease Control and Prevention (CDC) glossary of “Healthy Places Terminology” defines aging in place as, “the ability to live in one’s own home and community safely, independently, and comfortably, regardless of age, income, or ability level.” Through an owner-occupied ADU policy, elderly individuals or couples would be able to stay on their property in their current communities while renting out their primary structure. 64

64%

48,761 / 75,843

EQUATION residentially zoned + building + owner occupied

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

SINGLE-FAMILY This map displays all parcels containing a single family residence as defined by the Assessing Department’s property classification. There are 33,739 lots that meet these conditions, which constitutes 45% of the current housing stock in Boston. Coincidentally, many parcels that are single-family occupied are owner-occupied as well. As with the owner-occupied parcels, a policy oriented towards single-family residences will strengthen the ability of aging homeowners to reside in their communities in smaller, lower-maintenance structures. According to the zoning code established by the Boston Redevelopment Authority, One-Family Residential Sub-Districts are defined as being, “indicated by the designation ‘1F’ on said Maps. The One-Family Residential Sub-Districts are established to preserve, maintain and promote low density one-family neighborhoods, to provide for new infill construction appropriate to the existing fabric, and to allow minor changes to occur as-of-right. In a 1F Residential Sub-district, the maximum number of Dwelling Units allowed in a single Building shall be one,” [Section 517]. In the different neighborhoods of Boston, 1F Residential Sub-Districts can carry different zoning and development regulations regarding setbacks, FAR., open space, and other dimensional stipulations. Under current Boston zoning, these parcels would all be ineligible for an ADU, as no more than one unit are permitted by code.

45%

33,739 / 75,843

EQUATION 1F residentially zoned + single-family building

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

UNDER-UTILIZED This map displays parcels with fewer existing units than the maximum number allowed in that specific subdistrict under current zoning code. Typically, this parcel condition manifests as a three-family zoned lot with a one- or two-family home, or as a two-family zoned lot with a single-family residence. There are 22,020 parcels in Boston that meet this condition, representing 29% of the total current housing stock in Boston. This is significant for Accessory Dwelling Unit construction because the sites identified would allow for the addition of a new unit immediately, with no ADU-specific language added to the current zoning code necessary. The zoning code established by the Boston, MA Redevelopment Authority, states that parcels may be occupied by not more than the number of families specified by the use regulation for each residential sub-district. Multifamily sub-districts do not place a maximum on the number of units nor families that may occupy a parcel.

29%

22,020 / 75,843

EQUATION residentially zoned + building + (#units < zoned)

Although the mapped parcels meet occupancy standards for an additional unit, under current zoning code they are still subject to additional regulations regarding setbacks, FAR, open space, and other dimensional stipulations. A potential drawback of this overlay is that eliminates all parcels in single-family zoned areas, as they are already at their legal capacity of one.

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

FLOOR AREA RATIOS This map displays the parcels under the Floor Area Ratio (FAR) maximum designated by the zoning subdistrict. FAR is defined as the quotient of the gross floor area of the existing home and the lot area. Neighborhood code in Boston specifies a maximum FAR for all buildings in specific zoning sub-districts. There are 15,035 parcels in Boston that meet the limitations, constituting 20% of the studied housing market. In regards to on-site additions, the zoning code established by the Boston Redevelopment Authority, states that “the Floor Area Ratio of the existing Detached Dwelling or Main Building together with the new addition shall not exceed the maximum allowed Floor Area Ratio specified for the Subdistrict,” [Section 51-9]. This study assumes the minimum addition of a single ADU unit to the total gross floor area on a parcel as 250 sq. ft. The mapped parcels have gross square footage remaining to build out under current zoning regulations, however, they are still subject to regulations regarding setbacks, occupancy, lot area, usable open space, etc.

20%

15,035 / 75,843

EQUATION (gross building floor area + 250sf) / parcel area ≤ f.a.r. in zoning subdistrict

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

YARD DEPTH On this page is a map highlighting parcels with a yard depth of at least forty feet. To determine this, a box was offset forty feet from the existing primary structure in plan and at least one side of that building’s parcel boundary needed to fall outside of that zone.

50%

37,668 / 75,843

These lots are important to identify because they have the greatest potential for a new detached Accessory Dwelling Unit to be constructed. Ample yard depths and building setbacks are crucial in neighborhoods seeking to preserve density limits and maintain the character of the community. There are 37,668 parcels that meet this condition in Boston. According to the Boston Redevelopment Authority’s Zoning Code, “If on one lot there are two or more dwellings (other than temporary dwellings) designed for occupancy, or occupied, by one or more families, or if on one lot there are one or more such dwellings and one or more other main buildings, such dwellings shall be located no closer to one another and to such other buildings than if, and shall be separated by yards of the same minimum depths as if, each dwelling,” [Section 22-4].

40’0”

EXISTING STRUCTURE

40’0”

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

BUILDING SETBACKS On this page is a map highlighting parcels with existing structures that are located a distance greater than twenty feet from any other existing building on a neighboring parcel. To determine this, a box was offset twenty feet from existing primary structures in plan and no portions of those regions were permitted to overlap with another building’s region.

47%

35,429 / 75,843

These lots are important to identify because they have an increased potential for a new, detached Accessory Dwelling Unit to be constructed. Ample yard depths and building setbacks are crucial in neighborhoods seeking to preserve density limits and maintain the character of the community. There are 44,742 parcels that meet this condition in Boston. According to the Boston Redevelopment Authority’s Zoning Code, “where in a residential district a dwelling designed for occupancy or occupied by one or more families is on the same lot as, and to the rear of, another main building, the distance between such dwelling and such main building shall be not less than twice the minimum rear yard depth required by this code for such main building; and the requirements of this code with respect to lot size, open space, and front, rear and side yards shall apply as if such dwelling were on a separate lot,” [Section 14-5].

20’0”

EXISTING STRUCTURE

20’0”

20’0” 20’0”

20’0”

EXISTING STRUCTURE

20’0”

N 0 Â˝ 1

4 miles

opportunity mapping + analysis / boston zoning

SITE SETBACKS Here is a map indicating parcels with existing structures that possess sufficient lot area for a minimum 250 sq. ft. Accessory Dwelling Unit after subtracting the area negated for development by requisite setbacks. To determine which parcels meet these conditions, three setback requirements were identified: fifty feet from the center of the road, ten feet from an existing structure, and five feet from the edge of the lot line. There were 46,897 parcels selected that met this criteria for potential on-site hosting capabilities for ADUs. Setbacks are defined by the Boston Redevelopment Authority in their Zoning Code as, “Except as otherwise provided in this Article, where a minimum setback of parapet from lot line is specified in this code, neither the top line of the face of any wall of a structure within the district, and devoted to the use, specified, nor any cornice, eaves, parapet or other feature topping or overhanging such wall shall be closer to any lot line to which it is parallel or most nearly parallel than the distance specified in said Table B or, if such lot line abuts on a public open space or on one of two or more contiguous public open spaces, such distance minus whichever of the following is the lesser: (1) one half of the width of such open space or spaces, or (2) fifty feet,” [Section 21-1].

62%

46,897 / 75,843

5’0”

10’0”

EXISTING STRUCTURE

50’0”

N 0 Â˝ 1

4 miles

NEIGHBORHOODS This section contains a series of maps of five neighborhoods within Boston, plus the JP/Rox study area, with overlays applied in order to represent the conditions present for potential accessorary dwelling unit development. The neighborhoods chosen to analyze further are Dorchester, East Boston, Hyde Park, Jamaica Plain, and West Roxbury. These neighborhoods are further explored in the following chapter of this book. The permutations test the effects of various relevant code requirements on the number of developable lots. The selected regulations are derived from current Boston zoning code, as well as from the documents of other cities with established ADU-specific legislation. The variables selected to show at a neighborhood scale reflect the specific zoning requirements of these neighborhoods, as each differs from one another. We have elected to show a selection of maps for each neighborhood that displays the unique conditions that apply to that neighborhood, which might lend insight into the development approach suitable for that particular area. The analysis for each restriction includes a map showing all of the parcels in each neighborhood that meet that stipulation according to the data. For each neighborhood, there are pie charts, quantifying exactly how many parcels are being shown by the following maps, as well as a key indicating where this neighborhood is located in Boston. A diagram for each map helps illustrate what data the map is communicating. 78

opportunity mapping + analysis / neighborhoods

DORCHESTER Dorchester is a neighborhood with parcels that have a lot of adequate lot area to accomodate for the development of ADUs, and not a lot of room for vertical growth, under current zoning. As noted in the demographics section of this chapter, Dorchester is an area that appeals to Young Professionals and Young Families. These groups would likely prefer a Detached ADU, however, under current zoning, this neighborhood does not allow for a lot of detached units. This could be seen as an opportunity for adjustments to current zoning laws to meet this demand. Detached parcels meet the city and neighborhood requirements for: Unit Allowance (plus one unit), Lot Area (plus one unit), Open Space (plus one unit and 250 sq ft building footprint), and FAR (plus 250 gross sq ft).

61.4%

7.9%

4.3%

9231 / 15,027

1185 / 15,027

645 / 15,027

SITE SETBACKS

REMAINING HEIGHT

DETACHED

accessory dwelling units

SITE SETBACKS S

10’0”

50’0”

EXISTING STRUCTURE

5’0”

opportunity mappin ng + analysis / neighborhoods

3 STORY

REMAINING HEIGHT ALLOWANCE

accessory dwelling units

CURRENT ZONING ING - DETACHED

opportunity mapping + analysis / neighborhoods

EAST BOSTON While East Boston is one of the more dense neighborhoods examined, building parcels are known to be particularly deep, still providing many opportunities for the development of ADUs. For these reasons, Detached and Carve-Out ADUs seem like ideal building types for adding additional units in this neighborhood. It is important to note, however, that Owner Occupancy in this neighborhood is very low, thus building this into the requirements for this neighborhood would be quite limiting as compared to other neighborhoods in this study. Carve-Out parcels meed the city and neighborhood requirements for: Unit Allowance (plus one unit), Lot Area (plus one unit), Open Space (plus one unit), and FAR (plus 250 gross sq ft).

55.5%

43.8%

5.2%

2875 / 5,176

2269 / 5,176

267 / 5,176

OWNER OCCUPIED

SITE SETBACKS

CARVE-OUT

accessory dwelling units

OWNER OCCUPIED

opportunity mapping + analysis / neighborhoods

SITE SETBACKS

10’0”

50’0”

5’0”

EXISTING STRUCTURE

accessory dwelling units

CURRENT ZONING - CARVE-OUT

opportunity mapping + analysis / neighborhoods

HYDE PARK In the demographics section of this chapter, the Hyde Park neighborhood was cited as a good opportunity for elderly residents. It is a neighborhood with large lots that are almost entirely single- and two-family. Additionally, a vast majority of parcels are owneroccupied. Hyde Park is also significant for having the most remaining FAR available under current zoning, thus current zoning would allow this neighborhood to get much denser than it is. For these reasons, Hyde Park would be a good location for adjustments to the zoning code that would allow for ADU development. The least objectionable would likely be Carve-Outs or Attic Additions, however, the size of the lots in this area would allow for Detached ADUs that are far from other houses and the street.

39.0%

91.4%

77.6%

2953 / 7,568

6920 / 7,568

5870 / 7,568

REMAINING FAR

OPEN SPACE

OWNER OCCUPIED

accessory dwelling units

REMAINING FAR ALLOWANCE

FAR

opportunity mapping + analysis / neighborhoods

REMAINING OPEN SPACE

accessory dwelling units

OWNER OCCUPIED

opportunity mapping + analysis / neighborhoods

JAMAICA PLAIN The Jamaica Plain neighborhood has the best opportunity for ADU development under current zoning laws, of the neighborhoods examined here. JP has the highest percentage of parcels of any of the other neighborhoods examined that allow for Detached, Attic Addition, or Carve-Out style ADUs. For this reason, Jamaica Plain would likely be an ideal neighborhood for an ADU pilot program, given that a minimum of 261 parecls would be eligible with no changes needed. Attic Addition parcels meet the city and neighborhood requirements for: Unit Allowance (plus one unit), Lot Area (plus one unit), Open Space (plus one unit), and FAR (plus 250 gross sq ft). (Detached and Carve-Outs described previously).

7.6%

5.0%

9.3%

396 / 5,243

261 / 5,243

485 / 5,243

DETACHED

ATTIC

CARVE-OUT

accessory dwelling units

CURRENT ZONING - DETACHED

opportunity mapping + analysis / neighborhoods

CURRENT ZONING - ATTIC ADDITION

accessory dwelling units

CURRENT ZONING - CARVE-OUT

opportunity mapping + analysis / neighborhoods

WEST ROXBURY West Roxbury is a neighborhood characterized by large lots with single-family, owner-occupied homes. Like, Hyde Park, it is a neighborhood with significant opportunity for ADUs for the elderly. With these features, the physical attributes of the neighborhood are primed for ADUs, however current zoning allows development on less than 1% of parcels. This is because the laws in place seek to maintain the low density of the neighborhood. ADU development in West Roxbury will require adjustments to the zoning code and statutes that allow for increased density within the fabric of the neighborhood. Carve-outs for elderly relatives and/or utilization of large lots for detached units are likely the ideal options for ADUs in the West Roxbury neighborhood.

87.4%

84.3%

85.1%

7397 / 8,464

7134 / 8,464

7201 / 8,464

SITE SETBACKS

OWNER OCCUPIED

SINGLE FAMILY

accessory dwelling units

SITE SETBACKS

10’0”

50’0”

EXISTING STRUCTURE

5’0”

opportunity mapping + analysis / neighborhoods

OWNER OCCUPIED

accessory dwelling units

SINGLE FAMILY

opportunity mapping + analysis / neighborhoods

JP/ROX STUDY AREA The JP/Rox study area is part of a BRA planning initiative along Washington Street and Columbus Avenue between Forest Hills, Egleston Square, and Jackson Square, straddling Jamaica Plain and Roxbury. This area is currently home to mainly mixed-use and commercial/industrial buildings, interspersed with an even split of single-, two-, and three-family residences. The JP/Rox area is already quite dense with a comparatively low percentage of â&#x20AC;&#x153;large yards.â&#x20AC;? There does, however, appear to be adequate opportunity for buildings to grow vertically under current zoning code. Attic Addtions and Carve-Outs are likely the most optimal ADUs types for development in this area with little alterations needed to current zoning to allow them.

40.9%

259 / 634

REMAINING HEIGHT

100

29.8%

189 / 634

LARGE YARDS

12.5%

79 / 634

CARVE-OUT

accessory dwelling units

3 STORY

REMAINING HEIGHT ALLOWANCE

101

opportunity mapping + analysis / neighborhoods

LARGE YARDS 40’0”

40’0”

EXISTING STRUCTURE

40’0”

102

40’0”

accessory dwelling units

CURRENT ZONING - CARVE-OUT

103

NEIGHBORHOOD SCALE JAMAICA PLAIN HYDE PARK WEST ROXBURY EAST BOSTON DORCHESTER COMMERCIAL DISTRICT

108 130 150 170 202 220

105

106

As Boston expanded and developed into a city, it incorporated many of the neighboring communities. As a result, Bostonâ&#x20AC;&#x2122;s neighborhoods have each developed their own character, style, and code. When the city enacted its first zoning code in 1924, known as the 1924 act, these differences were brought into consideration. This resulted in 32 separate zoning codes for the city (14 neighborhood codes and 18 for downtown and the waterfront.) Each code was designed to ensure that new construction would match the context of whichever neighborhood it was being built in. As the 1924 Act became outdated, it still contained references to blacksmith shops and other antiquated uses, it was repealed and replaced with the 1956 Enabling Act. The Enabling Act granted the Boston Zoning Commission the authority to amend the code after consulting with the Boston Redevelopment Authority. Significant alterations were once again made to the codes in 1986 as part of a city-wide rezoning process. These reforms were made possible by Massachusetts Chapter 40A (1975); also known as the Zoning Act, which gave cities and towns greater freedom to dictate their own zoning. Many cities, including Boston, believed that down-zoning would be in their best interest and help preserve neighborhood character. The zoning reforms caused housing development to slow significantly, and in 2007

Massachusetts was ranked 46th in the country for new housing per capita. Despite many reforms, the 1924 Act remains the basis for large portions of the current zoning regulations in the city. After being introduced, the Boston zoning regulations have regularly been updated in roughly 30 year intervals that reflect the changing attitudes, technologies, and needs of the city. As we near the end of one of these 30 year periods, housing unit shortages are an increasing issue that the city must confront. As part of this analysis, we looked at how the existing neighborhood codes have affected the availability of housing. To get a clearer picture of the variation in zoning codes between neighborhoods, we have chosen five neighborhoods to explore in depth; Jamaica Plain, Hyde Park, West Roxbury, East Boston, and Dorchester. To better understand each neighborhood we established a typical block typology for each neighborhood. The typical block conditions were then used to determine what effects the current zoning has on available housing stock. We then used the information gathered from the typical blocks to test what effects minor changes to the existing building codes would have on the possibilities for ADU development.

107

JAMAICA PLAIN Jamaica Plain is a neighborhood in Boston with a size of 4.4 square miles. It was originally an area within West Roxbury, but later became part of Boston when both were annexed in 1874. In the past decade, Jamaica Plain has seen steady growth and development, with new residential and retail projects being built. The fabric of the neighborhood is comprised of both triple decker multi family housing, as well as smaller single family houses. As opposed to other neighborhoods in Boston, Jamaica Plain is known to have larger lot sizes and greater percentages of open space.

108

neigborhood scale / jamaica plain

PARKING total parcels

driveways garages + sheds parcel boundaries parking boundaries 17.9

gross sq ft per acre

27,442

parking per unit:

1.6

OFF ST

units per acre

ET RE

33%

total:

101

EET STR ON

67%

3F-4000

1F-5000

1 1

1 1 1

100

400 feet

neigborhood scale / jamaica plain

YARD SETBACKS

759 sf

157 sf

unbuildable area max

buildable area

min

size of accessory unit (allowable, 25% rear setback)

264 sf

ZONING Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000

100

400 feet

1F-5000

neigborhood scale / jamaica plain

two family

one family

LS CE AR

ELS RC

2 FAMILY

1 FAMIL YP

FLOOR AREA RATIOS

29%

three family

.02%

AMILY PARCE L 3F

42%

MILY PARCE FA LS -6

four-six family

ZONING

114

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000 1.01

.82

.70

1F-5000

.71

.46

.76

.99 .39

.75

.96

.98

.99 .76

1.08

.54

.59 .50

1.25

.37

.60

.84

.62

.53 .22

.89

.67

.59 .46 .63

.99 .76

.45

.60

.77

.63

.77

.25 .76

.82

.42 .44 .48

100

400 feet

.46

neigborhood scale / jamaica plain

UNUSED FAR under FAR limit

PA LEFTO VER FA ITH R SW EL RC

remaining FAR sf over FAR limit 44%

at FAR limit

ZONING

116

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000

1F-5000

-.12

-.31

-.01

733 sf

-.29

+.11

-.05 -.28

-.29

+.11

-.38

-.04

+.20

-.06

543 sf

-.14

+.10

1,193 sf

+.13

677 sf

-.26

1,4 79 sf

-.06

+.24

449 sf

382 sf

2,886 sf

+.17

-.55

+.08

686 sf

1,053 sf

+.48

-.19

1,340 sf

+.11

-.17

252 sf

+.24 +.07

-.29 -.06

+.25 +.07

-.07

-.10

+.45 -.27

1,672 sf 432 sf 5,384 sf

-.06

-.12

+.28 +.26 +.02

1,806 sf 1,598 sf

100

400 feet

133 sf

+.04 240 sf

neigborhood scale / jamaica plain

This scenario determines which parcels can accoomodate an ADU under current zoning regulations.

SCENARIO A - AS OF RIGHT satisfies requirement

UND ER US ED

does not satisfy new (attached/detached) basement/attic

G NIN ZO

23%

carve out units per acre

20.8

gross sq ft per acre

28,587

ZONING

118

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000

+2 +2

+2 +2 +1

100

400 feet

1F-5000

neigborhood scale / jamaica plain

This scenario determines which parcels can accoomodate an ADU when Lot Area and Lot Area per Additional Unit are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

SCENARIO B - DISREGARD LOT AREA satisfies requirement does not satisfy

PA RC S EL ADU ERE WH

new (attached/detached) basement/attic

IS POSSI BLE

44%

carve out units per acre

22.5

gross sq ft per acre

29,617.6

ZONING

120

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000

1F-5000

+1 +1

+1 +2 +2

+1 +1

+1 +2

+1 +1 +1

100

400 feet

neigborhood scale / jamaica plain

SCENARIO C - DISREGARD LOT AREA + FAR satisfies requirement

This scenario determines which parcels can accoomodate an ADU when Lot Area, Lot Area per Additional Unit, and FAR are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed. EA WHER DU IS PO LS SS CE IB R LE PA

does not satisfy new (attached/detached) basement/attic carve out units per acre

27.1

gross sq ft per acre

29,617.6

100%

ZONING

122

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-5000

5,000 sf

n/a

1,250 sf

20 ft

10 ft

20 ft

50 ft

3F-4000

4,000 sf

1,000 sf

600 per 1 200 per addâ&#x20AC;&#x2122;l

20 ft

10 ft

20 ft

40 ft

3F-4000 +1

1F-5000

+1 +1

+1 +2

+2 +1

+1 +1

+1 +1 +1

100

400 feet

neigborhood scale / jamaica plain

COMPILED DATA EXISTING CONDITIONS PARKING (per unit)

JAMAICA PLAIN

HYDE PARK

WEST ROXBURY

EAST BOSTON

DORCHESTER

124

1.6

2.9

.78

1.9

UNITS PER ACRE

ZONING SCENARIOS A

17.9

20.8

22.5

27.1

27,450

28,600

29,600

10.5

15.9

16.6

13,400

13,650

16,950

17,000

4.7

7.8

9.5

12,500

14,150

54.1

57.2

63.9

52,400

53,000

54,850

18.4

19.5

21.1

23.5

28,800

29,450

29,750

GROSS SQ FT PER ACRE

EAST BOSTON Most densely populated.

JAMAICA PLAIN Median increase in units per acre.

DORCHESTER Smallest increase in gross sq ft per acre.

WEST ROXBURY

Most parking spots per unit.

HYDE PARK Largest increase in gross sq ft per acre.

125

neighborhood scale / jamaica plain

LE BASEMENT SIB AD S U PO

CESS TO R Y AC EA A R W E YA V I R R D

LAR GE SI DE

ARD FOR N AR Y EW RE CO D N AN

ION CT RU ST

U AD

GE FOR PO ARA SS G IBL NG I E T IS

AY FOR AD UA IVEW R D CC T I ES L P S

CE FOR BAS UEN EM Q EN SE Y T R T

U AD

neighborhood scale / jamaica plain

PO S

FE NC IN

ALLEY ACCE SS EAR R FO E R BL I S

U AD

CY IVA PR

FOR BACKYAR ER DA D I V DU DI

HYDE PARK Hyde Park is the southern most neighborhood, located in the southwest corner of Boston. Hyde Park was annexxed in 1912, the last to be added to the city of Boston. Hyde Park offers larger open space within the neighrborhood with easy access to downtown Boston, providing a blend of city ammenities as well as a more quiet lifestyle. It is well known for its suburban characteristics in an urban location. The area was established in the 1660â&#x20AC;&#x2122;s and soon became the center of activity for cotton and paper manufactoring. But with the extensions to the rail lines, it became a perfect location for residential development. Hyde Park consists of a very diverse population. The residential buidings mostly consist of mid-twentieth centry single family homes among various historic buildings as well.

130

neighborhood scale / hyde park

PARKING total parcels

driveways garages + sheds parcel boundaries parking boundaries 10

gross sq ft per acre

13,370

parking per unit:

2.9

OFF ST

units per acre

ET RE

53%

total:

132

EET STR ON

47%

1F-60

2F-50

100

400 feet

neighborhood scale / hyde park

YARD SETBACKS

1,067 sf

unbuildable area

283 sf

max

buildable area

min

size of accessory unit (allowable, 25% rear setback)

578 sf

ZONING

134

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

1F-60

2F-50

100

400 feet

neighborhood scale / hyde park

1 FAMILY

one family

LS CE

two family

LS CE AR

2 FAM ILY

PA R

FLOOR AREA RATIOS

50%

three family

00%

-6

ILY PARCELS AM 3F

00%

PARCE LS MILY FA

four-six family

ZONING

136

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

.26 .41 .47 .32

.33

.48

.34 .18

.34 .41

.11

.38

.35

.27

.38

1F-60

.26

.24

.29

2F-50

.44 .27 .27 .28 .33

.29 .21

.31 .48 .33

100

400 feet

neighborhood scale / hyde park

UNUSED FAR under FAR limit

PAR CE LS H IT W

remaining FAR sf

VER FAR FTO LE

over FAR limit

44% 100%

at FAR limit

ZONING

138

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

1,920

+.24 450

218

+.09

893

+.03

119

+.18

+.17

+.02

762 688 915

535

+.16

+.32 2,125

+.16 +.39

+.09

+.15

5,134

758

678 716

+.12

+.23

+.17

335

+.06

+.21 +.19

1,026

889

1,108 1,131

+.23 +.29

2F-50

2,500

+.23

1,386

+.26

2,124

1,010

+.21

1F-60 00

+.24

1,290

+.12

1,106

+.22 +.02

2,778 128 1,297

+.17

100

400 feet

neighborhood scale / hyde park

This scenario determines which parcels can accoomodate an ADU under current zoning regulations.

SCENARIO A - AS OF RIGHT satisfies requirement does not satisfy

new (attached/detached)

BY SED RU E ND

ZONING

basement/attic 7%

carve out units per acre

10.5

gross sq ft per acre

13,655

ZONING

140

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

1F-60

2F-50

100

400 feet

neighborhood scale / hyde park

This scenario determines which parcels can accoomodate an ADU when Lot Area and Lot Area per Additional Unit are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

SCENARIO B - DISREGARD LOT AREA satisfies requirement does not satisfy

PAR CE LS W H IS DU EA ER

new (attached/detached)

POSSIBLE

basement/attic 89%

carve out units per acre

15.9

gross sq ft per acre

16,941

ZONING

142

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

+1 +1

+1 +1 +1 +1 +1

1F-60

+1 +1

2F-50

+1 +1

100

400 feet

neighborhood scale / hyde park

SCENARIO C - DISREGARD LOT AREA + FAR satisfies requirement

does not satisfy new (attached/detached) basement/attic carve out units per acre

16.6

gross sq ft per acre

16,941

100%

ZONING

144

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,850 sf

25 ft

10 ft

40 ft

60 ft

2F-5000

5,000 sf

3,000 sf

1,750 sf

20 ft

10 ft

40 ft

50 ft

+1 +1

+1 +1 +1 +1

1F-60

+1 +1

2F-50

+1 +1

100

400 feet

SCALE: 128” = 1

SK G

LON

R YARDS W/ DR IV

A RE

E IBL

CARVE OUT IN

ACCESS TO RE Y A AR EW

S IN LA RG

TURE

C RU

smaller backyard space, more concealed possible ADU conversion

larger backyard space, less concealed possible ADU construction

larger backyard space, moderately concealed possible ADU construction 149

WEST ROXBURY West Roxbury is located in the southwest corner of Boston. It was founded in 1630 and annexed by the city in 1847. Today the neighborhood exists as a suburb consisting of mainly single family homes on tree-lined streets. The lots are characterized as low density with plenty of existing open yard space. The total area of the neighborhood is 4.61 square miles with a population of about 30,446 people.

150

neigborhood scale / west roxbury

PARKING total parcels

driveways garages + sheds parcel boundaries parking boundaries 4.7

gross sq ft per acre

12,492

parking per unit:

OFF ST

units per acre

ET RE

35%

total:

65%

EET STR ON

total:

1F-8000 1F-6000

100 400

feet

neigborhood scale / west roxbury

YARD SETBACKS

1,626 sf

unbuildable area buildable area

max

383 sf

min

size of accessory unit (allowable, 25% rear setback)

745 sf

ZONING Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

1F-8000 1F-6000

100 400

feet

neigborhood scale / west roxbury

two family

one family

LS CE AR

ELS RC

2 FAMILY

1 FAMIL YP

FLOOR AREA RATIOS

100%

three family

AMILY PARCE L 3F

MILY PARCE FA LS -6

four-six family

ZONING

156

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

.18

.14

.23

.21

.15

.27

.23

.22

.32

.21 .26 .16

.40

.36

.45 .26

.32

.37

.34

.49

.35

.30

.33

.56

1F-8000 1F-6000 .31 N

.35

100 400

feet

.43

.40 .25

neigborhood scale / west roxbury

UNUSED FAR PARCELS W ITH LE FT

under FAR limit remaining FAR sf over FAR limit at FAR limit

R FA ER OV

59%

ZONING

158

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

1,205 sf 1,349 sf

+.18

2,330 sf

695 sf

+.16

+.12

+.07

+.09 1,931 sf

+.03

+.07

304 sf 1,410 sf

+.15

+.08 540 sf

833 sf

+.14

+.09 +.14

1,309 sf

-.10

2,373 sf

-.06

-.05 +.04

-.07

+.07

-.02 472 sf

-.04

-.19

0 0

-.05

-.16

1F-8000 1F-6000 +.09 621 sf

+.05 357 sf

100 400

feet

1,183 sf

-.03

+.15 1,632 sf

500 sf

neigborhood scale / west roxbury

SCENARIO A - AS OF RIGHT

This scenario determines which parcels can accoomodate an ADU under current zoning regulations.

satisfies requirement

UNDERU SED BY ZO

does not satisfy new (attached/detached) basement/attic

NG NI

carve out units per acre

4.7

gross sq ft per acre

12,492

ZONING

160

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

1F-8000 1F-6000

100 400

feet

neigborhood scale / west roxbury

This scenario determines which parcels can accoomodate an ADU when Lot Area and Lot Area per Additional Unit are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

SCENARIO B - DISREGARD LOT AREA satisfies requirement does not satisfy

PA E ADU IS POS HER SIB LE SW EL RC

new (attached/detached) basement/attic 66%

carve out units per acre

7.8

gross sq ft per acre

14,153

ZONING

162

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

+1 +1

0 +1

1F-8000 1F-6000 +1

100 400

feet

neigborhood scale / west roxbury

This scenario determines which parcels can accoomodate an ADU when Lot Area, Lot Area per Additional Unit, and FAR are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

SCENARIO C - DISREGARD LOT AREA FARvc satisfies requirement does not satisfy

ERE ADU IS POSS WH IBL LS E E C AR

new (attached/detached) basement/attic carve out 9.5

gross sq ft per acre

14,153

units per acre

100%

ZONING

164

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space/Unit

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

1F-6000

6,000 sf

n/a

1,800

20 ft

10 ft

30 ft

60 ft

1F-8000

8,000 sf

n/a

2,000

25 ft

12 ft

40 ft

+1 +1

1F-8000 1F-6000 +1

100 400

feet

neighborhood scale / west roxbury

POTENTIAL FOR NEW ADUâ&#x20AC;&#x2122;S

166

167

POTENTIAL FOR CONVERSION ADUâ&#x20AC;&#x2122;S

168

169

EAST BOSTON East Boston is a dense neighborhood located in the northeastern part of the city, with Logan Airport occupying the southeast corner of the neighborhood. A majority of the neighborhood is zoned for three family occupancies, with some areas zoned for 1 or 2 family residences. Typical blocks in East Boston are large, with an average width of 200 feet. The deep blocks combined with narrow parcel sizes, resulting in a dense street wall, create a private backyard area for most plots, that is difficult to see from the street. Trees and fences in backyards block views of most neighboring properties, except for those on the third floor or a roof deck. Triple deckers make up a majority of the existing housing in East Boston, but smaller two-story detached houses are also common. Many basement and attic spaces in the neighborhood have already been converted to additional living space limiting the possibility of converting these spaces. Some units have also converted and enclosed existing rear deck conditions, this same strategy can be used to provide a vertical ADU or to create additional living area for a carve-out located in the rear of the building. Deep backyards allow for the construction of new detached housing options behind existing buildings. Existing garages can also be converted into ADUs. They typically do not have an attic that could be converted, though most have basements (some already inhabited). 170

neigborhood scale / east boston

PARKING total parcels

driveways garages + sheds parcel boundaries parking boundaries 54.1

gross sq ft per acre

52,369

parking per unit:

.78

OFF ST

units per acre

ET RE

22%

total:

172

EET STR ON

78%

100

400 feet

east boston

YARD SETBACKS

380 sf

unbuildable area

0 sf

max. min.

buildable area size of accessory unit (allowable, 25% rear setback)

170 sf

ZONING

174

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

neigborhood scale / east boston

1 FAMILY

one family

two family

2 FAM ILY P

PA R

FLOOR AREA RATIOS

7.7%

CE AR

20.5%

three family

7.7%

-6

LY PARCELS AMI

64.1%

PARCE LS MILY FA

four-six family

ZONING

176

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

1.1

.5 1.7 1.6

1.6

.97

1.6

.84

.98

1.7 1.5

1.5

.48 1.5 1.4 1.5

1 3.1

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

.94

1.4

1.4 1.5

1.3

1.8

1.2

1.1

1.04

1.1

0 .64

.96

1.0

1.3

1.1

1.3

neigborhood scale / east boston

UNUSED FAR

under FAR limit

E LS

remaining FAR sf

IT H

LE FTO V E R

over FAR limit 20.5%

at FAR limit

ZONING

178

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

-.1

+.42

f 6s 78

-.7 -.6

-.6

-.6 +.03

sf 75

-.7 -.5 +.52

-.5 -.4 -.5

0 -2.1

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

+.1

-.4

+.02

f 1s f4 8s 8 3

sf 94 1,2

-.5

+.06

-.4

-.5 -.3

-.2

-.04

-.1

+.3 f 9s 62

f 5s 20

f 8s 13

-.8

-.1

+.04

-.06

-.3

-.1

-.3

neigborhood scale / east boston

POSSIBLE ADU PLOTS Y

IN G

satisfies requirement

N ZO

UND E RU

does not satisfy new (attached/detached) basement/attic

carve out units per acre

54.1

gross sq ft per acre

52,369

ZONING

180

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

neigborhood scale / east boston

POSSIBLE ADU PLOTS

satisfies requirement

E LS

does not satisfy

R E A D U IS

new (attached/detached) 15.3%

basement/attic

PO S

carve out

gross sq ft per acre

52,988

57.2

units per acre

ZONING

182

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

+1 +1

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

neigborhood scale / east boston

POTENTIAL ADU PLOTS WH

E R E A D U IS PO

does not satisfy

satisfies requirement

new (attached/detached) 48.7%

basement/attic carve out units per acre

63.9

gross sq ft per acre

54,843

ZONING

184

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

3F-2000 SemiAttached

1,000 sf

300 sf 300 per add’l

5 ft

2.5 ft

40 ft

20 ft

3F-2000 Other

2,000 sf (2 Units)

1,000 sf

300 per 1 300 per add’l

5 ft

2.5 ft

30 ft

20 ft

+1 +1 +1

+1 +1

+1 +1 +1

25 2 5

50 0

100 10 10 00

400 400 40 fee feet eet et et

neigborhood scale / east boston

POTENTIAL ADU LOCATIONS

186

accessory dwelling units

A1) Existing deck structure could potentially be converted but would be visible from the street. A2) The driveway provides a clear area where a small detached ADU could be placed. Constructing the ADU at the end of the driveway would reduce visibility.

A1 A2

A2 A1

A3) The basement provides another potential ADU location. Though visible from the street it would have minimal impact on the appearance of the existing building. B&C) Decks on buildings located away from the corner of a block provide possible ADU locations that are less visible.

A1) Existing screened-in porches can be insulated and expanded to allow for an ADU. The ADU could span multiple levels of the existing porch or carve out additional interior space from the existing apartment. A2) Existing rear decks can also be converted with addition of walls. Most rear decks and porches have limited visibility from the streets and neighboring properties. B) Car shelters, while lacking enclosure, can provide a starting point for ADU construction. Car shelters are normally visible from the street.

187

neigborhood scale / east boston

POTENTIAL ADU LOCATIONS

188

accessory dwelling units

A1) Existing structures located in the rear of parcels offer examples of the potential visibility of ADUs. A2) The driveway provides a clear area where a small detached ADU could be placed. Placing the ADU at the end of the driveway would reduce visibility. B) The Basement provides another potential ADU location. Though visible from the street it would have minimal impact on the appearance of the existing building.

A) Existing Rear Decks can also be converted with addition of walls. Most rear decks and porches have limited visibility from the streets and neighboring properties. B) Past Additions can more easily be separated from the host building and carve out an ADU. B A

189

neigborhood scale / east boston

POTENTIAL ADU LOCATIONS

190

accessory dwelling units

A1) Existing garage structures can be converted into ADUs. Garages are normally visible to the street. B) Driveways that are side by side are rare but allow pedestrians to see deeper into a block then they normally would. Wider driveways can also allow for new detached ADUâ&#x20AC;&#x2122;s to be placed on a site

C) Basements can provide an ADU location. Some basements may only be accessible through the rear of building due to site topography.

A B

A) Existing garage structures can be converted into an ADU . A1) Existing Overhead doors a can be removed and walled off, or be used to allow the ADU to open B) Larger driveways that wrap around buildings can provide an area for new ADU that is tucked behind an existing structure, minimizing visibility.

A A1 D

C B

C) Basement can be renovated with new layouts and utilities to create an ADU. A basement conversion would have minimal impact existing buildings.

191

neigborhood scale / east boston

POTENTIAL ADU LOCATIONS

192

accessory dwelling units

A1) Existing garage structures can be converted into ADUs. Garages are normally visible to the street. A2) Narrow driveways create larger areas of visual access than the typical fenced-off alleys. C

C B A1 A2

C) A dense street wall condition limits sight lines into the inner block. Privacy fences and plantings provide privacy with the block.

A) Existing garage structures can be converted into an ADU.

A1) Existing Overhead doors can be removed and walled off, or be used to allow the ADU to open.

A B

B) Converted decks may be visible in areas where there are driveways or other breaks in the street wall. Additionaly decks can see into neighboring yards and potential ADU locations.

A2 A3

A2) Some garage structures already have doorways for people, others only have a single overhead door. A3) A portion of the open space may be turned over to the ADU in order to increase appeal / value. B) Fences and planting areas can help limit the ADUs visibility C) Higher up neighbors will still be able to see ADUs 193

neigborhood scale / east boston

ADU SEPARATE SITE ENTRY

194

accessory dwelling units

A) Solid fences can block visual access to ADUs and associated elements. B) Access to the primary structures rear deck remains visible from the street while the front gate is closed, while ADU access is blocked by the fence.

B A

A) Ramps directly accessing rear decks provide an opportunity to split access into the site between the ADU and the primary structure. B) With entry to the primary structure access by a ramp to the rear deck, the rest of the side alley (side yard setbacks) can be dedicated to creating an entry condition for the an ADU. A B

195

neigborhood scale / east boston

POTENTIAL ADU SITE ENTRY

196

accessory dwelling units

197

neigborhood scale / east boston

TYPICAL BLOCK CONDITIONS A

198

accessory dwelling units

A) Typical Alleyway Entry

B) Gated Driveway

C) Sloped Driveway

D) Small Parks at Street Grid Intersections 199

neigborhood scale / east boston

ADDITIONAL EAST BOSTON SITE CONDITIONS Many blocks in East Boston have doorways as part of a solid wall assembly at the entrance to the side alleys. These doorways provide an extra degree of privacy and security for backyard access.

A) Some residences in East Boston do not have an entry facing the street wall. Instead they have entry(s) located along the side or rear of the building, B) ) Chain link fences provide a physical separation, but neighbors and passersby can still see into the yard. Privacy fences with gates are more common than chain link fences and offer a greater degree of privacy.

200

accessory dwelling units

A) Some residences in East Boston already have two entrances facing the street. One entrance is typically dedicated to a shared entrance for apartments on the first floor and above. B) The other is dedicated to basement access. Most basement accesses located on the street access basement level apartments, while others access storage space.

A) Existing garage structures can be converted into an ADU. B) Car shelters, while lacking the walls, can provide a starting point for ADU construction. Car shelters are normally visible from the street. A B

201

DORCHESTER Dorchester is a fairly dense neighbor hood, but it does allow some some space for ADUâ&#x20AC;&#x2122;s. Typical fabric prodominantly varies between largely homogenized triple deckers and unique two family houses with steeply pitched roofs. Challenges do in involve access, particularly in steeper areas where front yard retaining walls are common, but more have to do with zoning, as currently the area is drastically overbuilt.

202

neighborhood scale / dorchester

PARKING total parcels

driveways garages + sheds parcel boundaries parking boundaries units per acre

18.4

gross sq ft per acre

28,800

1.9 OFF S

parking per unit:

T EE TR

51%

total:

79 ON

EET TR

49%

total:

neighborhood scale / dorchester

YARD SETBACKS

365 sf

142 sf

unbuildable area buildable area

max

min

size of accessory unit (allowable, 25% rear setback)

average

241 sf

ZONING

206

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

neighborhood scale / dorchester

FLOOR AREA RATIOS

2F A

LY PARC AMI EL 1F

one family two family

43%

13%

PARCELS ILY M

three family four-six family

RCELS PA

37%

ER PARC OTH EL

3 FA M I

ZONING

208

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

.57

.51 .54 .57

.63 .57 .68

.76

.74

.49

.38 .36

.38

.46 .52

.72 .42

.52 .74 1.12

.52

.96

.97

.95

1.22 .65

.60

.84

1.12

.52

1.09 1.07

.64

1.07 1.01

.85 .84 .19

1.63 .86

.90

.98

.93

neighborhood scale / dorchester

UNUSED FAR PA RC

under FAR limit remaining FAR sf

VER FAR LEFTO ITH W S EL

over FAR limit 13%

at FAR limit

ZONING

210

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

-.07

-.07 -.04

-.07

-.13 -.07

-.18 -.24

673 sf

.14 1,739 sf

.12

805 sf

f 146 s

-.46

.08

-.62

382 sf

-.45

-.47

-.24

-.72 -.10

-.15 -.34

-.62 -.57

-.14

-.57 -.51 -.43

-.35

2,559 sf

-.26

.04 -.22

-.02

.12

-1.13 .31 -.36

-.34 -.40

-.48

-.59

neighborhood scale / dorchester

This scenario determines which parcels can accoomodate an ADU under current zoning regulations.

SCENARIO A - AS OF RIGHT satisfies requirement

USED BY ZONING DER UN

does not satisfy new (attached/detached) basement/attic

carve out units per acre

19.5

gross sq ft per acre

29,464

ZONING

212

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

neighborhood scale / dorchester

This scenario determines which parcels can accoomodate an ADU when Lot Area and Lot Area per Additional Unit are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

SCENARIO B - DISREGARD LOT AREA satisfies requirement does not satisfy

PARCE LS WH ER E

new (attached/detached) basement/attic carve out

SIBLE POS IS U AD

24%

units per acre

21.2

gross sq ft per acre

30,526

ZONING

214

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

+1 +1

+1 +1 +1 +2

+1 +1

neighborhood scale / dorchester

SCENARIO C - DISREGARD LOT AREA + FAR satisfies requirement

This scenario determines which parcels can accoomodate an ADU when Lot Area, Lot Area per Additional Unit, and FAR are disregarded. Adding an ADU to a parcel maxed at the unit limit is allowed.

does not satisfy PARCELS WH ER EA D

new (attached/detached) basement/attic carve out units per acre

23.5

gross sq ft per acre

31,854

BLE SSI PO

46%

ZONING

216

Lot Area (min)

Lot Area per Additional Unit

FAR (max)

Usable Open Space

Front Yard (min) Depth

Side Yard (min) Depth

Rear Yard (min) Depth

Lot Width

2F-5000

5,000 sf for 1 or 2 units

n/a

750 sf per unit

15 ft

10 ft

20 ft

40 ft

3F-5000

5,000 sf for up to 2 units

2,500 sf

750 sf per unit

15 ft

10 ft

20 ft

40 ft

+1 +1

+1 +1 +1

+1 +1 +1 +1

Side-yard access

Typ Fences: side vs back yards

Backyard Conditions

Driveway access

Garage Conversion Potential

COMMERCIAL DISTRICT INTERVENTION OPPORTUNITIES One-story commercial buildings are prevalent elements in many neighborhood main street areas, and offer excellent opportunities to pursue ADU development. Construction of additional units can occur in a variety of underutilized spaces- such as the unbuilt air rights above a building, or in rear parking lots and service zones. Integrating ADUs as part of a mixed use strategy can increase activity in these commercial districts, while shifting some development away from residential areas.

220

neighborhood scale / commercial district intervention opportunities

MAVERICK SQUARE - EAST BOSTON

222

A) Back alleys have both parking areas and green space

B) Back alleys are have existing rooftop access

C) Open spaces behind businesses can be developed

D) Parking lots behind businesses fill the backs of lots

EAST BOSTON I MAVERICK SQUARE

D A

223 23 23

neighborhood scale / commercial district intervention opportunities

DORCHESTER, BOWDOIN STREET

224

A) Alleys behind some businesses drop in elevation

B) Areas behind shops are used for trash collection

C) Parking lots behind businesses fill the backs of lots

D) Parking lots behind businesses fill the backs of lots

ac acc c e es ess ssor ss ory o rry yd dw w well elllllliin ell e in ing ng gu un nits itts it s

22 225 25 25

neighborhood scale / commercial district intervention opportunities

CENTRE STREET - JAMAICA PLAIN

226

neighborhood scale / commercial district intervention opportunities

HYDE PARK - RIVER STREET

228

acc ac a cc cess ess e es ss s sory o dw or dwe ellling el ng gu un nits ts s

2 9 22 229

BUILDING SCALE TYPOLOGIES BUILDING ORGANIZATION REGULATORY THRESHOLDS TYPOLOGICAL EXAMPLES STRUCTURE DESIGN OPPORTUNITIES

234 252 268 274 292 304

231

232

The purpose of this chapter is to scale all the way down to the individual building and building typologies that form the urban fabric of Boston. To reveal the architectural composition of the city, this chapter is divided into four sections which cover in-depth the two major housing building typologies that represent Boston; the urban three-family triple decker and the two family residence. Each type is studied in terms of typological families, form, construction, and real world examples. The analysis of this chapter is meant to serve as a deeper study of architectural forces and building code, as opposed to the focus on zoning code as in the prior

chapters. The goal is to understand Bostonâ&#x20AC;&#x2122;s current housing climate from the inside out, which in turn reveals Accessory Dwelling Unit design potentials. This section serves as a study and analysis of what is existing in Boston, and not specifi c design interventions. The analysis of general conditions of what is most prevalent around the city allows for later ease in selection of homes and properties to implement an ADU. Information presented is both overly generic to group types together revealing patterns and similarities in housing, and at the same time overly specifi c down to precise data and drawings of built properties. 233

TYPOLOGIES This section analyzes Bostonâ&#x20AC;&#x2122;s housing typologies in the five neighborhoods selected as prime conditions for implementing Accessory Dwelling Units - Jamaica Plain, Hyde Park, Dorchester, West Roxbury, and East Boston. The following pages will chart and define patterns in two-family, three-family, and six-family homes. By analyzing general patterns in Bostonâ&#x20AC;&#x2122;s housing typologies, it will be easier to select homes that are ideal for hosting an Accessory Dwelling Unit. For instance, a certain typology may be oversized, it may have a stair set-up that allows for easy ADU access, or it may have unused basement or attic space. This study will make it possible to view the exterior of a home, rapidly make an accurate guess as to the interior configurations, and to imagine how an ADU could potentially fit within it.

234

architectural scale / typologies

TWO FAMILY TYPOLOGY Boston’s two family units are the most diverse of the family types. While there is not a clear typical two family home in Boston, it is the most numerous multifamily housing type in three of the five neighborhoods studied (Jamaica Plain, West Roxbury, and Hyde Park). Most of Boston’s two-family homes are owner-occupied. Typically, the owner will live in one floor and rent out the other, although condominium situations are also common. The most common two-family house is a 2.5 story dwelling with a gable roof. The front door and entry stair is on the side, and the second stair is in the rear corner. Usually, the owner will rent the first floor and live in the top 1.5 stories.

25%

24% 29% 12% 23%

Percentage of two-family housing units out of neighborhood’s total housing. 236

accessory dwelling units

CONFIGURATIONS

DOORS

STAIRS

FLOORS

237

architectural scale / typologies

MODERN BUNGALOW Square Feet: 2000-3000 sf Dimensions: approx. 30’x50’ Built: 1970-1990 Neighborhoods: Hyde Park, West Roxbury Style: Craftsman Common Variations: no stair in front, porch in back BRICK

DUPLEX STANDARD Square Feet: 1500-2500 sf Dimensions: approx. 45’x30’ Built: 1900-1920 Neighborhoods: West Roxbury, Jamaica Plain, East Boston Style: Victorian Common Variations: bay windows on front or side, dormers, front porch

238

accessory dwelling units

TWO PACK DOUBLE Square Feet: 2000-3000 sf Dimensions: approx. 30’x55’ Built: 1900-1930 Neighborhoods: Hyde Park, Dorchester, East Boston, Jamaica Plain, West Roxbury Style: Colonial Common Variations: back porch, side porch, dormers, bay window in front

TWO PACK TOP DOUBLE Square Feet: 2000-3000 sf Dimensions: approx. 40’x50’ Built: 1910-1920 Neighborhoods: Hyde Park, West Roxbury, Jamaica Plain Style: Colonial Common Variations: front porch, back porch, bay windows on side, no dormers, additional dormers

239

architectural scale / typologies

TWO PACK SIDE Square Feet: 1000-2500 sf Dimensions: approx. 30’x60’ Built: 1860-1900 Neighborhoods: Hyde Park, Jamaica Plain Style: Colonial Common Variations: side porch, bay windows, door recessed but facing street

TWO PACK TOP Square Feet: 1500-2500 sf Dimensions: approx. 35’x40’ Built: 1910-1920 Neighborhoods: Hyde Park, West Roxbury, Jamaica Plain, Dorchester Style: Colonial Common Variations: front porch, back porch, bay windows, no dormers or additional windows

240

accessory dwelling units

THREE PACK MINI Square Feet: 1500-2500 sf Dimensions: approx. 25’x50’ Built: 1880-1910 Neighborhoods: East Boston, Jamaica Plain, Dorchester Style: Victorian Common Variations: zero lot line configurations, extra floors, front or back porch, additional bay window

TWO PACK STANDARD

*most common typology Square Feet: 1500-2500 sf Dimensions: approx. 30’x50’ Built: 1890-1920 Neighborhoods: Hyde Park, West Roxbury, Jamaica Plain, Dorchester, East Boston Style: Colonial Common Variations: front porch, back porch, bay windows, dormers

CLAPBOARD BOTTOM

241

architectural scale / typologies

THREE FAMILY TYPOLOGY The three family typology is the most common multifamily housing typology in Boston. It is the most common in two of the five neighborhoods studied, East Boston and Dorchester. Three family homes are also the most common housing type in all of Boston. Three family homes are much less likely to be owner-occupied than two family homes, but it is not unusual. Typically, the owner will live in the top one or two floors and rent out the bottom floor. Certainly the most popular three family home is the iconic triple decker, to be analyzed in further detail towards the end of this section.

43%

23% 31% 1% 4% Percentage of three-family housing units out of neighborhoodâ&#x20AC;&#x2122;s total housing. 242

accessory dwelling units

CONFIGURATIONS

DOORS

STAIRS

FLOORS

architectural scale / typologies

TWO PACK MID CENTURY Square Feet: 2000-2500 sf Dimensions: approx. 35’x50’ Built: 1950-1960 Neighborhoods: Hyde Park Style: Craftsman Common Variations: elevated front door, back porch

THREE PACK SPLIT LEVEL Square Feet: 3000-4000 sf Dimensions: approx. 35’x70’ Built: 1910-1925 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain Style: Victorian Common Variations: back porch, bay window on side elevation, front porch CLAPBOARD FACADE

244

accessory dwelling units

COLONIAL DOUBLE Square Feet: 2500-3500 sf Dimensions: approx. 50’x40’ Built: 1910-1925 Neighborhoods: Hyde Park Style: Colonial Common Variations: additional dormers, back porch

THREE PACK DOUBLE Square Feet: 3500-5500 sf Dimensions: approx. 40’x55’ Built: 1900-1910 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain, East Boston Style: Victorian Common Variations: back porch, bay window on side elevation, front porch, attic

245

architectural scale / typologies

SIX PACK THREE PACK Square Feet: 3500-5000 sf Dimensions: approx. 50’x55’ Built: 1900-1915 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain Style: Victorian Common Variations: flat front, back porch, side porch, front porch, bay window on side

SIX PACK MINI Square Feet: 3500-4500 sf Dimensions: approx. 35’x55’ Built: 1900-1910 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain Style: Victorian Common Variations: back porch, front porch, bay window on side, additional dormers

246

accessory dwelling units

TRIPLE DECKER STANDARD

*most common typology 7B both egress stairs adjacent Square Feet: 2000-4500 sf Dimensions: approx. 30’x70’ Built: 1900-1910 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain, East Boston Style: Victorian Common Variations: flat front, front porch, back porch, bay windows on side, attic

THREE PACK ROUND Square Feet: 3000-4000 sf Dimensions: approx. 40’x60’ Built: 1900-1910 Neighborhoods: Dorchester, Jamaica Plain Style: Victorian Common Variations: back porch, front porch, bay window on side, additional dormers, additional bay window on front

247

architectural scale / typologies

TWO PACK CURVE TOP Square Feet: 2500-3000 sf Dimensions: approx. 35’x50’ Built: 1900-1910 Neighborhoods: Hyde Park Style: Victorian Common Variations: back porch, additional dormers

TWO PACK THREE PACK Square Feet: 2500-3000 sf Dimensions: approx. 35’x70’ Built: 1900-1910 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain Style: Colonial Common Variations: front porch, back porch, bay windows on side, no dormers or additional dormers

248

accessory dwelling units

THE TRIPLE DECKER Boston’s most iconic housing type is the triple decker. Boston has more triple deckers by population than any other city in the world, and many neighborhoods in Boston are housed largely by triple deckers. The triple decker first began appearing in Boston in the 1870’s. It was based on the construction of three-decker ships and was believed to be the most efficient layout in Boston’s long and narrow lots. Triple deckers quickly became popular in Boston and throughout New England because they were seen as an easy and economical means of housing the growing working class. One family would typically own the triple decker, live in one or two units and rent out the other. Although they were designed for the working class, the middle class quickly took a liking to them as well, and often built more ornate versions as single-family homes. Triple deckers traditionally feature the living room in the front, the kitchen in the back, and bedrooms and bathrooms in the middle. One stair is placed at the front entry, and the other is usually at the back, often accompanied by a back porch. Most triple deckers had two or three bedrooms and one bathroom. It’s likely that most of Boston’s triple deckers are “balloonframe” construction. Today, there are very few triple deckers that have not been substantially renovated. In an attempt to add an extra bedroom, many renovations have converted the dining room into an extra bedroom. In other cases, the floors have been entirely gutted to create a modern and open floor plan.

Original triple-decker floor plans

Boston triple-deckers in 1905 249

architectural scale / typologies

SIX FAMILY TYPOLOGY Boston’s six family buildings often look very similar to the standard triple decker. The “six pack” typology is simply a triple decker with two, rather than one, units per floor. Each unit occupies half of a floor plate and spans from the front to back of the building. In the typical six pack, the entry and stair is centered in the middle of the floor plate. The second stair is centered at the back. The living room is typically at the front, the kitchen at the back, and bedrooms and bathrooms occupy the middle. Six family homes are rarely owneroccupied. They are also the least common family type in the neighborhoods shown below.

6 CONFIGURATIONS

DOORS

STAIRS

2% 1% 1% FLOORS

1% Percentage of six-family housing units out of neighborhood’s total housing.

250

accessory dwelling units

SIX PACK DOUBLE Square Feet: 8000-9000 sf Dimensions: approx. 45’x90’ Built: 1910-1925 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain, East Boston Style: Colonial Common Variations: back porch, bay window on side or front

SIX PACK STANDARD Square Feet: 3000-5500 sf Dimensions: approx. 40’x70’ Built: 1900-1925 Neighborhoods: Hyde Park, Dorchester, Jamaica Plain, East Boston Style: Victorian Common Variations: back porch, front porch, bay window on side, attic, flat front

251

BUILDING ORGANIZATION Creation of new accessory dwelling units carries a variety of implications for existing structures. Almost any modification work has the potential to affect spatial, circulation, sanitary, or life safety systems. Before construction of new ADUs can begin, it is important to first understand the frameowrk within which new dwelling units must be integrated. Careful neogtiation of existing unit layouts and spatial logics will be a necessary.

252

architectural Scale / building organization

BUILDING ELEMENTS - THREE FAMILY

Attic Second Floor Circulation zone First Floor Circulation Zone Ground Floor Shared Circulation Zone Front Porch / Shared Entry Front Yard (if any)

Front View

254

Units Bedroom Zone Units Living Area Zone Side Yard (if any)

accessory dwelling units

The Three Family, commonly a formulation of the Triple Decker-is a mainstay in Bostonâ&#x20AC;&#x2122;s housing stock. Characterized by narrow profiles and deep lots- these buildings are densely clustered in various neighborhoods throughout the city. Porches and decks are often integrated as a part of common building entries and egress. Front and rear yards act as buffers between the public way and neighborhing buildings. Frequently, side yards are used as driveways or for rear yard access when there is sufficient space between adjacent buildings. The building front is composed of protrusions into the parcel front yard. An exterior porch will act as a transition between grade and building entry. Bays provide valuable added square footage while enhancing access to natural light. Dense window placement reflects internal unit program, with living or bedroom spaces generally located in this zone.

255

architectural Scale / building organization

BUILDING ELEMENTS - THREE FAMILY

Attic

Front Porch / Shared Entry

Second Floor Shared Circulation zone First Floor Shared Circulation Zone Ground Floor Shared Circulation Zone Back Porch / Shared Entry Rear Yard Rear View

256

Units Bathroom Zone Units Bedroom Zone Side Yard (if any)

accessory dwelling units

Sidewalls are less likely to feature protruding elements such as bays or porches. Sideyards that would offer enough space for these elements are instead utilized for driveways or walkways providing parking and rear yard access. Windows for bathrooms and bedrooms, in addition to plumbing and ventilation outlets are positioned along sidewalls. Rear walls are defined by porches, either with one shared porch at ground level or vertically stacked decks serving each unit. Common building egress is accessed at the groud floor porch, and connects to each unit and deck. Rear yards offer valuable amenity space- either in the form of offstreet parking or green space. Common use garbage and recycling bins are frequently stored in these rear yards, and growing numbers of renovated buildings will have central air conditioning units positioned here as well.

257

architectural Scale / building organization

INTERIOR SYSTEMS - THREE FAMILY Front View Shared Attic Access

Attic Circulation

Unit 2 Entry Access Shared Building Circulation Zone

Unit 1 Entry Access From Entry Foyer Shared Entry Foyer

Main Circulation, Scheme One In this layout, units are arranged off of a common stair. Because every floor contains an individual unit entrance, landing space is shared. While this allows building-wide access to vertical circulation at each level, it also decreases usable square footage for each unit. 258

accessory dwelling units

Front View Unit 3 Attic Access Unit 3 Interior Circulation

Unit 2 Entry Access

Unit 3 Entry Access

Shared Circulation Zone Shared Circulation to First Floor Floor

Shared Entry Foyer

Main Circulation, Scheme Two In this scheme, the shared stair terminates at the first floor landing, where entry doors for units 2 and 3 are located. While this increases usable floor space for units 2 and 3, it also eliminates common access to the attic. 259

architectural Scale / building organization

INTERIOR SYSTEMS - THREE FAMILY Rear View

Shared Attic Access

Shared Attic Circulation Shared Circulation Zone

Shared Stair Vestibule from Rear Deck

Rear Egress, Scheme One The rear stair is normally much tighter than the main circulation at the building front. It is integrated with unit exterior decks, a shared ground floor vestibule and porch and provides access to the parcel rear yard. 260

accessory dwelling units

Program / Spatial Disposition Apartments are arranged with habitable spaces anchored to long hallways, which provide a direct connection to multiple means of egress. Living areas occupy zones of the building with the most access to daylighting and ventilation. Bedrooms are placed along side and rear walls, while bathrooms are often found adjacent to stairwells. 261

architectural Scale / building organization

BUILDING ELEMENTS - TWO FAMILY Front View

Attic / Bedroom Living Area Zone

Rear Yard

Circulation Zone Units Bedroom Zone Individual Entries to Circulation Zone

Units Bathroom Zone

Shared Front Porch Front Yard (If any)

262

Side Yard (if any)

accessory dwelling units

The Two Family type has many of the same exterior elements of the larger Three Family. Narrow profiles and deep lots are characteristic, and many two families can be found in neighborhoods similar to their three family counterparts. Porches and decks are often integrated as a part of common building entries and egress. Front and rear yards act as buffers between the public way and other buildings. Frequently, side yards are used as driveways or for rear yard access when there is sufficient space. The building front is defined by protrusions into the parcelâ&#x20AC;&#x2122;s front yard, as illustrated above. An exterior porch acts as a transition between circulation at grade and building entry. Bays provide valuable added square footage and enhance access to natural light. Dense window placement reflects internal unit program layouts-with living spaces almost exclusively located in this zone.

263

architectural Scale / building organization

BUILDING ELEMENTS - TWO FAMILY Rear View

Attic / Bedrooms

Circulation Zone Second Floor

Units Living Area Front Zone

Circulation Zone First Floor

Units Living Area Rear Zone

Shared Back Porch / Entry

Side Yard (if any)

Rear Yard

264

accessory dwelling units

265

architectural Scale / building organization

INTERIOR SYSTEMS- TWO FAMILY Front View

Unit 2 Interior Stair to Attic Unit 2 Access

Circulation Zone

Individual Entries to Circulation Zone Shared Front Porch

accessory dwelling units

Program / Spatial Disposition As opposed to the Three Family Typology, the Two Family relies less on the long hallway circulation strategy, with fewer rooms per floor. Living area zones occupy significant portions of both the front and rear facades. Vertical circulation occupies zones similar to those of the Three Family. 267

REGULATORY THRESHOLDS ADU construction will often trigger additional work that is required to bring existing buildings up to code. The specifics of this compliance are often proportional to the intensity of renovation work being carried out. In Massachusetts, the stateâ&#x20AC;&#x2122;s building and accessibility codes govern the applicable regulatory standards that must be satisfied when creating dwelling units. Understanding the various thresholds that dictate this compliance is critical to the ADU design process.

268

architectural Scale / regulatory thresholds

DEFINITIONS / CATEGORIES Massachusetts Building Code is comprised of two distinct codes- the 2009 International Building Code and the 2009 International Residential Code. The former sets standards for any building with more than two dwelling units, while the latter governs one and two family dwellings. Each has its own set of definitions, thresholds, and compliance factors. The creation of ADUs within existing buildings will trigger a varriety of additional regulatory compliance work. Upgrades to fire protection, structural, and egress systems are entirely dependent on several factors. First, the amount of work being performed, usually measured in square footage as a proportion of the total building area. These are categorized as Level 1, 2, or 3 alterations. The occupancy and category type of the building itself will affect the level of additional work required to bring a building and ADU up to code. As illustrated above- much of the existing housing stock that our research is based on will fall into two categories. Type R-2 construction is categorized as Residential occupancy with three or more dwelling units. Type R-3 Occupancy is composed of Residential occupancy with two or less dwelling units. Besides quantifying the amount of dwelling units in a building, Type R-2 generally requires a higher level of intensity of code compliance work.

270

UNIT 3 UNIT 2

UNIT 1 TYPE R-2

UNIT 2 UNIT 1 TYPE R-3

accessory dwelling units

Level 2 alterations are defined as scope of work being less than 50% of the total building footprint. This requirement means that the total work involved in regorgnization or spaces, egress circulation, and new ADU construction must be under this threshold. If the work comprises more than 50% of the building footprint, it is qualified instead as a Level 3 alterationwhich contains additional requirements for meeting building and fire code. Illustrated on the right are the boundaries associated with a Level 2 alteration in both a two and three family building. However, it should be noted that many provisions of the Existing Building Code require greater levels of code compliance when work exceeds 50% of any single floor.

WORK BOUNDARY STAIRWAY SPATIAL

TYPE R-2

Building 1 : 3,850 sq. ft. Work can be conducted throughout an entire floor of the building, in addition to one means of shared egress. This work is equal to 1,900 sq. ft. of alterations. Building 2 : 2,070 sq. ft. Here again, work can be conducted throughout an entire floor of the building, in addition to one means of shared egress. This work shown is equal to 1,035 sq. ft.

TYPE R-3

271

architectural scale/ regulatory thresholds

WORK AREA TRIGGERS In addition to building-wide thresholds, code compliance is triggered at an individual floor level. Often when a work area exceeds 50% of any one floor, added requirements are put in place that will increase the necessary amount of construction. This in turn will add layers of complexity to both financing and project timelines- an undesirable outcome. A careful balancing of realistic construction methods while staying within code thresholds is necessary in design strategies.

WORK BOUNDARY STAIRWAY SPATIAL

Building 1 Floorplate : 1,065 sq. ft. Work can be conducted in an entire bedroom, a majority of a second bedroom, the shared hallway and one form of egress. This work is equal to 530 sq. ft. of alterations.

TYPE R-2

Building 2 Floorplate : 850 sq. ft. Work is performed within an entire bedroom, a portion of the kitchen, and one form of vertical egress. This work shown is equal to 425 sq. ft.

272

TYPE R-3

accessory dwelling units

Life safety systems have varying levels of distribution and installation, depending on the amount of work being performed in a given area. In some instances, any work in an area triggers these requirements. Other times, work must reach certain thresholds before triggering wider instances of efforts.

Approximate Work Trigger Any Amount of Work Work Area Totals 50% of Floor No Work Triggered Provisions

273

TYPOLOGICAL EXAMPLES Throughout the city of Boston, patterns in housing type can be clearly seen street to street, neighborhood to neighborhood. This sections shows real examples of two of the most prevalent housing types in Boston, the triple-decker and the two-family, in order to reveal patterns and similarities throughout each type. These real world examples are current as-built properties around the city.

274

architectural scale / typological examples

B.R.A. DEFINED TYPICAL TRIPLE-DECKER

Typical Floor Plan Unit Two 3/32” = 1’0”

Triple Decker Type 7 : Triple Decker Standard

Net Area Gross Area Lot Size

Building 276

3,261 sf

3,729 sf

FAR

Floors

Occupancy Parking -

Built -

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Third Floor Plan Unit Three 1/32” = 1’0” 277

architectural scale / typological examples

B.R.A. DEFINED TYPICAL TRIPLE-DECKER

Typical Floor Plan Unit Two 3/32” = 1’0”

Triple Decker Type 5 : Six Pack Three Pack Net Area Gross Area Lot Size Building 278

4,290 sf

4,524 sf

FAR

Floors

Occupancy Parking -

Built -

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Third Floor Plan Unit Three 1/32” = 1’0” 279

architectural scale / typological examples

820 PARKER STREET TRIPLE-DECKER

Typical Floor Plan Unit Two 3/32” = 1’0”

Triple Decker Type 4 : Three Pack Double Building

280

Net Area

Gross Area

Lot Size

FAR

5,509 sf

6,251 sf

4,862 sf

1.28

Type

Occupancy

Parking

Built

Renter

Off Street

1950

accessory dwelling units

Basement Floor Plan Unit One 1/32” = 1’0”

Ground Floor Plan Unit One 1/32” = 1’0” Building Section - 1/16” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Third Floor Plan Unit Three 1/32” = 1’0” 281

arcitectural scale / typological examples

32 LAWN STREET TRIPLE-DECKER

Typical Floor Plan Unit Two 3/32” = 1’0”

Triple Decker Type 7 : Triple Decker Standard Net Area Gross Area Lot Size Building 282

3,536 sf

3,872 sf

3,142 sf

FAR 1.23

Type

Occupancy Parking Renter

Off Street

Built 1950

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Third Floor Plan Unit Three 1/32” = 1’0” 283

architectural scale / typological examples

8 OSWALD STREET TRIPLE-DECKER

Typical Floor Plan Unit One 3/32” = 1’0”

Triple Decker Type 7 : Triple Decker Standard Net Area Gross Area Lot Size Building 284

3,636 sf

4,390 sf

3,240 sf

FAR

Floors

1.35

Occupancy Parking Renter

Off Street

Built 1890

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Third Floor Plan Unit Three 1/32” = 1’0”

Attic Floor Plan Unit Three 1/32” = 1’0” 285

architectural scale / typological examples

33 PRATT STREET TWO-FAMILY

Typical Floor Plan Second Floor 3/32” = 1’0”

Two Family Type 8 : Two Pack Standard Net Area Gross Area Lot Size Building 286

2,969 sf

3,155 sf

4,862 sf

FAR

Floors

.65

Occupancy Parking Renter

Off Street

Built 1920

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Attic Floor Plan Unit Two 1/32” = 1’0” 287

architectural scale / typological examples

108 SCHOOL STREET TWO-FAMILY

Two Family Type 2 : Duplex Standard 288

Net Area Gross Area Lot Size Building

3,907 sf

4,501 sf

4,131 sf

FAR

Floors

1.09

Occupancy Parking Renter

Off Street

Built 1885

accessory dwelling units

Ground Floor Plan Units One & Two 1/32” = 1’0”

Building Section - 1/16” = 1’0”

Second Floor Plan Units One & Two 1/32” = 1’0”

Third Floor Plan Units One & Two 1/32” = 1’0” 289

architectural scale / typological examples

136 COLERIDGE STREET TWO-FAMILY

Typical Floor Plan Second Floor 3/32” = 1’0”

Two Family Type 7 : Three Pack Mini Net Area Gross Area Lot Size Building 290

1,344 sf

1,532 sf

1,875 sf

FAR

Floors

.82

Occupancy Parking Renter

Street

Built 1910

accessory dwelling units

Ground Floor Plan Unit One 1/32” = 1’0”

Second Floor Plan Unit Two 1/32” = 1’0”

Building Section - 1/16” = 1’0”

291

STRUCTURE This chapter explores the most common system of framing and structure for multi-family homes in Boston: the balloon frame. Though every building has its individual quirks and renovations, the balloon frame system drove much of the light weight wood construction in the 20th and late 19th centuries.

292

building scale / structure

PLATFORM vs. BALLOON FRAMING with platform framing. This is because walls can be fabricated down on the floor. The technique also requires less labor. This helps to keep construction costs within reasonable limits.

Disadvantages Structural problems may occur after completion of the house. This is because the joists and headers experience interruption from the sub-floor. Vertical shrinkage is likely when the wood dries. This may destabilize siding materials, resulting in frequent maintenance.

Platform Framing Advantages It is a simpler construction process compared to balloon construction. The technique involved also makes it a quicker method of construction. One structure is constructed and is well supported by a foundation. Builders then use the first level as a platform to project the next floor. The process continues until the desired number of floors is achieved. Rafters and roof joists are erected on the final tier of walls. Platform framing utilizes less wood. Additionally, smaller pieces of wood can be used on the wall frames. No fire stopping is necessary because the stud spaces are enclosed by the floor platforms. The safety level for workers is higher 294

accessory dwelling units

Balloon Framing Advantages Fewer problems are expected once construction is complete. Drywall cracking is unlikely. This adds to the durability of the building. Balloon construction is useful where a vaulted ceiling or two-story open foyer is desirable. Where a tall chimney is preferred, the balloon technique is also useful. With balloon framing, you get more flexibility in window design. Angled or arched window tops are easier to achieve. Large or vaulted windows are also more workable with the balloon technique than platform framing. The technique creates a higher resilience structure due to the longer wall frames used. The building is better able to withstand high speed or gusty winds.

Disadvantages In the event of a fire, the building is likely to be destroyed more quickly. This is because the structure provides an easy path for fire to travel from one floor to the next. It becomes necessary to install fire stops on each level. Balloon framed buildings donâ&#x20AC;&#x2122;t have insulation between a room and its exterior walls. This contributes to increased energy utilization, hence higher costs. Additionally, the long framing members used in construction pushes up construction costs. Walls constructed turn out to be very heavy. To raise these walls, more labor, skill and specialized equipment is required. It also increases the risk during work. 295

building scale / structure

20’ - 1”

24” o.c. 6 x 6 girder

6’ - 6”

16’

Floor joists face nailed to vertical studs

Ground Floor 296

24” o.c.

16’ - 9”

15’ - 7”

10’

entrance

Three-deckers were most commonly built in the emerging industrial cities of the New England region of the United States between 1870 and 1920. They were primarily housing for the working-class and middle-class families, often in multiple rows on narrow lots in the areas surrounding the factories. It is estimated that by 1920, the city of Boston had over 15,000 triple decker houses. Areas such as Dorchester, Roxbury, Mattapan and Jamaica Plain were popular with the emerging middle class. Typically, the affordable triple decker homes attracted live-in landlords who would collect rent from the other two apartments.

6 x 6 post

Area: 5,072 ft2 Volume: 45,840 ft3

building entrance

non-structural interior walls sit on subflooring

TRIPLE DECKER FRAMING

accessory dwelling units 3’ - 6”

7’ - 7”

3’ - 6”

8’ - 5”

roof peak 3’ - 8”

primary stairwell

roof plane change

15’

57’

53’ - 4”

bathroom

14’ - 7”

dormer

entrance

kitchen

dormer

15’

living

8’ - 5”

15’

bedroom

Upper Floors

secondary stairwell

8’ - 4”

bedroom

23’ Attic Space

Roof 297

building scale / structure

53’

13’

5’ - 6”

’

3’ - 6”

5’ - 6”

4’

7’ - 6”

ground floor

4’ - 6”

foundation diagonal cross bracing

298

accessory dwelling units 53’

20’ attic floor

’

header sill plate

third floor

windows stacked to eliminate excess studs

2’ - 6” 4’ 6’ - 6” 4’ 3’

second floor

299

building scale / structure upper ground floor floor enentrance trance

TWO FAMILY FRAMING

42â&#x20AC;&#x2122;

Two-flat - a building basically like a house, commonly built on a house lot, consisting of a flat (apartment) taking up the first floor, another flat taking up the second floor, usually a common basement, a common front entrance, foyer, and stairs to the second floor, and often a similar back entrance, foyer, and stairs. In old buildings, the back entrance, foyer, and stairs may have been added on later. Sometimes there are front verandas for each of flats, one above the other. Typically the whole building is owned by the same party. A property of this type, must have an external entrance for each unit.

24â&#x20AC;? o.c. typ.

Area: 2,223 ft2 Volume: 54,470 ft3

Ground Floor 300

accessory dwelling units 11’ - 9”

roof peak 4’ - 6”

5’ - 3”

4’ - 6” 2’

20’ 11”

entrance

10’ 6”

primary stairwell

living 14’ - 3”

42’

8’ - 4”

bedroom

kitchen

secondary stairwell

8’

15’ - 9”

bathroom

16’

44’

8’ 6”

11’ - 9”

26’ Upper Floors

Roof 301

33’ - 5”

1’ - 2”

9’ - 6”

10’ - 6”

8”

11”

8’ - 9”

302

31 36

4’ - 8”

4’

building scale / structure

accessory dwelling units

14’ - 9”

16’ 11”

3’ - 1” 2’ - 6” 3’ - 6” 3’ - 6”

3’ 4’ 2’ - 6”

7’

303

DESIGN OPPURTUNITIES This chapter will look at three potential oppurtunities for adding an accessory dwelling unit to an existing triple decker. These studies are not meant to be understood as a design proposal, but rather a showcase for potential oppurtunities.

304

building scale / design oppurtunities

ATTIC CONVERSION Area: 682 ft2 Volume: 5,455 ft3 Converting the existing attic storage into a 4th unit would require minimal if any additional framing. It is already provided with two means of egress; however the issue of head height arises. Only part of the attic may be considered viable living space.

7’

9’ - 5”

6’ - 6”

306

accessory dwelling units

9’

6’ - 6”

19’ - 9”

14’ - 6”

7’ - 2”

10’ - 2”

18’ - 6”

19’ 6’ - 6”

6’ - 6”

14’ - 6”

19’ - 9”

307

building scale / design oppurtunities

FIRST FLOOR REARRANGEMENT Area: 314 ft2 Volume: 2,825 ft3 Adding a unit to the ground floor only allows more flexibility in meeting egress requirements. The new unit wraps around the back stair as to not interrupt the existing building’s upper floor egress paths. It also allows for sharing a wet wall with the bathroom of the first floor apartment.

22’ - 6”

16’ - 8”

9’ - 8”

9’ 7’

308

13’ - 6”

accessory dwelling units

309

building scale / design oppurtunities

BEDROOM BLOWOUT Area: 648 ft2 Volume: 9,648 ft3 13’ - 6”

13’ - 6”

By utilizing the basement and higher ceilings, we can replace the bedrooms along the southwest corner with a 3-4 story townhouse with an entrance at grade or by tapping in to the back staircase. By keeping the bathroom and kitchen equipment as low in the unit as possible it minimizes costly plumbing and MEP changes.

310

5’ - 3”

build out to main girder to maximize potential space

12’ - 6” 12’ - 6”

38’ - 6”

7’ - 6”

fire rated wall separates units

accessory dwelling units

16’

13’ - 6”

Upper Floors

16” 16”

Ground Floor 311

CONSTRUCTION DETERMINANTS FOUNDATIONS 320 UTILITIES 334 FRAMING 346

313

314

Naturally, densifying a pre-developed area is fraught with unique and challenging conditions that make logistic determinants especially poignant in ADU construction. Often, the ADU mentality specifically targets sites with restricted access or poor working conditions, seeking to leverage this otherwise overlooked potential through their inherently lighter footprint. Likewise, when pursuing development on such a comparatively small scale, cost becomes increasing significant, and careful consideration of factors that may be taken for granted in larger projects is required to offset the scaled returns. When taken together, these two factors may

preclude many of the more conventional logics governing construction issues. Fortunately, ADUâ&#x20AC;&#x2122;s small size also affords them a degree of flexibility, and they are well poised to take advantage of innovative solutions developed to reduce the impact of these determinants. Three categories in which these solutions can be considered are the grounding and foundations in additions and new construction, running utilities connecting a unit to the necessary amenities, and framing and above grade construction. 315

construction determinants / introduction

SITE RESTRICTIONS

site obstacles

There are many factors that have to be taken into consideration when constructing an additional dwelling unit in an existing backyard. There are multiple site obstacles as well as site access and site topography that must be taken into consideration. All of these factors can help inform a decision about which construction method is best. Site obstacles include powerlines, fences or walls, and stairs or retaining walls. The use of crane, truck or man power are decisions that can be determined based on these site obstacles. How the site is accessed is a huge factor. The larger the site access, the more equipment can be brought in. 316

accessory dwelling units

site access

10’

site topography

semi trucks & heavy equipment

6’

10°

20° small equipment & manual equipment

0’

30° man power

317

construction determinants / introduction

ESTIMATED EXPENSES Considerations for Different Types of Framing:

There are many factors that go into the cost of construction for an additional dwelling unit. There is also the potentional for income and increased property value to take into considertion when constructing an accessory dwelling unit. Additionally, exploring the potential cost impact of an accessory dwelling unit is important because it will have an affect on the resale value of the property. While there might be some concerns about financing money for an additional dwelling unit the cost advantages have the opportunity to become more substantial when fully assessed. Accessory dwelling units increase the number of people per household while reducing the need, therefore the cost, to extend utilities and services. Accessory dwelling units can also benefit local businesses as well as attract new business to the community. The San Francisco ADU guidebook gave information on multiple types of accessory dwelling units and gave an estimated cost based on one typical prototype. This guidebook is a helfpul tool for furhter investigation into additional dwelling units in Boston. Provided is a cost estimate for a standard additional dwelling unit in San Francisco in comparison to Boston. 318

New Construction : excavation, cleanup Renovations : demolition, hidden costs, relocation costs Self Sufficient Prefab : reduced construction waste, cost of crane / truck Parasitic Prefab : reduced construction waste, cost of crane/truck Kit of Parts Prefab : reduced construction waste San Francisco - Assumed Scope of Work: • Construction of a fire-rated wall between the garage and the new unit, along with a vestibule and door(s) • Addition of windows and doors to serve the new unit • Construction of interior partitions in the new unit • A new bathroom and kitchen • Plumbing, heating and ventilation to serve the new unit. • Finishes and insulation at the new unit • Addition of sprinklers to the ground floor Additional Expenses (not included in cost): • Excavation and foundation work • Changes to the facade • Sprinklers and fire protection

accessory dwelling units

In San Franciscoâ&#x20AC;&#x2122;s guide to ADUs provides different prototypes. The costs shown to the right have come from estimates based on existing ADUs as well as an external site called New Avenue Homes. The costs are based on a prototype of a 675 sf garage conversion of a duplex building. This prototype is one of the most common in San Francisco, however the prices listed are pretty close to other ADU construction prices.

COST ESTIMATE

SAN FRANCISCO

BOSTON

Construction Costs Site work/ prep, earthwork and cleanup $12,300 Demolition $9,500 Shoring $2,000 Concrete $9,200 Framing and carpentry $14,700 Insulation and moisture protection $7,500 Windows and doors $11,700 Finishes $26,000 Plumbing (including fixtures) $21,000 Sprinklers $5,000 Heating and ventilation $6,300 Electrical (fixtures & appliances) $18,500 Overhead and profit $23,600 Sub-Total $167,300

$6,843 $0 $23,822 $2,769 $3,145 $30,705 $7,887 $11,630 $7,274 $103,226

City Permit Costs

For the Boston cost estimate, the numbers were based off of the book National Building Cost Manual. This cost estimate is not necessarily an accessory dwelling unit but a standard 600 sf new construction residential building.

Pre-application meeting fee San Francisco Building Permit fee School District Development fee (residential properties over 499 SF) Department of Public Works fee (sidewalk improvement, min. fee) Sub-Total Professional Services

$1,964 $1,228 $9,592 $3,849 .

Architectural & Engineering (approx. 10% of Construction Costs) TOTAL COST ESTIMATE

$600 $5,800 $3,849

$193,622

$16,730 $11,036 $118,111

319

FOUNDATIONS As inaccessibility is often a defining factor in ADU determination, the conventional approach to grounding and itsâ&#x20AC;&#x2122; associated excavation may not be a well suited option, and the smaller, light-weight potential of these constructions may make them conducive to alternative solutions. There are a number of products that, while perhaps predominantly targeted for lighter weight applications like porches or sheds, have seen great success in small buildings. Similarly, innovative approaches to the implementation of a poured foundation can significantly reduce excavation and concrete volume, or allow for smaller, more flexible equipment to be used.

320

http://tomtarrant.com/tag/room-additions/

construction determinants / foundations

Note:

For the purpose of direct comparison, foundation parametrics have been calculated in this section according to these standards.

Building Size: 240sqft 20â&#x20AC;&#x2122;

1 Story @ 60 lb/sqft: 14,400lb

3,000 lb/sqft Soil Bearing Capacity

322

12â&#x20AC;&#x2122;

well suited

Invasive Long Install Expensive Light-Weight

conditionally suited

Monolithic

poorly suited

Low Impact Quick Install Inexpensive Robust

Fl ex Gr ible ad A e bo Co v ns e In ac tru ce ct ss io n ib Po l e or s i S tio o t ns il C es o St nd ee iSi ply te S s lo pe d

accessory dwelling units

Conventional Perimeter Foundation Footing & Stem Wall extending below the frost line Frost-Protected Shallow Foundation Slab-on-Grade system with below grade insulation arranged to use building heat to raise the frost plain around the building.

Point Bearing

Pier & Beam Concrete piers bearing below the frost line with beam system elevating construction. Pin Footings Small profile bearings built to receive steel pins anchored below the frost line. Jack Pads Plastic-product pads are placed on grade with no excavation, incorporating adjustable elements to account for frost heave. 323

construction determinants / foundations

Cast or block stem wall

Interior drainage mat connected to drain 21’ x 13’ x 4.5’ = 1,228.5ft3 excavation (crawl space) 21’ x 13’ x 9’ = 2,457ft3 excavation (full basement) 14,400lb / [2(12’+20’)]= 225lb/ft

324

Interior trench drain Continuous footing Sizing per IBC 1809.7 1 story: 12” x 6” 2 stories: 15” x 6” 3 stories: 18” x 8” Perforated drainage pipe

accessory dwelling units

Conventional Perimeter Foundation Invasive

Low Impact

Long Install

Quick Install

Expensive

Inexpensive

Light-Weight

Robust

The conventional system consisting of a continuous footing and stem wall, extending below the frost line (48” in Boston) can be constructed with a crawlspace, or full basement. Naturally, this means extensive excavation and cost, but provides a well performing, familiar result.

Pros:

Cons:

• Tested & familiar construction • Permanent & Durable • Crawlspace/Basement provides easy access to utilities

• Extensive excavation requires heavy equipment and produces large amounts of fill that must be mitigated • Large amount of concrete required is does not address increasing sustainable concerns.

325

construction determinants / foundations

Protective facing required 21’ x 13’ x 1’

over insulation

= 237ft3 excavation Bearing is effectively directly

Thickened slab edge

translated to soil capacity Rigid insulation for Boston min R4.5 (total) required

min 12”

326

accessory dwelling units

Frost-Protected Shallow Foundation (FPSF) Invasive

Low Impact

Long Install

Quick Install

Expensive

Inexpensive

Light-Weight

Robust

Used in Sweden and throughout Europe, FPSF systems work by insulating around the outside perimeter of the slab foundation to allow the heat of the building to prevent ground freeze. This lets the entire foundation be far more shallow, requiring less excavation than traditional systems.

Pros:

Cons:

• Less excavation and cost compared to conventional perimeter foundations • Permanent & Durable

• Typical slab on grade condition makes accessing utilities difficult. • Exterior insulation may create termite vulnerability if not properly defended. • As slab must be on grade, sloped conditions may require more extensive excavation & construction similar to conventional perimeter wall systems.

327

construction determinants / foundations

Enclosure Wraps Bldg underside

Insulated Floor Cavity

6 x 0.4ft3 =

Beam Spans Piers

2.4ft3 excavation 14,400lb / 6 Piers = 2,400lb/pier

Tie Brackets Anchored to Piers Reinforced Concrete Pier

Poured of Precast Footing (may not be required, depending on load, soil conditions, and pier diameter) 4â&#x20AC;? Compacted Gravel

328

accessory dwelling units

Pier and Beam Invasive

Low Impact

Long Install

Quick Install

Expensive

Inexpensive

Light-Weight

Robust

Rather than excavating and pouring an entire foundation, a pier and beam system works by pouring piers and footings on a grid with the structure elevated on spanning beams. Piers must extend below the frost line, and are typically constructed on a precast or poured footing sized per load and soil conditions, with blocks or poured concrete cylinders extending to the structure.

Pros:

Cons:

• Less excavation and cost compared to conventional perimeter foundations: Cylindrical piers systems allow the use of an auger in lieu of larger, more invasive excavation equipment. • Permanent & Durable

• Doesn’t provide the lateral security as compared to conventional perimeter foundations and must be accordingly braced • Ill suited to non-uniform or very poor soil conditions

329

construction determinants / foundations

When used with posts, knee bracing is often incorporated for shear Pier or Beam Anchored w/ Bracket

6 x 0.4ft3 = 2.4ft3 excavation 14,400lb / 6 Piers = 2,400lb/pier

Pin Cap (seals pins while allowing access for inspection after installation) Pre-Cast Concrete Pier to receive pins Steel Pins Driven in 4-way configuration to bear as one unit

330

accessory dwelling units

Pin Footing Invasive

Low Impact

Long Install

Quick Install

Expensive

Inexpensive

Light-Weight

Robust

This system is a non-invasive procedure that produces minimal damage. It is a solid pin pile foundation that reaches deep into the ground without digging holes or pouring concrete. Typically, the pin length, in inches, matches the vertical dimension f the local frost depth. For a 48” frost depth, a 50” pin is recommended.

Pros:

Cons:

• • • • •

• Not as robust as concrete systems: may require additional bracing of floor plate structure.

non-invasive cost-effective removable pins no damage reduced time on site

331

construction determinants / foundations

Bracket Threaded adjuster Support Base - transfers load to base 0ft3 excavation 14,400lb / 15 Piers = 960lb/pier

â&#x20AC;&#x153;Packersâ&#x20AC;? - Incrementally stacking base members to counter ground fall While the material produced for Jack Pads do not mention or require it, often similar RV products with lightweight construction work in conjuncture with anchors.

332

accessory dwelling units

Jackpads® Invasive

Low Impact

Long Install

Quick Install

Expensive

Inexpensive

Light-Weight

Robust

The Jackpad is a fairly new product being implemented in the the UK. It is made from recycled plastic material, and bears directly on the ground, requiring essentially no excavation. While extensive testing has yet to be conducted, it has been used in a number of large, permanent case studies with seemingly positive results. This type of solution is similar to products currently available for RVs in America that haven’t been tested in more permanent situations. Pros:

Cons:

• • • • •

• Requires soil capacity of 2700 psf, or better • Low seismic performance • Extreme frost heave may require maintenance adjustments

cost-effective reusable built from recycled products no excavation required non-invasive

333

UTILITIES Because the work associated with utilities often requires specialized labor and permitting, and is equally invasive and extensive regardless of the size of the structure, utilities in ADUâ&#x20AC;&#x2122;s are especially prone to the economies of scale problem. Moreover, it is very difficult to eliminate or cost-engineer down the applications of utilities in dwelling scenarios, so when confined by inaccessible sites or other special concerns that may arise in constructing ADUâ&#x20AC;&#x2122;s, utilities become a major determinant. While there are often solutions for moving various utilities of grid into increased independence, they are often very expensive, and exceedingly more complicated than conventional on grid systems. Effectively, there are very few shortcuts to be had with utilities solutions, and the smaller a project is, the higher the percentage of the budget that must be allotted for these concerns will be.

334

construction determinants / utilities

336

Natural Gas

Plumbing

Electric

ce ss ib Po le or si S tio o t ns il C es o St nd ee iSi ply te S s lo pe d

poorly suited

On Grid Off Grid Host Dependent Host Independent Expensive Inexpensive

conditionally suited

well suited

di tio n

accessory dwelling units

Add a Meter & Subpanel Infrastructure added to exisitng system. Solar Array Several moderately sized panels, able to be coupled with battery systems. Connect Directly to the Mains Excavate water supply and sewer at street to add infrastructure, and run to building location. Connect to Host Infrastructure Cut into sewer and water supply where accessible in the existing building, and split off junction to new systems. Add Line to the Existing Manifold Connect new meter and infrastructure at existing access point. Use Alternatives Eliminate gas Completely, replacing with electric utilities already required on the project. 337

construction determinants / utilities

ELECTRIC OPTIONS Add meter & subpanel to existing / from street On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

As electric is generally accessible above ground, this “conventional” option is often quite feasible, as compared to other utilities. It is still a specialized trade dependent on skilled labor, so represents an unavoidable expense, but given its compact, flexible nature, is fairly low impact.

338

Pros:

Cons:

• The benefits of the grid: Uninterrupted and guaranteed • Conventional system is familiar to renters and doesn’t require owner maintenance.

• Specialty nature requires licensed electrician & codes • Doesn’t take advantage of the “economies of scale:” Will cost a similar amount regardless of the size of the house.

accessory dwelling units

Solar array On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

With their limited size, ADU’s are in many respects, well poised to take advantage of the benefits of sustainable power options. In the current technological climate, solar energy is the most feasible option to harness. There are a variety of options, ranging from comparatively simple panels and transformers to more intelligent arrays with batteries and backups.

Pros:

Cons:

• Stainability- Clean energy & Topical • More direct correlation of economic gain: with the smaller demand associated with ADU’s, it is more feasible to make a self sustainable unit than with larger homes

• Solar systems are still significantly more expensive than connecting with the grid • Most solar systems, in overcast climates especially, work in connection with the grid, so without more excessive redundancies, a solution probably wouldn’t eliminate the need for that infrastructure. • Depending on system, potentially more bulky. • Needs access to sun! Not independently suited to locations where existing infrastructure casts shadow. 339

construction determinants / utilities

PLUMBING OPTIONS Plumbing: Connect to the mains & sewer On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

Adding new water and sewer connections allows complete autonomy and optimal performance, however it is a very invasive, expensive process, and is ill suited to conditions limiting access and equipment intervention.

340

Pros:

Cons:

• Eliminates the middle man: Not dependent on the host building. • Direct, seamless, familiar operation

• Expensive! Can cost $10,000 or more. • Requires extensive exaction: it may not be feasible to connect to street infrastructure in inaccessible sites. • Invasive: Requires special permitting and fees to block road and interrupt regular flows.

accessory dwelling units

Plumbing: Connect to existing building’s infrastructure On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

Depending on the accessibility of the host plumbing, this can be a compelling alternative for accessing the water grid. While these solutions are dependent on the existing conditions, intelligent design of the ADU can make this work far cheaper and easier than connecting to the mains directly.

Pros:

Cons:

• Depending on the accessibility of plumbing, potentially much cheaper • Provides dependability of grid without having to access municipal infrastructure.

• Sub-metering puts onus on landlord • Renovations scenarios, such as basements or garages, may require labor intensive concrete work to achieve adequate slope.

341

construction determinants / utilities

ALTERNATE PLUMBING STRATEGIES Discharge: Black Water Black water refers to discharge water that has been contaminated in its use. This most commonly includes toilets and septic waster, but also other sources such as effluent from garbage disposals, and water that becomes mixed with harmful chemicals. The MassDEP (Department of Environmental Protection) has stringent regulations on handling black water, making it difficult to address off grid in urban settings.

Discharge: Grey Water

As plumbing is not a closed system, it is very difficult to make successful off grid strategies, and those that do exist often require significant investment, upkeep, space and balance that are ill-suited to tight urban environments. Furthermore, gravity is a significant factor in typical plumbing solutions. These considerations combine to make plumbing a major determinant. Effectively, the consideration of alternative plumbing strategies must address three categories:

342

Discharge that is not mixed with the above contaminants is considered grey water. Grey water is more easily dealt with than black water, and if separated properly, falls more into grey areas off the code. However, to remain truly grey water, specialized upkeep and proper use is required, avoiding strong chemicals and using bio-degradable detergents.

Supply The input in an off grid plumbing strategy must address the continual demand associated with the open nature of water use in domestic practice. This means large holding tanks are required, as well as expensive filtration equipment to achieve potable standards.

accessory dwelling units

Technologies like composting toilets may eliminate or significantly reduce black water production, but they are expensive, with systems costing upwards of $2,000, require upkeep, and are often stigmatized in their divergence from conventional solutions.

The most common off-grid strategies for grey water disposal typically rely on plantings and natural ecology, which require specialized upkeep, and are ill-suited to temperate climates and freezing.

Off-grid water supply systems essentially amount to rain water collection. These systems need adequately sized and designed collection fields, and are dependant on the weather, meaning extra redundancy must be built in. 343

construction determinants / utilities

NATURE GAS OPTIONS Natural Gas: Install additional gas line and meter On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

It is often possible to add a submeter and tie into the existing manifold, making running gas to a new addition on a home already connected to the grid relatively straightforward.

344

Pros:

Cons:

• Gas companies often make deals to cover some or all of the cost of the new meter and piping up to a certain distance (often 60-100ft) • Usage cost are cheaper than electric. • Provides a tested alternative to intensive applications like heating and cooking that could otherwise create a taxing load on electric systems.

• Additional specialty trade may slow and complicate build process: care must be taken protecting gas lines given the volatility of the product • Adding a line can be several thousand dollars if not covered by the gas company

accessory dwelling units

Natural Gas: Use alternatives On Grid Host Dependent Expensive

Off Grid Host Independent Inexpensive

Natural Gas applications almost always have an electrical counterpart, and in smaller homes especially, it may be desirable to eliminate the overhead associated with adding another utility to the project.

Pros:

Cons:

• Streamlines the construction and operation of the build by eliminating a trade • Generally easier/less liability to install and maintain electric: more flexibility

• Electricity is more expensive and often less efficient than gas • Applications like heating require a lot of power, and may preclude lighter electrical systems.

345

FRAMING How an ADU gets constructed is extremely important and there are many different factors to take into consideration. Two main categories for framing are conventional and prefabricated. The preferred method is based on site location, site restrictions, as well as site access, material availability and cost. Whether it is new construction, renovation, self-suffiecient, parasitic, or a kit of parts, there are many possibilities to consider when constructing an ADU.

346

construction determinants / framing

348

accessory dwelling units

Prefabricated

Conventional

To p of

ta c

t De

rv eOu

poorly suited

Permanent Temporary Host Dependent Host Independent On Site Prefab

conditionally suited

di tio n

well suited

Un it

FRAMING DETERMINANTS

Add a Meter & Subpanel New construction, typically site built.

Renovations Renovating and modifying an existing condition. Self-Sufficient Completely preassembled, factory made, brought onto site with no need for construction on site. Parasitic Completely preassembled and brought onto site, but cannot stand on its own. It needs to be attached to the existing structure. Kit of Parts Parts are assembled in factory, and brought and assembled on site.

349

construction determinants / framing

NEW CONSTRUCTION

permanent temporary host dependent host independent on site prefab

Tom Hudsonâ&#x20AC;&#x2122;s ADU This project is the most typical way to go about constructing and accessory dwelling unit. It is standard due to the slab on grade foundation and the stick frame construction process. This type of construction allows for an ADU to be independent from itâ&#x20AC;&#x2122;s host and only rely on it for utilities. It is entirely on site construciton.

350

accessory dwelling units

351

construction determinants / framing

RENOVATION before

permanent temporary host dependent host independent on site prefab

Blake Clark & Sabina Chen Basement Remodel This project is an ADU basement renovation. Renovations are common in ADU construction when there is too much space in the current house and when a space is outdated and unused. This project takes advantage of the natural light coming from the backyard to make it feel more open along with an open floor concept. Some special concerns come into play when renovating a space especially in the basement. These special conerns include water, insulation, egress access and light. 352

b after

accessory dwelling units

dimple membrane ~$0.4 - $0.5/sqft

steel stud wall

closed cell spray foam insulation ~$0.7-$1.0 /bdft

trench drain ~$50-$60 /ft 353

construction determinants / framing

SELF-SUFFICIENT truck size

8’-6”

11’

48’

8’-6”

11’

8’-6” standard - no permitting required 12’ wide - permit required 14’- 16’ wide - escort required

permanent temporary

8’-6”

host dependent host independent on site prefab

truck turning radius

60°

90°

b: 16’-0”

180°

critical swept path

Oversized Load (Width)

354

Drop House - d3 Architects

9 °0

This project is prefabricated in with all equipment pre-installed, fitting prefectly in a cargo container. Once dropped onto a site, it unfolds and pulls out.

a: 48’-0”

6 °0

a 5: -3 0 b 8:- 6

1 08 °

c iti rc las ew tpp th a

S at nd ard S em i-T ur ck

There is an ease of transportation as well as a sense of temporary placement.

accessory dwelling units

contained

unfolded

355

construction determinants / framing

PARASITIC s m a l l a n d l a r g e c r a ns e e x t e n t T lee cspociB o oC amr en N taion aC alr en1 93 5 2 T0 noc pa cat i y 143'

A lT rrea iC anr en Ta dn aAo FT1 01 -5 G 1 03T noc pa cat i y

jib

jib 122'

95' 42'

outrigger

72'

101' 130'

170'

24'-7"

340'-0"

20'-0"

190'-0"

56'

permanent temporary host dependent host independent 360° work area

360° work area

800 sqft

45 lbs/sqft

A lT rr ea iC anr en Ta dn aoA FT 1 01 G- 5 1 03T noc pa catyi

18 ton

ADU weight

T le cs pociB o mC ar en N taion aC alr n 1 e93 5 2 0T noc pa catyi

on site prefab

Rucksack House - Stefan Eberstadt

jib

143' 80° jib 122'

95'

° 42'

56'

356

72'

101' 130'

170'

This project’s significance is in its simplicity in construction and transportation. It has the ability to be shipped, dissasembled and reassembled with ease. It has the capability to combine architecture and art in a sculpture-like form. However, there are issues of thermal insulation, causing the project to be more temporary than initially thought.

accessory dwelling units

1 prefabricated welded steel enclosure + veneer plywood cladding

2 lifted by crane into position

3 anchored into facade on at four locatins and suspended from steel cables

357

construction determinants / framing

KIT OF PARTS

Labor Personnel

Com ponent

permanent temporary host dependent host independent on site prefab

Typical Panelized Construction Panelized systems offer a great variety in construction. Being prefabricated and assembled on site saves time during on site construction. Panelized systems often donâ&#x20AC;&#x2122;t need the use of large cranes therefore using small equipment and man power is sufficient. 358

accessory dwelling units

359

SOURCES

sources

INTRODUCTION HISTORY Content

• “Three Deckers.” Worcester Historical Society. http://www.worcesterhistory.org/worcesters-history/worcesters-own/three-deckers/ • Barley, M.W. “Rural Building in England”. In The Agrarian History of England and Wales, Vol. 5, p. 638. Press Syndicate of the University of Cambridge (1985). • “Timeline of Elder Cottage History.” Better Living Express. • Matthieu Lieteart. “The growth of cohousing in Europe.” Cohousing: The Cohousing Association of the United States. 16 December 2007. • The Cohousing Association of the United States. • www.accessorydwellingunits.org • Bolton, Elizabeth. “Triple Decker House Style Three Family Houses in Cambridge.” Centers & Squares. 24 April 2009. • https://sites.google.com/site/seourpicz/1/tvand-video/us/4/ Images

•“Three Deckers.” Worcester Historical Society. http://www.worcesterhistory.org/worcesters-history/worcesters-own/three-deckers/ • https://www.studyblue.com/notes/note/n/architecture-final/deck/6218386 362

• Barley, M.W. “Rural Building in England”. In The Agrarian History of England and Wales, Vol. 5, p. 638. Press Syndicate of the University of Cambridge (1985). • Matthieu Lieteart. “The growth of cohousing in Europe.” Cohousing: The Cohousing Association of the United States. 16 December 2007. • The Cohousing Association of the United States. • www.accessorydwellingunits.org • “Tiny Houses - small dwellings of every shape and size.” Design Boom. • Small House Bliss. www.smallhousebliss.com

CASE STUDIES Building Code Data

• http://www.broadhurstarchitects.com/residentialarchitecture/architecture_03 • http://www.jetsongreen.com/2011/07/asul-prefabadu-think-tank-georgia.html • http://www.contemporist.com/2015/05/09/thisold-laundry-boiler-room-has-been-transformed-into-aguest-apartment/ • http://www.velocipede.net/projects-1/2015/5/14/ huppert-mother-in-law-addition • http://www.pkmn.es/ALL-I-OWN-HOUSE • http://tinyhousesgalore.com/post/114228880691/ smallandtinyhomeideas-the-tiny-project-alek • http://www.usgbc.org/projects/puyallup-longhouse

• http://dortemandrup.dk/Lange-Eng-CollectiveLiving-copenhagen-2009 • http://www.stamerskontor.dk/node/105 • http://www.blairhinesdesignassociates.com/subcommercial-jamplain.html • https://www.flickr.com/photos/greenhavencohousing/10419162744 • http://www.modcell.com/news/eco-friendly-cooperative-paradise/

• http://verybradyblog.blogspot.com/2012/08/thebrady-bunch-backyard.html • http://www.itsfilmedthere.com/2010/03/bradybunch_02.html • http://fullhouse.wikia.com/wiki/Kimmy_Gibbler • https://sites.google.com/site/seourpicz/1/tv-andvideo/us/4/

PERCEPTIONS OF THE BACKYARD

PSYCHOLOGY OF NIMBYISM

Images

Content

• http://www.homedesignbee.com/backyard-landscape-design-for-kids/ • http://www.dwell.com/houses-we-love/article/ house-week-tiny-backyard-transformation-boston • http://www.dwell.com/houses-we-love/article/rundown-row-house-boston-becomes-quiet-urban-escapetwo-green-roofs • http://therearenoroads.com/internet-love/10-wisdom-filled-quotes-wilson-home-improvement/ • http://www.imcdb.org/images/047/107.jpg • http://www.hgtv.com/shows/going-yard • http://midwestconstruct.com/diy-yard-crasherspasadena-ca

• Fischel, William A.. “Why Are There Nimbys?”. Land Economics 77.1 (2001): 144–152. • Kiefer, Matthew. “The Social Function of NIMBYism.” Planetizen. 25 August 2008. Images

• Fischel, William A.. “Why Are There Nimbys?”. Land Economics 77.1 (2001): 144–152. • Kiefer, Matthew. “The Social Function of NIMBYism.” Planetizen. 25 August 2008.

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CITYWIDE SCALE MARKET POTENTIAL

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Map Data

Images

•United States of America. Department of Commerce. Census Bureau. N.p.: n.p., n.d. American FactFinder. Web. 10 Nov. 2015. <http://factfinder.census.gov>. •United States of America. City of Boston. N.p.: n.p., n.d. BostoMaps: Open Data. Web. 10 Nov. 2015. <http://bostonopendata.boston.opendata.arcgis. com/>. •United States of America. Department of Commerce. Census Bureau. N.p.: n.p., n.d. 2010 TIGER/Line Shapefiles. Web. 10 Nov. 2015. <http://www.census. gov>. •United States of America. City of Boston. Department of Neighborhood Development. N.p.: n.p., n.d. Affordable Housing List for Northeastern. Web. 10 Nov. 2015. •United States of America. City of Boston. Assessing Department. N.p.: n.p., n.d. Property Assessmentr 2014. Web. 10 Nov. 2015. <https://data.cityofboston. gov>.

•Neighbourhood of Back Bay from above Boston USA. Digital image. Photorator. N.p., n.d. Web. 10 Nov. 2015. <http://photorator.com>. •Thumbs Up Seniors. Digital image. Michaelczinkota. N.p., 28 Apr. 2014. Web. 10 Nov. 2015. •Lin, George X. Boston After Superstorm Nemo. Digital image. X.Lin Design and Photography. N.p., 9 Feb. 2013. Web. 10 Nov. 2015. <http://georgexlin.com>. •Vacant House. Digital image. Flip2Freedom. N.p., 1 Dec. 2010. Web. 10 Nov. 2015. <http://www.flip2freedom.com>. •9-11 Sagamore Street Family. Digital image. Common Ground Development Corporation. N.p., n.d. Web. 10 Nov. 2015. <http://www.commongroundhousing. org>. •For Rent Sign. Digital image. FOX News Radio: 1310 KLIX. N.p., 15 June 2012. Web. 10 Nov. 2015. <http://newsradio1310.com>. •Robinson, Matt. Back Bay Brownstones From Above. Digital image. MetroScenes Urban Photography. N.p., May 2012. Web. <http://images.metroscenes.com>. org>. •Hand with Keys. Digital image. Huffington Post. N.p., 16 July 2014. Web. 10 Nov. 2015. <http:// www.huffingtonpost.com>.

NEIGHBORHOOD SCALE BOSTON ZONING

JAMAICA PLAIN

Map Data

BRA Zoning Code

•Same as MARKET POTENTIAL

•Article 55 - Table 4

NEIGHBORHOODS

HYDE PARK

Map Data

BRA Zoning Code

•Same as MARKET POTENTIAL

•Article 69- Table C

WEST ROXBURY BRA Zoning Code

•Article 56 - Table D

EAST BOSTON BRA Zoning Code

•Article 53 - Table F

DORCHESTER BRA Zoning Code

•Article 65 - Table C

COMMERCIAL DISTRICT Images •http://www.bing.com/maps/?FORM=Z9LH2

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BUILDING SCALE ANAL YSIS TYPOLOGIES

STRUCTURE

Images

Content

•www.maps.google.com

•http://www.dreamstime.com/royalty-free-stock-images-interior-framing-new-house-image22754379 •http:// www.doityourself.com/stry/platform-framingvs-balloon-framing#b • http://college.holycross.edu/projects/worcester/ immigration/3deckers.htm • https://en.wikipedia.org/wiki/Multi-family_residential

TYPOLOGICAL EXAMPLES Boston Redevelopment Authority Data

•https://archive.org/details/bostonstripledec00bost Images

•www.maps.google.com

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BUILDING ORGANIZATION

DESIGN OPPORTUNITIES

Building Code Data

Content

•http://www.mass.gov/eopss/consumer-prot-and-buslic/license-type/csl/8th-edition-base-code.html •http://www.mass.gov/eopss/docs/dps/ inf/780cmr/780-8th-51.pdf • http://publicecodes.cyberregs.com/icod/

•https://waynehomeremodel.wordpress.com/tag/ framing/

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CONSTRUCTION DETERMINANTS

368

FOUNDATIONS

UTILITIES

•Hybrid Foundation Insulation Retrofits: Measure Guideline. U.S. Department of Energy. http://buildingscience.com/documents/bareports/ba-1108-hybridfoundations-retrofits-measure-guideline/view • Design Guide for Frost Protected Shallow Foundation systems, U.S. Department of Housing and Urban Development Office of Policy Development and Research. http://www.huduser.gov/Publications/PDF/ FPSFguide.pdf • Designing Pier Footings, Deck Magazine. http:// www.deckmagazine.com/Images/Designing%20 Pier%20Footings_tcm122-1377810.pdf • Types of Crawlspace footings. http://www.foundationmaster.com/foundation-footing-pier-wall-ga-sc. html •Pin Foundations, Inc. http://www.diamondpier.com/ • IBC Chapter 18. http://codes.iccsafe.org/app/book/ content/PDF/2006/2006_NewJersey/NJ_Building/ PDFs/NJ_Bldg_Chapter18.pdf

• Public Works & Utilities. City of Boston. http:// www.cityofboston.gov/residents/PublicWorksAndUtilities.asp • Renew Boston Solar, City of Boston. http://www. cityofboston.gov/eeos/conservation/solar.asp • Regulations Governing the Use of the Water Distribution Facilities of the Boston Water and Sewer Commission, Boston Water and Sewer Commission. http:// www.bwsc.org/REGULATIONS/WaterRegulations. pdf • http://www.homeadvisor.com/cost/plumbing/ install-a-sewer-main/ • Practical Alternatives to Sewer and Septic Systems. http://www.letsgogreen.com/index.html • Greywater Systems in Freezing Climates. http://greywateraction.org/systems-for-cold-climates-includingwetlands/ • Using Composting Toilets and Greywater Systems in Massachusetts, Massachusetts Department of Environmental Protection. http://www.mass.gov/eea/docs/ dep/water/wastewater/a-thru-n/comptoi.pdf • http://www.costowl.com/home-improvement/hvacgas-line-piping-cost.html

SOURCES FRAMING • “Tom Hudson’s ADU: A Sneak Peak at an ADU Under Construction” <http://accessorydwellings. org/2014/05/09/tom-hudsons-adu-a-sneak-peek-atan-adu-under-construction/> • “2014 Portland ADU Tour: Thomas Hudson Decides Smaller is Better” http://www.oregonlive.com/multimedia/index.ssf/2014/05/2014_portland_adu_tour_ thomas.html • “Blake Clark and Sabina Chen’s ADU: A Basement Remodel” http://accessorydwellings. org/2014/11/30/blake-clark-sabina-chens-adu-a-basement-remodel/> • http://www.northeastern.edu/camd/architecture/ portfolio/prefab-city/ • “Prefab Friday: Drop House” http://inhabitat.com/ drop-house/ • “Parasite Perspective – New Vies on the City” http://www.convertiblecity.de/projekte_projekt02_ en.html •“How We Build” http://inspiredindependence.com/ how-we-build/

• http://mywrittenromance.com/wp-content/ uploads/2013/12/o-STACK-OF-BOOKS-facebook. jpg

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