Net Zero Building Compendium

NET ZERO COMPENDIUM Case Studies on Inclusionary Net Zero Housing Projects Tyler Edward Wade May 5, 2017

ARC671-Advanced Case Studies in Sustainable Design Professor Keelan Kaiser

CASE STUDIES

performance, low-income housing project development model.

1.1 Background In 2007, Boulder County Housing Authority (BCHA) created a strategic vision for a 14-acre parcel of land in Lafayette, Colorado that the agency had held available, but undeveloped, for the past decade.

The property1 would become known as Josephine Commons and is designed to Josephine Commons house 153 residential housing units. A computer rendering of the development is provided in Figure 1.

HB&A Architects, Farnsworth Group, and NREL

Case Studies

HB&A ARCHITECTS

BACKGROUND

Figure 1. Josephine Commons residential community

(Image from HB&A Architects) Affordable housing development authorities throughout the United States continually struggle to find the most cost-effective pathway to provide quality, durable, and sustainable housing. The challenge for these authorities is to achieve the mission of delivering affordable 1 housing at the lowest cost per square foot in environments that may be rural, urban, suburban, or within a designated redevelopment district. With the challenges the U.S. faces regarding energy, the environmental impacts of consumer use of fossil fuels and the increased focus on reducing greenhouse gas emissions, housing authorities are pursuing the goal of constructing affordable, energy efficient and sustainable housing at the lowest lifecycle cost of ownership.

This report outlines the lessons learned and sub-metered energy performance of an ultralow energy single family ranch home and duplex unit, called the Paradigm Pilot Project and presents the final design recommendations for a 153-unit net zero energy residential development called the Josephine Commons Project. In addition to describing the results of the performance monitoring from the pilot project, this paper describes the recommended design process of (1) setting performance goals for energy efficiency and renewable energy on a life-cycle cost basis, (2) using an integrated, whole building design approach, and (3) incorporating systems-built housing, a green jobs training program, and renewable energy technologies into a replicable high performance, low-income housing project development model.

Case Studies Josephine Commons1 Figure 6. Paradigm Pilot Project duplex rendering, south side

(Image from HB&A Architects)

HB&A ARCHITECTS

HB&A ARCHITECTS

Figure 7. Paradigm Pilot Project duplex, north side ENERGY CONSERVATION STRATEGIES

(Photo from BCHA)

Passive Solar Design

Figure 13. Single-story ranch

(Photo from BCHA) The first floor plan and elevation rendering are provided in Figure 14.

The ranch house was designed with an aspect ratio that increases the south facing wall area 14 relative to the east/west facing wall area. The design also included a high window to wall ratio on the south facade, and minimized windows on the north, east, and west facade.

Exterior South facing louvers block direct summer sun and allows low winter sun to penetrate.

Natural Ventilation Operable clerestory windows allow for hot air to rise from the space and escape outside. The large open volume space allows for increased circulation of air in that particular space.

Natural Daylighting Clerestories bring in natural day-light into the kitchen, living room, and hallways. Using high natural daylighting strategies, along with a volume space, allows light to penetrate deeper and provide extra daylight that would not otherwise be there.

Ground Source Heat Pump A GSHP provides heating and cooling to the house through a central heating/cooling coil and air handling unit. The GSHP is a 3-ton, Climate Master Tranquility 27 unit. The heat pump has a dual-stage compressor and is one of the most energy-efficient heat pumps on the 20 market.

Case Studies Josephine Commons1

The first and second floor plan and elevation rendering are provided in Figure 8.

HB&A ARCHITECTS

HB&A ARCHITECTS

ENERGY PRODUCTION STRATEGIES Figure 8. Duplex unit floor plan and elevation rendering

Condensing Furnace

(Image from HB&A Architects)

Figure 14. Ranch house floor plan and elevation rendering

(Image from HB&A Architects)

The single-family house included a number of innovative energy systems and integra design of the following:

The duplex included a number of innovative energy systems and integrated the following design elements:

•

Passive Solar Design. The ranch house was designed with an aspect ratio

increases the south facing wall area relative to the east/west facing wall area. The design also included a high window to wall ratio on the south façade, and minimized windows on the north, east, and west façade.

•

Natural Daylighting. Clerestories bring in natural day-light into the kitche room, and hallways.

increases the annual south facing wall areause relative to the east/west facing wall a Each duplex was heated with a condensing gas furnace, with an fuel efficiency design also included a high window to wall ratio on the south façade, and • Passive Solar Design.

The ranch house was designed with an aspect ratio that of 96%. windows on the north, east, and west façade.

• Energy Star Lighting. Compact florescent lighting was used in 100% of th Automated Natural Ventilation. A natural ventilation system was designed to work wired lighting fixtures. with the clerestory windows. A temperature sensor was installed on the 2nd floor and another temperature sensor was installed outside of the duplex, and measured outside • Energy Star Appliances. All of the appliances are Energy Star rated, inclu air temperature. Electronically operated window operators were installed on the refrigerator, dishwasher, and clothes dryer. clerestory windows, and the control sequence for the natural ventilation system was On-demand water heater. A natural-gas-fired on-demand water heater provides • Ground Source Heat Pump. A GSHP provides heating and cooling to the set up such that the system would open the windows if the second floor temperature through a central heating/cooling coil and air handling unit. The GSHP is was above 78 °F and hot the outside air temperature was lower than 78 °F. A graphic of supplementary water to each residence.

Climate Master Tranquility 27 unit. The heat pump has a dual-stage comp the control sequence is provided below. is one of the most energy-efficient heat pumps on the market. The namep specifications for the geothermal heat pump system are as follows: •

Solar Hot Water

Photovoltaics

15 A 2.2 kW roof-mounted PV array was installed on each residence.

21

Energy Recovery Ventilator Mechanical ventilation systems were upgraded to a balanced ERV with a sensible recovery effectiveness of 75%, and a total recovery effectiveness of 62%. The balanced ERV is set up to cycle on off and off for a total run time of 8 hours a day. In addition, a wall-mounted switch in each restroom will turn on the ERV for 10 minutes once the switch is activated.

Lighting Lighting Heating Heating

Pin-base CFLs Pin-base CFLs AFUE 80% AFUE 80%

Ventilation Mechanical Ventilation CaseMechanical Studies DHW DHW

Bathroom exhaust Bathroom exhaust Standard electric Standard electric

1= Effective Leakage Area Note: ELAELA Note: = Effective Leakage Area Josephine Commons

eThe baseline design waswas analyzed in BEopt andand compared to the 2008 baseline Building America Data Collection baseline design analyzed in BEopt compared to the 2008 baseline Building America nchmark.

TheThe benchmark is consistent with mid-1990s standard practice, as reflected in the Benchmark. benchmark is consistent with mid-1990s standard practice, as reflected in the 1 21 2 me Energy Rating System (Figure 3).

Home Energy Rating System (Figure 3).

Note: MBtu = million British thermal unitsunits Note: MBtu = million British thermal

42% reduction

Figure 3. Building America benchmark versus baseline design source energy useuse Figure 3. Building America benchmark versus baseline design source energy

eThe baseline BCHA duplex model projected a source energy savings of 42% when compared to to baseline BCHA duplex model projected a source energy savings of 42% when compared Building America Benchmark.

Source energy savings is represented as the amount of energy the Building America Benchmark. Source energy savings is represented as the amount of energy ed at this site,site, as well as energy losses through thethe generation andand distribution system.

Thus, it it used at this as well as energy losses through generation distribution system.

Thus, ptures the total amount of energy required to get the total energy to the site and accounts for captures the total amount of energy required to get the total energy to the site and accounts for

1 endron, R.; R.; Engebrecht, C. (2010).

Building America Benchmark Definition.

NREL/TP-550-47246.

Golden, CO:CO: Hendron, Engebrecht, C. (2010).

Building America Benchmark Definition.

NREL/TP-550-47246.

Golden, EL. http://www.nrel.gov/docs/fy10osti/47246.pdf.

NREL. http://www.nrel.gov/docs/fy10osti/47246.pdf.

2PA. ENERGY STAR Program, Home Energy Rating, EPA. ENERGY STAR Program, Home Energy Rating, ://www.energystar.gov/index.cfm?c=bldrs_lenders_raters.nh_HERS http://www.energystar.gov/index.cfm?c=bldrs_lenders_raters.nh_HERS

37% reduction

5 5

Figure 4. Source-energy savings and incremental costs of of optimized design Figure 4. Source-energy savings and incremental costs optimized design

e proposed design results in in a source-energy savings of of 37% over thethe proposed BCHA The proposed design results a source-energy savings 37% over proposed BCHA eline design and reduces the incremental mortgage and utility costs by approximately aseline design and reduces the incremental mortgage and utility costs by approximately 6/yr.

166/yr.

ble 6 provides thethe final setset of of recommended design parameters.

Table 6 provides final recommended design parameters.

Case Studies Kaupuni Village2 Hawai‘ian Home Lands Trust, U.S. Department of Energy and NREL

HAWAI’IAN HOME LANDS TRUST

BACKGROUND Affordable housing development authorities throughout the United States continually One of Hawai‘i’s outstanding accomplishments in its multi-pronged efforts toward energy independence is Kaupuni Village—the first net-zero energy affordable housing community in the state. It has achieved the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED®) Platinum designation.

The Kaupuni Village project is a prime example of local partners working with federal technical and financial assistance to integrate energy efficiency and renewable energy technologies in an application with local imp act and replicable lessons learned.

KAUPUNI VILLAGE:

Comprised of 19 single-family homes and a community center, the uniqueness of Kaupuni Village is not only that the structures are built to be net-zero energy, but that the entire community was envisioned as a fully self-sufficient and sustainable environment in keeping with traditional Hawai‘ian cultural practices known as ahupua‘a, where everything needed to live sustainably is provided from the local ecosystem.

A closer look at the first net-zero energy affordable housing community in Hawai‘i

Each of the high-performance homes incorporates energy efficiency and renewable energy technologies to reach net-zero energy usage. From the south-facing orientation of the houses and their roof angles to the pervious concrete driveway to capture runoff and reduce the urban heat island effect, no detail was spared to make the homes as efficient as possible.

Case Studies Kaupuni Village2

HAWAI’IAN HOME LANDS TRUST

ENERGY CONSERVATION STRATEGIES Nahale-a, chairman of the Hawai‘ian Partners rally on ground-

reach net-zero energy usage. From the south-facing orientation of the houses Homes Commission and a native breaking community and their roof angles to the pervious Hawai‘ian who was born and raised One of Hawai‘i’s outstanding accomconcrete driveway to capture runoff on Hawai‘ian homesteads. “We plishments in its multi-pronged and reduce the urban heat island turned to our kupuna (ancestors) and efforts toward energy independence Deep overhangs and awnings block the high summer sun tothe prevent solar heat gain the effect, no detail was sparedinto to make our Hawai‘ian values in shaping is Kaupuni Village—the firstfacing net-zero building the homes as efficient as possible. foundation of Kaupuni’s and designroof and angles space. Predominate south orientation maximize the natural energy affordable housing community philosophy—malama ‘aina (take care daylight. in the state. It has achieved the U.S. Each home was designed to have at of the land) in developing its green least 40% lower energy consumption Green Building Council’s Leadership features and kaiaulu (community) than the baseline, which is minimally in Energy and Environmental Design in creating the community spirit of 2006 International Energy Conserva(LEED®) Platinum designation. the project.” tion Code (IECC) compliant. Energy The Kaupuni Village project is a prime efficiency is achieved through a variety Comprised of 19 single-family homes The steepexample sloped roofs andworking pervious driveway capture and reduce of local partners with concrete of measures, including: the and a community center, the unique- runoff urban heat island effect federal technical and financial assisness of Kaupuni Village is not only that • Optimal building envelope design tance to integrate energy efficiency the structures are built to be net-zero • ENERGY STAR® appliances and renewable energy technologies in energy, but that the entire community an application with local impact and was envisioned as a fully self-sufficient • High efficiency lighting and replicable lessons learned. and sustainable environment in keepdaylighting with good solar control For interior spaces hard to get natural ing daylight into, Hawai‘ian solar tubes with traditional culturalare used on the roof to get • Natural ventilation Led by Hawai‘ian Home Lands Trustinterior spaces. natural daylight into those deep practices known as ahupua‘a, where and its partners—with assistance from • High efficiency air conditioners everything needed to live sustainably is the U.S. Department of Energy (DOE) provided from the local ecosystem.

• Solar water heating. and the National Renewable Energy

Passive Solar Design

Water Capturing

Solar Tubes

Laboratory (NREL), Kaupuni Village “The driving force behind Kaupuni Efficient Building Insulation took shape in the Waianae Valley in Oahu. The dedication held April Highly insulated buildingwas envelope 2011, and residents moved in the operation. following month.

Village was for it to be a sustainable community,” Kosolfor Kiatreungwatreduces the said need heating tana, NREL’s Kaupuni Village technical lead. “We applied modern technologies to create housing that supports The land was provided by the Departthe traditional Hawai‘ian values of ment of Hawai‘ian Home Lands sustainability and environmental (DHHL), and homeowners were stewardship.” selected from a waiting list of native Hawai‘ians for whom DHHL is comA perfect pairing: energy mitted to helping attain home or

A PV system on each house provides the renewable electricity to make the home net-zero energy. and cooling systems Sustainable features throughout the community include maximizing open space, incorporating native species, water-wise landscaping, edible gardening, hydroponics, and aquaculture.

Nearby Ka‘ala Farms, which was a partner in the project, has held workshops for residents on how to construct

Case Studies

“

Kaupuni Village2

The synergy between the project partners was key to Kaupuni Village’s success.

We had a common goal so that made for a strong collaboration.

— KOSOL KIATREUNGWATTANA, NREL

HAWAI’IAN HOME LANDS TRUST

Lessons Learned Kaupuni Village is a prime example of local partners working with federal technical and financial assistance experts to integrate energy efficiency and renewable energy into an affordable housing community. Here are the top takeaways from the project:

ENERGY PRODUCTION STRATEGIES 1. The concept of net-zero energy is achievable and

replicable in a residential community.

Aquaponics

2. Good energy analysis and energy efficiency planning

5. The exchange of knowledge between homeowners accelerates adoption of energy-wise habits and fosters shared values.

Enables homeowners to raise fish and grow vegetables for food. This is not directly an active should take place early in the design process because 6. Homeowner education and continuing reinforcement of of the difficulty in making changes later. Such changes energy efficiency practices provided by the utility, the system for the building, but does promotes some sustainable features that will allow greater can add significant costs to a project, including time, contractor, and technical experts is important to creating net-zero efficiency. labor, and materials. and sustaining energy consumption awareness.

3. Collaboration between the design team, government entities, local partners, and residents is critical to project success.

Solar Hot Water

4. Incorporate energy efficiency first and fill the gap with Photovoltaics specifically designed for solar hot renewable energy to achieve net-zero energy goals. In trying to heat water. the Kaupuni Village model, energy efficiency measures reduced energy consumption more than 40% over baseline. This resulted in a significant reduction in the need for renewable energy to achieve net zero.

Photovoltaics

7. Much like vehicle mileage is dependent on how people drive, energy consumption performance in a net-zero energy house is driven by homeowner behavior. Based on ongoing monitoring of energy usage in the Kaupuni water use allows for lower electric bills Village community, there was a variation of energy usage from home-to-home due to individual homeowner behavior. However, the community overall continues to achieve net-zero energy performance.

when

A 2.2 kW roof-mounted PV array was installed on each residence. A highly reflective roof 1 photo from Group 70, NREL/PIX 20155. Page 2 photos (top to bottom): iStock/17841424, iStock/10196394, iStock/1359888, iStock/9468980, iStock/92289, color andPage material increase the ambient light that is being consumed by the PV panels. iStock/7093707. Page 3 photo from Ken Kelly, NREL/PIX 20154. Page 6 photos (top to bottom): Ken Kelly, NREL/PIX 20156; Kimo Kai, Department of Hawai‘ian Home Lands, NREL/PIX 20157; Ken Kelly, NREL/PIX 20158; Ken Kelly, NREL/PIX 20159. Page 8 illustration from Group 70

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

DOE/GO-102012-3465 • May 2012 Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 10% post consumer waste.

STATE OF

HAWAII

ts e of dnd gy.

ng

he

at onal es. uces

e

Kaupuni Village2 Data Collection

14,700

14,640 Hot Water

2,100 Site Electricity Use (kWh/yr)

nts

Case Studies

Cooling

11,760

Cool Fan/Pump 4,680

8,411 (136)

8,820

Large Appliances

889 5,880

Lights

1,778

2,636

Miscellaneous

498

( ) Excess Electricity, Total−PV

2,271

2,016

2,921

2,920

Standard House

Kaupuni Village Net-Zero Energy House

2,940

0

This NREL chart shows energy usage of a standard house vs. a net-zero energy house in Kaupuni Village.

Homeowners can monitor their energy use through an electric net energy meter, which registers electrical flows in either direction. The benefit is residents are offered the opportunity to live an energy-efficient lifestyle and only pay the utility company a minimum connection charge of $16 per month.

sure I make the most of my home and share that information with other people.�

Net-zero energy projects on deck Kaupuni Village is one of many new energy-efficient residential and commercial developments in which DOE and NREL are providing techni-

Case Studies zHome Multifamily Complex3 Vandervort Architects, Howland-Ichijo USA and 2020 Engineering 5

Photo: Ichijo USA

zHOME MULTIFAMILY COMPLEX CASE STUDY

ICHIJO USA

BACKGROUND

building, it is very important for design teams to encourage residents to conserve energy. There are a variety of ways to achieve this, both directly and indirectly.

Direct approaches include education, usage feedback, and other solutions that target occupant behavior by communicating with the occupant in one way complexorwas the first zero net energy project of its kind in the United another.

The zHome multifamily States. Completed in 2011, zHome is a pioneering demonstration of sustainability. The Table 1: Demand Side Energy Direct Indirect complex is made up of 10 units and a shared community area. The design approach of Conservation Strategies at zHome Energy feedback monitors Heat recovery ventilation the project centered on energy efficiency, but also included a focus on reduction of water Phantom load switchand outletsminimizationNatural ventilation use, locally-sourced and recycled products, of storm water discharge.

Educational daylighting Launched as a market catalyst to bring sessions sustainable housing toExtensive everyday people, zHome has LED lighting proven to be a strong example of successful sustainability at the multifamily scale. Since the project was completed, more than 100 multifamily projects have eitherappliances achieved or are High efficiency pursuing zero net energy performance.

Indirect approaches to reduce occupant-driven energy consumption include: automatically resetting controls, specifying high-efficiency equipment and The project was a joint venture between the City of Issaquah and the builder, Ichijo USA. The lighting, incorporating energy recovery systems, and other design aspects which City provided the property with encourage the intention of building a project that would serve as both occupants to save energy (e.g. daylighting and operable windows for an affordable housing project and a sustainable demonstration development.

In exchange cross-ventilation).

In contrast, occupants in commercial buildings seldom have for providing the land free of charge to the developer, the City of Issaquah required that access to a thermostat or operable windows and commercial HVAC schedules arethe zHome project meet strict sustainability guidelines, including zero net energy performance. usually preset. Table 1, above, highlights the various strategies used in the zHome The developer was also responsible absorbing market risksloads. during tough economy.

To projectfor to address these occupant-driven The a educational sessions coupled promote the sustainability of thewith project, one of the 10 housing units was also reserved as the energy feedback monitors allow the residents to learn what impact their a behavior has on theircenter consumption.

Thisto encourages residents to take advantage model unit that would serve as an education for up five years. of daylighting, natural ventilation, and phantom load switches as tools to minimize their consumption.

As seen in Figure 2, the overall per capita net energy consumption has steadily declined in the zHome units during the measured period of April 2013 to May 2014.3 Living in a building which is striving for resource conservation may influence occupants to monitor their energy usage and conserve more.

3 More analysis would be needed to determine what share of this energy reduction is attributable to weather patterns.

However, the data suggest that part of the reduction in energy use is due to a behavioral shift in the occupants over time.

Case Studies zHome Multifamily Complex3 zHOME MULTIFAMILY COMPLEX CASE STUDY

3

ICHIJO USA

Awards & Certifications:

The effectiveness of the energy efficient design is validated in the energy consumption data. The energy consumption from all of the metered homes (eight of 2012 U.S. Department of Energy ENERGY CONSERVATION STRATEGIES ten homes were metered) was far below the city average of 2,764 kWh. The all-electric Builder’s Challenge zHome units averaged 612 kWh of energy consumption per month, an approximately 78% reduction. The primary energy efficiency measures employed are: Passive Solar Design 2012 Northwest Energy Star Project of the Year • High performance appliances

Effective orientation and overhangs block high summer sun and allow low winter sun to • R-38adequate Wall insulation 2011 Residential Project of space the Year and in penetrate deep into the provide natural daylighting.

• R-60 Ceilings • R-55 Structurally Insulated Panels (SIP Roof) Natural Ventilation 2009 Smart Partnership Award • U-0.30 Double paned low-e, argon filled windows • 0.20 Air changes per hourto the air circulation in their Operable windows allow the users to have direct connection Ground sourcemakes heat pumps unit. Educating the users about energy•conservation natural ventilation consistency • Low flow water fixtures (reduce hot water consumption) easier to maintain.

• LED lighting Ground Source Heat Pumps • Daylighting • Smart switches to cut standby power loads North America

Utilizing the constant ground temperature, the ground source heat pumps make the warming and cooling of water in the Renewable building more energy efficient. Starting at a Energy Generation temperature that is constant throughout the year means the mechanical systems are Each unit has its own individual solar photovoltaic array. The arrays are sized to working a lot less to warm or coll the building.

meet the anticipated loads of the unit. The average array capacity for the units is 6.6 kW. To reach zero net energy, the zHome dwellings rely directly on the grid to Efficient Building Insulation handle over- and under- production, essentially using the grid as a battery. As seen in Figure 1 below, Insulated the buildingsPanels export energy the total grid in building the summer and impor With R-38 Walls, R-60 Ceilings, and R-55 Structurally (SIPS)tothe energy from grid in winter.

These buildings areof net-metered, which means that insulation is super insulated so immediately the the building doesn’t need a lot mechanical the exported electricity is purchased by the utility at retail rates.

Residential scale capacity to stabilize it. energy storage with batteries was deemed cost prohibitive at the time and was no included2.

Figure 1: Total Average Solar Production vs. Total Average Energy Consumption (Source: Built Green)

Case Studies zHOME MULTIFAMILY COMPLEX CASE STUDY

6

Photo: Ichijo USA

zHome Multifamily Complex3

ICHIJO USA

Successes

TheSTRATEGIES zHome project has successfully demonstrated that zero net energy ENERGY PRODUCTION

performance on a residential scale is achievable, despite the challenge of increased impacts of occupant behavior. zHome units use 60-80% less energy than a typical home in the area. Indirect solutions rooted in passive efficiency, coupled with direct solutions which center around occupant engagement have This device keeps the heat in through air exchanges while getting the stale air out. Usually kept notoriously variable and unpredictable occupant-driven loads relatively low. there is heat and air loss in air exchanges, but this equipment keeps the warm air in while the zHome has performed at zero net energy for the past two years, showing that the stale air is being exhausted. project has maintained its ambitious high-performance goals over time.

Heat Recovery Ventilation

Smart Power Switches Lessons Learned •

As with most zero net energy projects, establishing early project goals and

•

Informed design choices were made using energy models and renewable energy costing to ensure that all cost-effective efficiency measures were included before layering in renewables.

•

The zHome project, through its delays due to the economy, benefitted from

Plug loads are some of the biggest contributers to energy loss, so these smart switches cut Figure 2: Net Energy Usage by Unit from April 2013embracing a fully integrated design process is crucial for success. power to standby power loads. Any plug that is not being used for energy can be cut May the 2014 (Source: Built Green) • High-performance projects need an educated design team and builder who at any time so that there isn’t a loss in energy when things are plugged in and someone isn’t are familiar with the latest technologies and sustainable best practices. home.

For More Information Photovoltaics

“zHome Reaches the Stars: A Built

Each has its Case ownStudy,” individual solaraphotovoltaic arrays sized to meet the fresh evaluation of array. available The materials on theare market.

Project specifications Greenunit Emerald-Star King anticipated array capacity for units is 6.6 kW. To reach were revised to take include some of the the new materials.

County, 2012. loads of the unit. The average zero net energy, the zHome dwellings rely directly on the grid to handle overand under• Occupant-driven energy use was reduced by both direct (e.g. education “zHome Case Study,” International production, essentially using the gridand asfeedback) a battery and indirect (e.g. operable windows, daylighting and natural Living Future Institute, 2013.

“zHome: Setting a National Net Zero Energy and Green Building Precedent,” Built Green, 2015. zHome Website: http://z-home.org/index.php

ventilation) approaches.

Climate Zone: 4C

in the Un Total Costs: $3,034,000 (land excluded) of sustain Case Studies zHome Multifamily Complex$180/SF (land excluded) area. The Hard costs: Data Collection included Soft costs: $46/SF The effectiveness of the energy efficient design is v Awards & Certifications: and minim consumption data. The energy consumption from a 2012 U.S. Department of Energy ten homes were metered) was far below the citysus ave bring Builder’s Challenge units averaged 612 kWh of energy consump Measured EnergyzHome Stats example 78% reduction. The primary energy efficiency measu 2012 Northwest Energy Star Project of the Year • High performance appliances was com • R-38 Wall insulation 2011 Residential Project of the Year in pursuing 3

21 - 22 = -1

• R-60 Ceilings • R-55 Structurally Insulated Panels (SIP Roo BUILDING’S RENEWABLE BUILDING’S The filled proje 2009 Smart Partnership Award • U-0.30 Double paned low-e, argon win TOTAL EUI PRODUCTION RPI NET EUI • 0.20 Air changes per hour USA. The • Ground source heat pumps would se Site Energy Use Index (EUI)• kBtu/SF/year Low flow water fixtures (reduce hot water co • energy LED lighting developm The Energy Equation: the building use minus the Su • Daylighting renewables production equals the net energy of the the CityThe o • Smart switches to cut standby power loads North America

building. Buildings may be ‘Getting to Zero’ and have a net EUI per guidelines Renewable Energy above zero. If renewable production exceeds energy useGeneration its net inc responsib unit hassurplus its ownenergy. individual solar photovoltaic EUI is below zero (negative) andEach it is creating tha

meet the anticipated loads of the unit.

The averag sustainab cou 6.6 kW. To reach zero net energy, the zHome dwe kep handle over- and under- production,model essentiallyun us zH in Figure 1 below, the buildings export energy to th pro energy from the grid in winter. These buildings are the exported electricity is purchased by the utility a For more information: energy storage with batteries was deemed costLe p 2 newbuildings.org/zero-energy included .

1 Source: Int•

Figure 1: Total Average Solar Production vs. Total Figure 2: Net Energy Usage by Unit from April 2013Average Energy Project Consumption (Source: Built Green) May 2014 (Source: Built Green) Profile developed

by New Buildings Institute ©2016

•

•

SUSTAINABLE DESIGN STRATEGIES MATRIX JOSEPHINE COMMONS Passive Solar Natural Ventilation Ground Source Heat Pumps Efficient Building Insulation Photovoltaics Heat Recovery Ventilation Smart Power Switches Solar Hot Water Aquaponics Solar Tubes Water Collection Condensing Furnace Energy Recovery Ventilator Natural Daylighting

KAUPUNI VILLAGE

zHOME MULTIFAMILY COMPLEX

REFERENCES

NOTES 1. JOSEPHINE COMMONS Source: http://www.nrel.gov/docs/fy12osti/51450.pdf 2. KAUPUNI VILLIAGE

Source: https://energy.gov/sites/prod/files/2014/05/f15/53401.pdf 3. zHOUSE MULTIFAMILY COMPLEX

Source: http://newbuildings.org/wp-content/uploads/2016/10/zHomes.pdf