further revised book

Compiled by Lisa Hammershaimb

The Urban Living Roof Movement

open space

Open space, in this book, refers exclusively to the open places on the tops of buildings found within urban spaces.

Editor’s note

Compiled by Lisa Hammershaimb

The Urban Living Roof Movement

open space

Open Space book design Š 2009 Lisa Hammershaimb Published by Lisa Hammershaimb as part of the greater MFA thesis project, Urban Acres. Advised by: Carolina de Bartolo, Marc English, Brian Majeski, Jeremy Stout, and Aran Baker. Fall 2009, Academy of Art University, San Francisco, California. All rights reserved.

contents 12

Preface Lisa Hammershaimb

why living roofs?

16

Buildings Like Trees, Cities Like Forests Bill McDonough

24 Living Roofs Explained City of Portland Environmental Services

48 Living Roofs Performance Study Bas baskaran and karen liu

living roof stories 60 View From the Bridge lisa cunningham

68 The Residential Front Patrick Carey

84 A Rooftop Farm for the Future Cathy Erway

rooftop resources 92

Living Roof Quick Facts

98

Plant Resources

108 Regional Resources 112 About the Contributors 114 Bibliography

—Winston Churchill, former Prime Minister

We shape our buildings initially ; and from then on our buildings shape us.

—Freidrich Hundert wasser, Architect

When one creates living roofs one does not need to fear the so-called paving of the landscape: the built structures themselves become part of the landscape.

Preface Lisa hammershaimb My initial interest in living roofs and sustainable urban design had rather strange beginnings. About to begin a cross-country drive from Colorado to Chicago and feeling ill-prepared with reading material, my mom grabbed a stack of free magazines on my way out the door at a favorite local breakfast spot. The magazines contained the usual glossy images of beautiful mountains, remote fields of wildf lowers, and constant reminders that life in Colorado is much better than anywhere else in the world, immediately followed by slick realtor ads and enticing custom home-building information.

When not driving, I browsed through them uttering the appropriate superlatives at the soaring mountain vistas and brilliant f lowers and wondering yet again why I was heading out of the mountains and into an urban area for an extended period of time, when suddenly I stumbled across an article addressing how to make your home more “friendly and green.� The easy tips gave way to larger design and lifestyle changes in an effort to reconcile the ever shaky relationship between man, nature, and the built environment. Futuristic solar panels clad one home while sexy sculptural wind tubines towered over another. Both homes looked bold and powerful, proudly showcasing the triumph of cutting edge green technology.

And then in the next article I saw something that was a bit less f lashy. It was something that was not space age or sexy but rather was just a home covered with a meadow of grass, visually quiet and beautiful. It was a home that, in an effort to improve insulation, absorb runoff, and create personal greenspace and a garden for the inhabitants sheltered below, had traded shingles for sedum and native plants and transformed an

14 / open space

overhead barren wasteland into something lush and serene.

As I read more about living roofs and the myriad of benefits, I was amazed and intrigued that something so simple, indeed so elementary as sowing seed and growing plants, could have such positive long-reaching results. In a world increasingly detached from nature yet obsessed with extolling its preservation, living roofs not only provide the results that make them a major player in the emerging world of sustainable design, but also provide the aesthetic connection to nature that we all crave. Needless to say I was a quick convert to the living roof movement.

When, during grad school, the opportunity arose for me to use my developing graphic design skills as “a way to promote positive change and reframe challenges and issues facing culture” through my graduate thesis project, a project promoting living roofs for urban spaces immediately made sense. Blending my skills in design with my passion for nature, Urban Acres: The Urban Living Roof Project was born.

This book is not intended as a living roof how-to guide or an exhaustive technical manual for creating and installing your own living roof. For those questions I recommend you contact one of the licensed living roof installers listed in the resources section at the back of the book or connect with one of the grassroots community education organizations that have been created across the country. Instead this book shares a broad overview of living roofs, a bird’s eye view if you will, and shares stories of a few buildings that have begun to open the way for a new urban landscape where structures do not isolate people from nature but rather remind us of the beauty that comes from living as a creature in part of an amazing natural world. Living roof also go by other names such as “green roofs” or “ecoroofs.” Though there is no one right name, I have chosen to call them living roofs because to me this name ref lects what they do with the most accuracy. Plants, when applied to the surface of a roof bring life to an unexpected place, thus making it living. The ultimate goal of Urban Acres is to transform our rooftops from barren to lush and in so doing transform what it means both to have a roof and to connect with nature in the context of an urban environment in a way that is deeply meaningful.

why living roofs?

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we must learn to ask more of our created enviroment. sustainable design must become the normal building scheme for harmony with nature.

Buildings Like Trees, Cities Like Forests Bill McDonough When the architect and theorist Le Corbusier imagined the future of cities from the vantage of the early 20th century, he foresaw a new industrial aesthetic that would free design from the constraints of the natural world. For Le Corbusier, the city was “a human operation directed against nature” and the house was “a machine for living in.” He imagined architecture worldwide shaped by a “mass production spirit.” The ideal: “One single building for all nations and climates.” Le Corbusier’s friends dismissed his futuristic ideas. “All this is for the year 2000,” they said.

It seems they were right. In many ways, our world is LeCorbusier’s world: From Rangoon to Reykjavik one-size-fits-all buildings employ the “engineer’s aesthetic” to overcome the rules of the natural world. As uplifting as that might be for the spirit of LeCorbusier, it is becoming more apparent all the time that buildings conceived as mass-produced machines impoverish cultural diversity and leave their inhabitants cut-off from the wonders and delights of nature.

But what if buildings were alive? What if our homes and workplaces were like trees, living organisms participating productively in their surroundings?

Bringing value to the spaces they inhabit?

Imagine a building, enmeshed in the landscape, that harvests the energy of the sun, sequesters carbon and makes oxygen. Imagine on-site wetlands and botanical gardens recovering nutrients from circulating water. Fresh air, flowering plants, and daylight everywhere. Beauty and comfort for every inhabitant. A roof covered in soil and sedum to absorb the falling rain. Birds nesting and feeding in the building’s verdant footprint. In short, a life-support system in harmony with energy flows, human souls, and other living things. Hardly a machine at all.

This is not science fiction. Buildings like trees, though few in number, already exist. So when we survey the future-the prospects for buildings and cities, settled and unsettled lands-we see a new sensibility emerging, one in which inhabiting a place becomes a mindful, delightful participation in landscape. This perspective is both rigorous and poetic. It is built on design principles inspired by nature’s laws. It is enacted by immersing

Buildings like trees, though few in number, already exist. So when we survey the future—the prospects for buildings and cities, settled and unsettled lands—we see a new sensibility emerging, one in which inhabiting a place becomes a mindful, delightful participation in landscape. This perspective is both rigorous and poetic. It is built on design principles inspired by nature’s laws. It is enacted by immersing oneself in the life of a place to discover the most fitting and beautiful materials and forms. It is a design aesthetic that draws equally on the poetics of science and the poetics of space. We truly hope it is the design strategy of the future.

the human leaf If one unpacks the compressed verse of Einstein—e=mc2 —one finds poetry, beauty, the dynamic structure of the universe. Following Einstein’s inimitable lead, we see in e=mc 2 a kind of design koan. e is the energy of the sun-physics and planetary motion. m is the mass of the earth-chemistry. When the two interact at the speed of light, biology flourishes and we celebrate its increase-the growth of trees, plants, food, biodiversity and all the cycles of nature that run on the sun. Good growth. And when human systems support ecological health, that’s good growth too.

Applied to design, the laws of nature give architects, designers and planners a set of principles that allow them to articulate in form a building’s or a town’s connection to a particular place. They allow us to create buildings that make the energy of the sun a part of our metabolism and apply it to positive human purpose—the building as “human leaf.”

The principles, illustrated by the life of a tree, are basic.

einstein’s principle illustrated

b

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sun energizes earth

b earth grows plans

plants renew life

Use current solar income Living things thrive on the energy of the sun. Simply put, a tree manufactures food from sunlight, an elegant, effective system that uses the earth’s only perpetual source of energy income. Buildings that tap into solar income—using direct solar energy collection; passive solar processes such as daylighting; and wind power, which is created by thermal flows fueled by sunlight-make productive and profitable use of local energy flows.

Celebrate diversity “The tree” provides not just one design model but many. Around the world, photosynthesis and nutrient cycling, adapted to locale, yield an astonishing diversity of forms. Bald cypress, desert palm, and Douglas fir suggest a range of niches. The hundreds of tree species within a single acre of Southern Appalachian forest suggest the diversity of a single region. Architects and planners, applying a diversity of design solutions, can create buildings and cities that fit elegantly and effectively into their own niches.

Waste=Food The processes of each organism in a living system contribute to the health of the whole. A fruit tree’s blossoms fall to the ground and decompose into food for other living things. Bacteria and fungi feed on the organic waste of both the tree and the animals that eat its fruit, depositing nutrients in the soil in a form ready for the tree to take up and convert into growth. One organism’s waste becomes food for another. Applied to architecture, these cradle-to-cradle nutrient cycles can serve as models for the design of materials and building systems eliminating the concept of waste. Materials designed can be either safely returned to the soil or re-utilized as high-quality materials for new products.

kinship with all life As architects and planners explore these principles—what amounts to a new conception of design—they will become more adept at creating fit and fitting spaces for human habitation.

New benchmarks will emerge. Rather than overpowering nature or limiting human impact, good design will affirm the possibility of developing healthy and creatively interactive relationships between human settlements and the natural world.

With new benchmarks will come new practices, and a design process that is now rare will, we hope, become the norm. Design teams in many regions would begin with an assessment of the natural systems of a place—its landforms, hydrology, vegetation, and climate. They would tap into natural and cultural history; investigate local energy sources; explore the cycles of sunlight, shade and water; study the vernacular architecture of the region and the lives of local fauna, flowers and grasses.

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a living roof integrated into a Toronto office building proviides huge benefits for its inhabitants and enhances the views from surrounding buildings.

learning from a tree

use solar income

celebr ate diversit y

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waste=food

Combining an understanding of building and energy systems with this emerging “essay of clues,� designers would discover appropriate patterns for the development of the landscape.

Building materials would be selected with the same care, chosen only after a careful assessment of a variety of characteristics, ranging from their chemistry to the impacts of their use, harvesting and manufacture. We might also expect to see the industry-wide pooling of architectural products as builders begin to create closed-loop recycling systems to effectively manage the flow of materials.

With this emphasis on sustaining and enhancing the qualities of the landscape, architectural and community designs would begin to create beneficial ecological footprints-more habitat, wetlands and clean water, not fewer negative emissions.

In this new landscape, we would see buildings like trees, alive to their surroundings and inhabitants, and cities like forests, in which nature and design create a living, breathing habitat.

Vital threads of landscape would provide connectivity between communities, linking urban forests to downtown neighborhoods to riparian corridors to distant wilds. Cities and towns would be shaped and cultivated by an understanding of their singular evolutionary matrix, a new sense of natural and cultural identity that would grow health, diversity and delight, and set the stage for long-term prosperity.

Changes such as these, many already afoot, signal a hopeful new era. Ultimately, they will lead to ever more places that honor not just human ingenuity but harmony with the exquisite intelligence of nature. And when that becomes the hallmark of good design, we will have left behind the century of the machine and begun to celebrate our kinship with all of life.

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(upper) a living roof transforms unused space into a green and breathing surface that both protects the building below and grows produce for neighborhood inhabitants. (lower) swiss chard and vegetables bring vegetable gardens up to the roof.

a living roof integrated into a Toronto office building proviides huge benefits for its inhabitants and enhances the views from surrounding buildings.

plants shelter animals

synergistic relationship acted out on a living roof

b

b b

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waste feeds microorganisms

plants protect soil

b soil anchors plants

b

microorganisms enrich the soil

Living Roofs Explained City of Portland Environmental Services Living roofs are living, breathing, vegetated roof systems that provide a sustainable alternative to conventional roofing. They are part of a growing world-wide effort to promote sustainable development and reduce negative impacts on air, water, energy, and the earth.

Cities encourage the use of living roofs as part of their efforts to promote sustainable development and protect their sewer infrastructure.

A living roof is a lightweight system of soil (growing media or substrate) and vegetation designed to be as self-sustaining as possible. A successful living roof is synergetic. The soil anchors the plant roots and supports plant growth. The plants protect the soil from erosion and heat gain. Roots and soil foster microorganisms that make the soil and plants healthier.

Water and sun feed the soil and plants. Plants photosynthesize and produce food for other species. The other species in turn produce waste matter that helps improve the soil. Living roofs are also known as ecoroofs, extensive greenroofs, or vegetated roofs.

Living roofs can be used on most types of commercial, multifamily, and industrial structures, as well as single-family homes, garages, and other facilities. Living roofs are suitable for both new construction and re-roofing of existing buildings, and can be located on both flat and pitched roofs.

Buildings are predominately made of wood, steel, brick, some form of concrete, or a combination of two or more of these materials. When properly designed, all of these materials are appropriate for living roof installations. Living roofs often enhance the structure and durability of the buildings upon which they are placed. Based on documented experience and studies, living roofs offer a number of important benfits that conventional roofs do not. In fact, conventional roofs cause many of the urban infrastructure problems that living roofs solve.

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intensive and extensive living roof examples and characteristics

intensive roof

extensive roof

b deeper soil

b shallower soil

b more expensive to build

b cheaper to build

b heavier weight

b lighter weight

b lower slope

b can have higher slope

b can support human activit y

b may have limited access

b require more maintenance

b require less maintenance

b retain more stormwater

b retain less stormwater

b have more diversit y

b have less diversit y

extensive and intensive living roofs There are two types of living roof systems—“extensive” and “intensive.” An extensive living roof weighs less than an intensive green roof. It generally has shallower growing material and heartier plants that require little maintenance. It also can be at a steeper slope. Intensive living roofs are the like gardens on the ground—with deeper growing material, more intricate or delicate plantings, and more maintenance needs such as irrigation and pruning. They have greater variety and because of the intensive nature of their plants, a less steep slope.

The type of rooftop you design depends partly on your interest in gardening and maintenance, and on the environmental benefits you may wish to achieve. Most importantly, you must evaluate the structural capacity of the building in order to assess your options.

rooftop container gardens A simple rooftop garden can also be created with planting containers, potted plants, and grow boxes. Whether on one-story structures or on skyscrapers, container rooftop gardens are havens with a charm of their own. For their owners, they provide private worlds in which to grow plants and escape the bustle of city life. All this, of course, is made possible with soil brought in and carried to the top of the building for the pots and boxes that comprise the rooftop garden. If you have ever seen a penthouse garden, you know what a feeling of space it gives, especially if the building is high. It is like being on a mountain top, with a panoramic view that on clear days seems limitless. It is not a permanent structure, as a living roof is, and as such can be created in a rental unit or when financial or structural issues make a rooted living roof impossible.

This kind of garden is the most common for homeowners to construct because they are relatively low in cost and easy to maintain. It can be an extremely effective way to grow fruits and vegetables in densely populated urban areas. Uncommon Ground, a restaurant in Chicago has the first certified organic rooftop farm that is created exclusively from built containers. Uncommon Ground is able to grow a significant portion of its required restaurant produce, providing diners with a more flavorful experience as well as food with very little transportation from plant to plate. A container garden provides the benefits of reflectivity, shade, and evapotranspiration.

On the negative side, when compared to a living roof system, it is not as effective at insulating, reducing stormwater runoff, or supporting bird and insect diversity.

For a new building project, the best time to consider a living roof is during the initial concept/schematic design phases. Even though the living roof is on top of the building, many building design elements need to be considered.

Many living roofs have also been installed on existing buildings throughout cities. The best time to consider a living roof for an existing building is when the roof needs repair or replacement, when considering seismic upgrades, or when considering building remodeling. Some building owners have installed living roofs on their existing roof membrane to extend the life span or have installed modified living roofs or even intensive rooftop gardens after taking into account the nature of their pre-existing roof.

Again, while rooted rooftops provide the most benefits, intensive rooftop container

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uncommon ground, a restaurant in chicago, has taken full advantage of their unused rooftop space and grows a large portion of their vegetables showing once again that open roofs mean open opportunities.

gardens also aid in stormwater management and rooftop membrane protection.

a living roof is best installed while the structure is being built. it is always important to work with certified living roof professionals to ensure that your roof performs the best it can and provides you maximum benefits.

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living roofs can turn any space into a garden. Here a small sun room attached to a london home blends seamlessly into the garden. the roof absorbs water and also has a rainbarrel attached to collect excess runoff.

living roof elevation and section

roof tr ays

fascia rafters

wall

foundation base

roof tr ays fascia

wall

foundation

It is important to determine the basic design concept, including analysis of the building structure and anticipated level of operations and maintenance (O&M) required for the ecoroof before starting the design process. Living roofs afford many options depending on the purpose of the roof. Building owners and designers may want a relatively utilitarian living roof that provides stormwater management and building insulation, while others may want their living roof to provide habitat for greater biodiversity, aesthetics, access for human use, or some combination of any of these.

Most buildings require roof access for operations and maintenance of mechanical units, window washing, and other activities. Access requirements should be identified during the design phase, and access paths of gravel or other inert materials provided. Where access is needed only occasionally, paths may not be required because the vegetation can tolerate some foot traffic. The living roof design should include provisions for

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it is vital to plan and create safe points of access on a living roof so you can easily tend to plants and perform maintenance.

storage of maintenance equipment and materials, especially for large buildings.

A successful living roof requires that all elements are well executed and work well together. These include design, construction, establishment, o&m plan, and o&m implementation. If any of these elements is poor, the project and certainly the roof may fail.

Living roofs weigh from 15 to 30 pounds per square foot (psf) saturated, depending on the vegetation and growth medium used. The building being considered for an living roof must be able to support this additional weight.

For new construction, the additional weight of the living roof may or may not require a more substantial structure. Design issues include the building’s foundations, rafters, posts, beams, decking, and other structural elements.

For existing buildings, needed structural upgrades may include additional decking, roof trusses, joists, columns, or foundations. Many buildings already have a 15 psf gravel ballast roof and are usually structurally sufficient to hold a living roof. One caution, if they are used in mixes, they will be subject to scour and blow-off. If a significant amount of these materials is used, gravel ballast (mulch) on top or vegetated mats should be considered in order to limit the scouring. structural loads for materials per cubic foot material

weight (lbs/cubic foot)

Water

62.4

Pumice

40

Silty Loam (dry)

70–75

Silty Loam (moist)

90–100

Silty Loam (saturated)

100–120

Perilite (expanded)

11

Concrete

150

Peat (dry)

24

Peat (saturated)

70

Gravel (dry)

105

Gravel (wet)

125

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living roofs are not limited to flat roofs. with proper materials and infrastructure, living roofs can have up to a 40 degree slope. living roofs most commonly have a 2 to 15 percent slope which allows for good drainage without putting too much vertical stress on the plants.

choosing the right living roof site and roof slope Slope is the angle of pitch of the roof plane. Slope affects the irrigation, plant material, and materials needed (e.g., lattice to prevent soil sloughing). Most living roofs are relatively flat, with slopes around 2 percent, although some are as steep as 40 percent. Because flat slopes have less sun exposure and less need for irrigation they work well for southern and eastern exposure. b Find True North

An ideal living roof in North America would have a north aspect (face north.) North is best to help reduce evaporation and solar exposure, which helps support vegetation.

A north-facing living roof may not require irrigation. ideal roof slope: 2 to 15 percent b Learn from the East

An eastern exposure is second best. Receiving morning sun, it still has longer periods of time away from direct rays slowing evaporation and helping keep the roof moist. ideal roof slope: 2 to 15 percent b Southwest is Not Best

Avoid any south and west exposures. Both receive the most intense and drying solar exposure and will require greater soil depth and irrigation to keep plants alive. ideal roof slope: less than 2 percent

choosing a membrane Modified Asphalt Membranes Modified asphalt, or bitumen, is generally asphalt material that has been improved with petroleum-based additives. It is a multi-layer system that comes in sheets, rolls, and liquid. Modified asphalt can be applied hot, cold, torched, or self-adhered. It can be laid loose or adhered to the roof deck.

Thermoplastic Membranes Thermoplastic membranes include pvc (polyvinyl chloride), tpo (thermoplastic olefin or polyolefin), and epdm (ethylene propylene diene terpolymer). These membranes are all single-ply systems that come in rolls or large sheets.

They can be laid loose or adhered to the roof deck. Many companies already manufacture waterproof membranes appropriate for living roofs.

insulation Building insulation is often associated with the ecoroof ’s waterproof membrane and is therefore important to consider at the early stage of design. Insulation can be placed in one of two placed either above the ceiling inside the building which keeps the insulation out of the way of the ecoroof or above the roof deck, under the waterproof membrane. The downside of the latter is that the insulation is often damaged during the re-roofing process.

root barriers Root barriers prevent vegetation roots from penetrating the membrane and causing leaks. The need for a root barrier depends on the waterproof membrane selected.

Consult the membrane manufacturer to determine if a root barrier is required for a particular product. Physical root barriers are made of dense plastic. The material is overlaid on the membrane and overlapped at the seams by fiveh feet or more. pvc,

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epdm, and tpo membranes act as the physical root barrier themselves.

a living roof installation is a multi-step process. the many layers come together to create a living habitat. this roof, on the penn charter school in philadelphia provides a huge amount of additional green space to the communit y and valuable habitat for local birds.

rooftop drainage methods

bb

b

slope

42 / open space

b

bb

b

gr avel

bb porous soil

bb

b dr ainage channel

drainage methods Slope The steeper the slope, the faster water drains. A slope of two percent or more will facilitate drainage off the roof and will minimize standing water, even with surface irregularities. At slopes greater than twenty percent, some sort of soil stabilization method is needed.

Gravel or Sub-Rock Layer This is perhaps the oldest drainage method for roof gardens and vegetative roofs. Since the advent of many plastic drainage products, gravel has been used on ecoroofs less often. Some living roof designers, however, are finding that gravel is sometimes still a preferred option.

Porous Soil Porous soil allows horizontal f low through the soil during storm events, and no other drainage material is used. When the soil is saturated, the stormwater f lows across the surface to the vertical drain. This approach has been used primarliy on small and medium size projects. The negative side of these soils is that stormwater management may not be optimum and summer irrigation needs may be higher Drainage Channels This approach uses a narrow gravel channel that runs along a contour of the slope and facilitates the f low of water to the drain. It is not a sub-layer; it can stand alone or be used in conjunction with a gravel sub-layer. Since most living roof soils are porous, the channel helps relieve water buildup during heavy rains.

It should be noted that some living roofs with river gravel support sedums without any

adequate dr ainaige is essential to living roof viatlit y.

irrigation. It is anticipated that stormwater management would be less.

growing plants Growth Medium (Soil) The growth medium is one of the most important components affecting the success of an ecoroof, but there is no clear answer about the best soils to use. Living roof plants can grow in many soils and conditions and different soils provide different levels of stormwater management. Most soils are prone to wind erosion when exposed. It is important to ensure good plant coverage or mulch to keep soil on the roof.

Soil Mixes Soil mixes used for living roofs vary. The average is a mixture of 75 percent mineral and 25 percent compost/organic with most of the mineral being pumice or expanded shale. Soil formulated specifically for living roofs is available, and hopefully soil companies will continue to research and develop the most sustainable blends.

Studies will continue to monitor performance and at some point will determine a minimum specification to ensure living roofs are performing adequately.

Soil Depth Deeper soils allow for greater moisture retention, building insulation, and vegetation support. For living roofs on new buildings, a depth of 4 to 6 inches appears to work well though deeper, if possible, is always better. For living roofs on existing buildings, soil depth can be from 3 to 6 inches depending on the structural capacity of the building.

Mulch A rock covering over living roof soil can retard evaporation caused by solar exposure and dry air from building vents. Sedums appear to prefer gravelly soils. Bark or wood mulch has the potential to blow off, burn, or decompose over time. Rock mulch has proven to be most effective in protecting soil and plants. River rock and

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a living roof is a synergistic combination of many forces.

large aggregate red cinder are great options.

installation methods Seeds Seeds can be used for many species considered to be appropriate for a living roof.

Wildf lower seeds are most often planted after the sedum plants. Careful attention to irrigation is required to ensure the seeds germinate and grow to their full capacity.

Cuttings/Sprigs These are small pieces of sedum and other succulents thrown evenly across the top of the soil. Cuttings usually require frequent light irrigation for 3 to 6 months to accelerate establishment.

Bulbs Bulbous plants have been installed successfully on many roofs. They include daffodils, onions, bluebells, muscari, and tulips. Bulbs are simply pushed 2 to 3 inches into the soil.

Plugs Plugs are small plants in 2-inch or smaller pots or sometimes in large trays. The plants are individually removed and planted with 12-inch spacing.

Pots These plants are grown in 4-inch or larger pots. When they have grown largers, they are removed from the pot and planted with 12-inch or greater spacing.

Hydro-seed/mulch Hydro-seeding has been done on a couple of projects, with some successes and some problems. Effective hydro-seeding has been done with marigolds and clover.

Vegetated Mats Vegetated mats are a sod-like approach to vegetation on living roofs.

Plants are grown in relatively thin soils that have been spread over a fabric-type of material. Some mats are grown similarly to turf sod and have only soil, not fabric. They produce a quick and easy living roof.

Trays A tray is a shallow container that contains soil and plants. It is rectangular or square, from 2 to 6 inches deep and 12 to 48 inches wide or long. Most trays are made of plastic; some are aluminum and some are bio-trays of coir fabric.

Heat that ref lects off building surfaces can damage vegetation. Living roof placement should be carefully considered before installation. Solar exposure that is related to aspect and slope is also very important to consider when designing an living roof.

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plugs provide an easy living roof solution.

water sources Water is vital to a living roof and all water sources should be considered early in the design stage.

Precipitation The ideal choice would be an ecoroof without need of water other than the precipitation that lands on it.

Shade (natural and applied) Many native and non-native plants can survive without irrigation if some shade is present. Shade can be provided by taller buildings that shade a lower roof, roofs with a north aspect, trees that cast shadows, parapets, and photovoltaics and other mechanical equipment. Rock mulch may also help to retard evaporation on the roof.

Non-potable Water (Condensate) Many buildings have air conditioning equipment that discharges water condensate. Some living roof projects are designed to capture condensate and rainwater, with potable water as a potential backup plan.

Potable Water Although potable water is readily available, it is desirable to limit use.

Many types of irrigation systems, both manual and automatic, are being used on living roofs. These include hand watering, back-yard sprinklers, commercial spray or stream heads on risers and pop-ups, large rotary heads, and various drip systems. Irrigation systems may not last for the life of an living roof and may require replacement or major repair over time. This is another reason to keep them simple and minimize their use.

To minimize water needs, early autumn is the best planting season. Contractors have often over-watered living roofs, especially during the plant establishment period. This

48 / open space

can damage succulents and other plants.

weeding Depending on the planting method, weeding and mulching may be needed during the establishment period and periodically thereafter over the life of the living roof.

The best approach is to be patient, watch the plants first, and then decide what to do.

Checking for undesirable weeds and trees should be done in late May or early June.

Most summers will be dry enough to inhibit weeds, unless the living roof is overwatered. In wet summers, weeds may come back after removal, requiring a second or even third weeding.

Pulling causes more disturbance to the ecoroof, and soil is often removed. It also removes the diversity of weed roots and microorganisms. Cutting disturbs the soil less and may allow many weeds to return from the base. If not watered, the base of many weeds die and can break down in soil. Herbicides or pesticides should be avoided at all costs as they can runoff and contaminate water systems and hurt other plants and insects that they come in contact with.

rooftop preditary plants b Large Roots

Small trees or plants with aggressive root structures will penetrate the membrane creating holes and leaks in the living roof. Tree saplings should be immediately weeded out.

b Dry Growth

Plants, such as certain tall grasses and herbaceous species that grow in abundance can dry out, and become a fire hazard. Dry growth should be immediately removed and rooftops should be constantly monitored for dry growth.

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even in fall and winter when the roof is not as green, living roofs retain their ability to absorb stormwater, insulate buildings, and provide bird and insect habitat.

living roofs can soften the harsh lines of urban building and bring color and life to unexpected places, enhancing views from other buildings.

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living roofs help divert urban heat islands that can form in large cities.

Living Roofs Performance Study Bas baskaran Living roofs not only add aesthetic appeal to the unused roof space that is available in most urban areas; they also provide many benefits. Living roofs can protect the roofing membrane from exposure to ultra violet radiation and hail damage. They can reduce energy demand on space conditioning, and hence greenhouse gas emissions.

If widely adopted, living roofs could reduce the urban heat island (an elevation of temperature relative to the surrounding rural areas due to the concentration of heat absorbing rooftops and pavements.)

Reducing the heat island effect would further lower energy consumption in urban areas. Living roofs can also be used as part of the stormwater management strategy in the urban area. Part of the rain is stored in the growing medium temporarily, and to be taken up by the plants and returned to the atmosphere through evapotranspiration.

Living roofs delay runoff into the sewage system, thus help to reduce the frequency of combined sewage overf low (cso) events, which is a significant environmental problem for many of the major cities in North America. Living roofs helps sewer systems cope.

summer urban heat island temperature effect

90 88 86 84

rur al

suburban

urban

suburban

82

rur al

temperature in farenheit

92

The plants and the growing medium can also remove airborne pollutants picked up by the rain, thus improving the quality of the runoff. In addition, green roofs can improve air quality, provide additional green space in urban areas, and increase property values.

Living roofs are found throughout many European countries such as France, Germany and Switzerland. They are rapidly gaining popularity across different parts of the world as well. In North America, Portland, Oregon has pioneered a cutting-edge incentive program many cities are copying.

The Clean Air Incentive and Discount Program encourages the installation of green roofs on commercial, industrial, institutional and residential properties, with the aim of reducing the stormwater runoff problem and relieving the loading on the sewage infrastructure. Many businesses as well as homeowers are taking advantage of the generous financial incentive. In Asia, Tokyo, Japan has initiated a new ordinance to install green roofs on new buildings with f loor space more than 10800 ft2 to mitigate the urban heat island effects.

the test site The National Research Council of Canada (ncr) has constructed the Field Roofing Facility in Ottowa. It provides an experimental roof area of about 800 ft2 representing a low slope roof with a high roof-to-wall ratio. The roof is divided into two equal areas separated by a median divider: a generic extensive living roof was installed on one side and a modified bituminous roofing assembly was installed as a reference on the other. The surface of the roof membrane (on both) is covered with light grey coloured granules, to avoid extremes in ref lection.

While the Green Roof have the same basic components up to the membrane level, it incorporates additional elements to support plant growth. In the first year of the study (2001), a wild f lower meadow was established in the garden and in the second year (2002), common lawn grass (Kentucky blue grass) was planted.

Both the Living Roof and the Reference Roof have been instrumented. The local meteorological data such as temperature, relative humidity, rainfall and solar radiation are monitored continuously by a weather station located at the median divider on the

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rooftop and an additional weather station situated approximately 160 ft from the site.

reference roof and living roof comparison

reference roof

living roof

b covered in light gr ay

b covered in dr ainage layer,

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waterproof membr ane and white gr avel

extensive growing medium and native vegetation

b 342 days over 86ºF

b 18 days over 86ºF

b 219 days over 122ºF

b 0 days over 122ºF

b high temper ature of 158ºF

b high temper ature of 91ºF

temperature overview An exposed roof membrane absorbs solar radiation during the day and its temperature rises. Light colour membranes are cooler because they ref lect solar radiation but dark colour membranes are hotter because they absorb much of the solar radiation.

Results show that the roof membrane on the Reference Roof experienced much higher temperatures than that on the Living Roof. The membrane on the Reference Roof absorbed the solar radiation and reached close to 158°f in the afternoon. However, the membrane on the Green Roof only remained around 77°f.

Heat exposure can accelerate aging in bituminous material, thus reducing its durability. Ultra violet radiation can change the chemical composition and degrade the mechanical properties of the bituminous materials. Although long-term durability data is not available from the study yet, the growing medium and the vegetation of the green roof can prevent the UV radiation from attacking the roofing membrane and minimize aging of the membrane from heat exposure, which might extend the life of the membrane.

temperature variance An exposed membrane absorbs solar radiation during the day and its surface temperature rises. It re-radiates the absorbed heat at night and its surface temperature drops.

Diurnal (daily) temperature f luctuations create thermal stresses in the membrane, affecting its long-term performance and its ability to protect a building from water infiltration. The membrane temperature f luctuation (daily maximum temperature– daily minimum temperature) of the Reference Roof and the Living Roof and the daily ambient temperature f luctuations have huge variance from cold to hot.

The Living Roof moderated the daily temperature f luctuations that the membrane experienced during early winter (November and December), while the membrane temperature of the Reference Roof followed the daily ambient temperature f luctuations.

This protection was somewhat dissipated during the accumulation of snow, and once heavy snow coverage was established both roofing membranes were protected from temperature f luctuations. The Living Roof significantly moderated daily f luctuations experienced in spring and summer.

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Living roofs absorb and reflect sunlight helping them cool the buildings beneath them.

The daily membrane temperature f luctuations of the Living Roof were consistently lower than the diurnal ambient temperature f luctuations. The exposed membrane in the Reference Roof experienced high daily temperature f luctuation, with a median of about 81°f. However, the Living Roof reduced the temperature f luctuation in the roof membrane throughout the year, keeping a median f luctuation of about 11°f only.

The energy efficiency of the Living Roof was slightly better than that of the Reference Roof in the fall and early winter as the green roof system acted as an insulation layer.

However, as the growing medium froze, its insulation value was greatly diminished.

Snow coverage provided excellent insulation to the roofing system and stabilized the heat exchange between the building and its surrounding. The snow coverage on the roof was not uniform in early winter due to the wind and the inf luence of the high parapet. Once snow coverage was established on the roof, heat f low through both roofs was almost the same.

The Living Roof significantly outperformed the Reference Roof in spring and summer (April to September). Solar radiation has a strong inf luence on the heat f low through the roof. The membrane on the Reference Roof, being exposed to the elements, absorbed solar radiation during the day and re-radiated the absorbed heat at night, creating high daily energy demand for space conditioning. On the other hand, the growing medium and the plants enhanced the thermal performance of the Living Roof by providing shading, insulation and evaporative cooling. It also effectively damped thermal f luctuations.

The average daily energy demand for space conditioning due to the heat f low through the Reference Roof was 6.0–7.5 kwh/day. However, the growing medium and the plants of the living roof modified the heat f low and reduced the average daily energy demand to less than 1.5 kwh/day—a reduction of over 75%. Note that these values were due to the heat f low through the roof only (400 ft2) and did not include heat f low through other parts of the building.

The plants and the growing medium in the Living Roof kept the roofing membrane cool by direct shading, evaporative cooling from the plants and the growing medium, additional insulation values from both the plants and the growing medium, and the thermal mass effects of the growing medium.

The Living Roof was found to be very effective in helping to keep the building significantly cooler in the summer when compared to the Reference roof.

All elements on a living roof working together have the potential to produce dramatically positive change in our urban spaces.

The membrane on the Reference Roof, being exposed to the elements, absorbed solar radiation during the day and re-radiated the absorbed heat at night, creating positive heat f low in the afternoon and negative heat f low in the early morning and evening.

The Living Roof significantly moderated the heat f low between the building and its surrounding through the roofing system. In the winter, data showed that once the snow coverage was established, the heat f low through both the Reference Roof and the Living Roof became the same as snow coverage provided good insulation and stabilized heat f low through the roof.

During the 22-month observation period, the Living Roof reduced 95% of the heat gain and 26% of the heat loss as compared to the Reference Roof, with an overall heat f low reduction of 47%. Since an extensive green roof was more effective in reducing heat gain than heat loss, and Ottawa is in a predominantly heating region, it is expected that its effectiveness will be even more significant in warmer regions.

Observation from the Field Roofing Facility showed that a generic extensive green roof with 150 mm of growing medium could reduce the temperature of the roof membrane significantly in the summer. The exposed roof membrane on the Reference Roof was recorded to reach over 158째f in the summer but that under the Living Roof rarely reached over 86째f. Also the Living Roof modified the temperature f luctuations the roof membrane experienced, especially in the warmer months. The median daily temperature f luctuation of the membrane on the Reference Roof in spring and summer ranged from 81째f, however, the Living Roof reduced the temperature f luctuation to 11째f. The Living Roof also significantly moderated the heat f low through the roofing system in the warmer months. This corresponded to a reduction in energy needs of over 75%. Living Roofs can moderate heat f low through the roof through shading, insulation, evapotranspiration and thermal mass effects. This reduces the energy

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demand for space conditioning, most significantly in spring and summer.

living roofs truly have the power to transform unused open space into something beautiful.

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living roof stories

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living roofs are bringing health back to places once considered toxic.

View From the Bridge lisa cunningham Long Island City, just across the East River from Manhattan, has been one of those up-and-coming neighborhoods for more than a quarter-century. Despite its proximity to midtown, the once heavily industrial area has been slow to transform itself. Due to air pollution, a lack of green space, and heavy traffic over the Queensboro Bridge, it took nearly two decades to see an uptick in residential and nonindustrial work spaces.

But a tipping point has finally been reached, and environmental advocates believe the neighborhood could—over the next 20 years—become a model for urban living roof development and neighborhood transformation.

Silvercup Studios is most famously home to Tony Soprano; since last July the former bakery, located next to the Queensboro Bridge, also became the site of New York’s largest largest roof. In 2002 landscape architect Diana Balmori conducted a study of the city’s rooftops to identify the best area where living roof construction could have an impact not just on an individual building but an entire neighborhood. The study revealed that Long Island City would be the most promising neighborhood for clustering these environmentally friendly roofs, which help clean the air, reduce storm-water runoff, lower energy consumption, and ultimately reduce the heat caused

the queensboro bridge forms a divide between the glamour of manhattan and the industry of long island cit y.

by urban congestion.

There is enough suitable f lat roof space in Long Island City to cover more than 26 million square feet with living roof technology—or 667 acres, nearly the size of Central Park.

Known as pancake roofs, the countless f lat-topped warehouses were mostly built before 1955, when structures were generally overengineered; therefore they can withstand rooftop vegetation without additional support. Long Island City is in serious need of greening: it has one of the lowest percentages of parkland per acre of any neighborhood in New York, and the area around the bridge is referred to by locals as “asthma alley.”

“If you aggregate lots of buildings with living roofs, you can lower the heat-island effect,” says Balmori, referring to the heat-trapping properties of asphalt, concrete, and black tar, which raise the temperature of dense urban areas. “I really think that is where the ecological contribution is going to be—creating microclimates. How you shape a building, how you place it on a street, what kind of shadows it casts, what types of vegetation you put where: it all contributes to the microclimate.”

If Long island City could convert all flat roofs to living roofs, they would acquire an area of green space almost as large as Central Park. Climate and quality of life would improve dramarically. With city incentives and public education this lofty goal is very attainable.

Upon completion of the study, Balmori made a presentation to the Long Island City Business Development Corporation, a nonprofit neighborhood improvement organization. Her idea was to develop a demonstration project with high visibility, but she needed committed partners to make it come to fruition. As a longtime contributor to the Environmental Action Coalition, Stuart Match Suna—cofounder of Silvercup Studios along with his brother Alan (both are trained architects)—was immediately interested in Balmori’s proposal. Having built a duplex on the Silvercup site, where he lived for ten years and tended to a roof garden, Suna was well aware of how polluted the air could get, especially on hot summer days, and the extent to which greenery can mitigate extreme temperatures. He made Silvercup available as the demonstration site and offered to pay for the necessary architectural and engineering studies to achieve optimal roof performance.

The green-roof partners then secured a $500,000 grant from Clean Air Communities—a local organization devoted to reducing air pollution in New York’s low-income neighborhoods—to fund the design, construction, and plantation of the roof, which was undertaken last summer at an auspicious time. Donning wide-brimmed hats, landscapers with Greener by Design planted the Silvercup roof just as the city was experiencing stif ling temperature spikes and breaking records for electricity consumption. “The need

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for green-roof technologies couldn’t have been more striking,” Suna says.

The living roof system on Silvercup is a modular one built by GreenTech, a company based in Roswell, Georgia, which donated a third of the modules for the project.

Unlike plantings directly on the roof—a more common type of green-roof system—the interlocking modules can be moved and replaced. Covering 35,000 square feet required 1,500 modules filled with a lightweight soil and then planted with 20 different varieties of sedum. Sedum is heat and drought resistant because it retains a high percentage of water in its shallow root system. Therefore it absorbs and holds more rainwater, reducing storm-water runoff and minimizing landscaping maintenance. Irrigation is needed to get the plants established, but they eventually become self-sustaining.

“We call the green roof the fifth facade of the building,” Balmori says, “because it can be very pleasant to look at from the surrounding buildins and the Queensboro Bridge. The roof can make all the difference in a building.”

A living roof is clearly an ecological workhorse rather than an aesthetic amenity like a garden, but that’s not to say it can’t be attractive. The plants were chosen and arranged by Balmori, and then the modules were interspersed with panels of brightly colored fabric to accentuate the yellow, red, and blue foliage. Along with the giant Silvercup sign visible from the Queensboro Bridge, the colored panels attract the eyes of motorists to the living roof.

While energy savings as a result of the insulating properties of green roofs are not likely to be significant in tall buildings with small footprints in Long Island City— where buildings are low and f lat—conservation is expected to be significant. A similar control study conducted in Chicago in 2003 showed that green-roof temperatures were 19 to 31 percent cooler during peak daytime hours in July compared with those on a conventional roof. What is expected to be even more significant, however, is the difference in storm-water runoff. The same study demonstrated that a green roof absorbed nearly half the water from a downpour.

Since the benefits are realized by the community at large, green-roof proponents strongly favor government incentives to stimulate property owners to both retrofit green roofs on existing buildings and install new ones. Stress on the city’s sewer system is reduced when rainwater is absorbed by greenery rather than being discharged into the system. Because so much of Long Island City is paved over, the sewage system gets overwhelmed, resulting in back-ups that cause raw sewage to be discharged directly into the East River after heavy rain.

Government incentives might include a tax credit, density bonuses, and an expedited building-permit process. But one question remains: Would that be enough to entice developers and property owners to undertake what is—in the most narrow view— expensive insulation? Chicago has more green roofs by far than any other American city. Like an urban canopy, more than two million square feet of greenery is or soon will be planted on rooftops. That is roughly 49 acres, or equivalent to the entire historic Greenwich Village neighborhood of New York City.

But the vast majority of Chicago’s green roofs are being installed because the city requires them. Any developer that receives financial help from the city must have a green roof, as determined by a complex formula. Mayor Richard M. Daley—in his fifth term in office and known for his autocratic style—can push through whatever regulation he wants. No New York mayor will ever have that much power, let alone use it on behalf of the environment, because developers won’t tolerate it. “I would be reluctant to require them,” Suna says when asked about applying Chicago’s regulations here. “That would make New York City that much more expensive, which isn’t good for the economy or the environment.” And that is perhaps where even the most enlightened property owners and environmentalists part company.

“Our overarching goal is to quantify the benefits of green roofs,” says Leslie Hoffman, executive director of Earth Pledge, “so that building owners, developers, and ultimately city, state, and other government officials can understand where to implement them, what the return on investment is, and ultimately depending on where the benefits are, who should pay for green-roof implementation.”

“In some cases it might be appropriate to have them partially required by building owners,” Hoffman continues. “But if the savings in storm-water treatment is significant enough, the city’s department of environmental protection should provide major incentives; because when you have a whole community of green roofs, everyone

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will benefit. That requires a little more than just enlightened self-interest.”

silvercup living roof installation creating the grid

planting

The 35,000 square-

The rooftop was

foot green roof was

planted with 20

created with 1,500

different varieties

interlocking GreenTech

of sedum.

roof modules.

installation The roof offers great views of the Queensboro Bridge and Manhattan.

filling the grid A soil mixture of lightweight expanded shale and organic material was prefilled into each module. planting A piece of small biodegradable fabric was laid on top to protect the plants from being uprooted by wind.

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the silvercup studio living roof is just the beginning ot a new season ur ur an renewal that will reviatlize many of new york cit y’s most polluted areas.

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residential lving roofs have the potential to increase both beaut y and performance.

The Residential Front Patrick Carey Residential roof surface represents an area that is approximately eight times greater than commercial roof surface. Residential development square foot per square foot is responsible for more deforestation and reduction of aerable land than commercial development. Residential development is generally closer to riparian waterways and has a more dramatic effect on them than commercial development.

Every benefit claimed for green roofs can be multiplied by at least eight times if applied to the residential market. Yet available green roof systems are targeted strictly for the commercial market, thus pricing them out of the reach of over 80% of the potential greenable roof area. This should definitely not be so.

What follows is a discussion of the factors that impede the inclusion of this residential market and strategies to break down these barriers. Living roofs, to bring change that is lasting and effective, must transform the residential roofing sector. In one form or other green roofs have been in existence for thousands of years. However, it is their latest reincarnation in Europe dating from the 1960’s that has transformed a practice into an industry. Relatively recent accelerations of urban density, global warming, shrinking government budgets, and increased legislation to abate environmental damage and conserve resources have all shed a brighter light on the benefits of green roofs.

European companies like ZinCo, Optigrun, Optima, Famos, Soprema, and EriscoBauder led the way in terms of developing green roof systems. American waterproof membrane specialists like American Hydrotech, Garland, and Sarnafil allied themselves with these Europeans in order to provide a green roof product to the American market.

It was a market that was getting increased attention because of the ecological promise and the novel image of green roofs.

Architects have traditionally used plants to soften the hard lines of their projects.

Now landscape architects find a new province to assert expertise. Civil engineers find new ways to address issues like storm water abatement, energy conservation, waste reduction, urban heat island phenomena, as well as air and water treatment.

Environmentalists are enthusiastic about urban reforestation and wildlife habitat. But, each step along this path of growing enthusiasm is made with blinders on. It appears as if all the members of the chorus read from only one text, commercial development.

This is the current state of affairs. However, the vast majority of roof surface is being ignored. Look at any zoning map of any city in North America and compare the area taken up by single family residential construction with that of commercial construction.

You will find that single family residential roof surface dwarfs commercial roof surface by a factor of at least five to one.

The fundamental element of the residential market is the individual home owner. To change the perspective and the market circumstances of the living roof movement can make the difference between green roofs being an experimental curiosity to a significant force to heal our planet.

In addition to its much larger roof production, residential development is more responsible for far more deforestation, conversion of untilled or tillable soil into building developments, and is generally in closer proximity to riparian waterways than commercial development. So, square foot for square foot, residential roof area has more developmental impact than that of commercial development. Every promoted benefit of green roofs could be multiplies by a factor of six if the residential market were seriously addressed.

Public expense for stormwater infrastructure, public expense for solid waste, and the resources devoted to residential cooling and heating, the livability of neighborhoods, interior acoustics, air filtration, and wildlife habitat could all be radically more affected with the greening of this vast resource. Currently there is no market for residential green roofs. Therefore, there is no list of tried and true strategies and tactics to produce one. Producing a significant change in this market is a very complex endeavor. It involves a strategy that is as broad as the full range of inf luences on this market and tactics that are as varied as each element of it.

The residential market is a polyglot of frequently conf licting codes and regulations.

Contractors in this market are for the most part non-union and are held to less stringent training and installation standards than those of the commercial sector. Green standards in the residential market are less stringent and have no teeth. Incentives offered to home owners or residential builders are usually less compelling than those

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in the commercial market.

Though this is the case, paradoxically there is eveidence to prove that homeowners are very interested in the sustainable design movement. Denver, after spending $500,000 on an education campaign to encourage sustainable housing construction found that sustainably constructed housing was outselling comparable unsustainably constructed housing by 50%. The Denver project used every opportunity to piggy back on to every event, every program, and every publication it could to get its idea across. Green roofs are rarely mentioned as a residential roofing option, and home owners are at the mercy of their construction market ignorance. There is enough information out there for any home owner to become well informed. But this information is not coordinated and the home owner lives in a world that screams: junk mail, junk email, screaming headlines, truck loads of pamphlets, reams of f liers, a galaxy of web sites all conspire to distract more than inform. A simpler message with a simpler approach is a more efficient strategy and these messages must be coordinated instead of competing for attention.

home sweet home: residential living roof benefits b Individual Stormwater Management

Roofs can absorb most of the rain that falls on them, thus reducing loads on residential sewer and stormwater systems. b Neighborhood Livability

Many studies have shown that green space has a positive impact on mental health. Living roofs bring green space to overlooked areas and improve the view from upper floors. b Interior Acoustics

Living roofs help muffle outside noise that might be intrusive, makeing a home more soundproof and quiet. b Air Filtration

Living roofs cleanse the air surrounding them through photosynthesis. This means the air that flow in windows or through HVAC system is less polluted and more healthy. b Wildlife Habitat

Birds, bees, and butterflies that are often diplaced during urban building projects flock to living roofs.

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plugs provide an easy living roof solution.

residential market development b Allow controlled expansion into residential market.

Commercial vendors can open their doors to certain residential contractors for traning in the use of their products to beomce approved contrators. b Develop specific residential roofing product .

Conscisouly place reseach and funding toward the creation of a resonably priced, effective, residential living roof. b Free up components of existing roofing system for residential use.

Create materials in smaller sizes and quantities. Keep quality consistent with commercial standards but accessible to the residential market. b Create a fund that all commercial vendors pay into to shrink the gap between commercial

and residential living roof sectors.

Require all companies to contribute to a research and development fund so that residntial

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with proper incentives and accountabilit y the residential living roof market can flourish.

needs may be adequately met.

One model that is useful is that of the news media. Newspapers, radio, and television all have nationally syndicated news sources as well as local news sources. A green roof information network could provide the same kind of vehicle with large sources of concentrated information, leaving regional specialization up to regional information sources. The efficiencies of this kind of system are proven. Redundant information will be minimized and resources from this can be devoted to improvements in quality versus mere quantity. This kind of information strategy will perform one very crucial task, to make information more understandable and thorough for the consumer.

Everyone else along the line will be paid in some way for the risk the consumer is about to make and this risk must be recognized and applauded. Every element of the picture is using the consumer as the market development tool. And to the extent the consumer helps to create a market from which all will benefit, that gesture must be supported.

This is the single most important part of this puzzle, the point of sale. For that sale to be possible on a large scale the individual consumer must be informed and the message must be organized and accessible.

commercial green roof industry and business community There is a litmus test that can be given to any green roof system vendor, designer, assembly part provider, or advocate. This is simply to ask the question “Of the roofs that are built, how many can your system or company supply a green roof for?� Keep in mind that residential roof surface comprises approximately 80% of all roof surface produced. If you can only provide for the wealthy, you fail. If you can only provide for commercial roofs, you fail. If you are making no attempt to support the residential green roof industry beyond pursuing profits for your own company, you fail. Those who fail have no legitimate right to claim they are environmentally progressive. Their activity in selling a product or service has no more merit than anyone else trying to sell their wares, whether they be green roof systems, or steak knives. The environmental benefit of their product is incidental to their activity, not the focus of it. There is a deeper meaning to ecology than profit motive and growing market share.

A residential green roof industry cannot survive on subsidies, grants, and volunteerism.

Until skilled and knowledgeable people can make a living from designing residential green roofs, no such industry will develop. Any progress in the market of residential green roofs ultimately benefits the commercial companies in that it will provide yet another market for their products and a source of installation expertise for its business.

government sector and incentives Governmental organizations are given the role of serving the public good. The resources they can bring to bear are tremendous, in terms of technical expertise, funding, public education, and establishment of regulations and incentives. However, each culture perceives the public good with different perspectives. Policies that have worked well in promoting progressive goals in one culture may appear to be draconian when applied to a culture that prizes individual freedom over collective responsibility.

Government organizations are not monolithic and frequently compete for turf. Their power to regulate, promote , and educate is a critical element in this over all strategy.

When I go to the City of Seattle and ask for a green home remodel guide, I get several brochures covering different aspects of home renovation. One of these brochures covers roofs. In it there is a two page explanation of residential green roofs. This is one small example of the legitimizing power of governmental recognition on the local level.

The availability of government funding is less an issue than the ability of green roof advocates to focus their attention on a few specific projects that can then produce evidence for more leverage. Green roofs for residential spaces must be legitimized in the eyes of the public.

In the past there have been a number of governmental programs to address weatherization issues from the standpoint of energy savings. Let’s say that an innovative settlement from a Supplemental Environmental Project negotiation is used as seed money for a Habitat for Humanity housing development. Supplemental funds come in from the Endangered Species Act, for wild life habitat. More comes in from the Clean Water Act. The local solid waste authority allows for some funds for materials that will stay out of the waste stream longer. Some green roof vendors donate parts of their assemblies, and local tradesmen donate their skills at installation. The result is an example that can be demonstrated. The second project will be easier. Does this sound like a long shot?

The truth is that each of these elements has been used to either achieve or promote a residential green roof project. But the door is open. Programs exist within hud, the epa and both the national and state levels and at the city levels to make demonstration

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projects work.

living roof incentives Policies to facilitate green roofs take a variety of forms, from density bonusings and fasttrack permits to tax credits and low-interest loans. All incentives help make living roofs more accessible and ultimately benefit communities. b Density Bonus

A program that allows developers to increase the floor area of a structure beyond existing zoning limitations when they implement green roofs. b Fast-Track Permitting

Permits are reviews in a matter of weeks rather than the months as it usually takes. b Green Space Allocation

Green space allocation is a regulatory measure used by governments that sets a minimum green space requirement depending on the lot size or occupancy of a new building. The municipality may allow the builder to meet the green space requirement by adding a green roof or by contributing to a fund that will be used to support green roof development. b Grants/Direct Investment

Direct investments are monetary incentives used to encourage implementation of green roof infrastructure. Direct investments are usually grants given by a funding agency (e.g., governments, non-profit foundations) with the condition that certain specifications or requirements are met and maintained. There is a growing number of government and nonprofit funds for which green roofs can now qualify. b Low-Interest Loan

The purpose of a low- interest (or interest-free) loan is to encourage investment in green roofs by lending the building money to help cover the extra costs involved in installing one.

Such loans are usually made by the municipality, utility, or a non-profit foundation and the principal is repayable over a specified period, such as ten years. b Tax Credit

Tax credits are financial incentives that reduce the amount of tax owed if a building owner contributes privately toward certain public goals. New or renovated buildings that conform to a specific standard, such as installing a green roof or other green building technologies, may receive a credit for a portion of their property tax.

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overlooking manhat tan the 6,000 square foot greenpoint, brooklyn farm brings fresh produce into the neighborhood for thousands of new yorkers.

A Rooftop Farm for the Future Cathy Erway A rustic scarecrow looms before the skyline of Manhattan’s midtown skyscrapers.

Under its watch lie more than 30 varieties of vegetables, fruits, f lowers and herbs on a rooftop in Greenpoint, Brooklyn. But its real scarecrows, the overseers of this rooftop farming project, are Ben Flanner and Annie Novak. I asked if they’d had any problems with pest.

“Lately, we’ve just begun getting some bugs. Both good and bad bugs. But even if they’re the bad ones, bugs are a good thing, because it means that they’re beginning to recognize that there’s an ecosystem here,” Novak replied.

The bugs are taking notice, and hopefully the general public soon will, too. Similar in mission to the New York Sunworks Science Barge project, in which the nonprofit forged a viable ecosystem on a raft on the Hudson, Eagle Street Rooftop Farm is further proof that agriculture can thrive in the unlikeliest of places.

On top of an industrial building overlooking the East River, just a stone’s throw from the Pulaski Bridge, sits the 6,000 square foot urban farm. The farmers hired a crane to pour 150,000 pounds of soil onto the roof and created an irrigation system to distribute the wealth of water. A cache of seedlings ready to be transferred to the soil on the roof sits just adjacent to the rooftop, grown from seeds purchased from organic seed savers like Seed Savers Exchange. A beehive has been set on another neighboring rooftop, and on the day I visited the farm, so did a local beekeeper who was excited about lending her expertise to the project. There was talk of building a coop to hold ten or so chickens on the roof. All told, however, the directors cite a modest budget for starting their project.

Last November, Ben Flanner read an article about Chris Goode in New York Magazine, and how he’d built several green rooftops in New York City, including his own in Soho. Then working in an office for eTrade, Flanner had been devouring books about farming all winter, and knew he’d wanted to do “something with it” that summer.

The two mens’ dreams came together after Flanner contacted Goode about starting a rooftop gardening project. They eventually found an industrial warehouse on Eagle Street willing to host the rooftop farm. Owned by Broadway Stages, its cavernous interior is frequently rented by the film industry for movie sets. For a partner, Flanner was constantly referred to Annie Novak, a farmer at Evolutionary Organics.

Both originally from the Midwest—Annie, from Chicago, and Ben from Milwaukee— the two were inspired by the urban farming activity there. “Chicago is a great place for apiaries,” said Novak, who estimates there are over 3,000 are present in the windy city.

While Novak has had rigorous experience in farming and farm education (she is also a Children’s Gardening Program Coordinator at the New York Botanical Garden in the Bronx, school gardening programmer with Slow Food USA, and runs the workshop Growing Chefs), Ben cites no farming experience, “ just passion.” He’d debated splitting his time between his office job and running the rooftop farm before quickly

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chard thrives on a rooftop farm and requires only simple drip irrigation.

realizing the demands of the farm.

on the house: the urban rooftop farming movement They’re not likely to replace the large-scale farming anytime soon, but rooftop agriculture projects are sprouting all over the world these days. The basic idea is brilliant: there’s a huge demand in urban areas for fresh produce, particularly organic goods—but land costs in urban areas make urban farming completely nonsensical from an economic point of view. There’s one patch of land that’s usually not being used, however—the rooftop.

Three ways of doing rooftop gardening: b Container Gardening

The rooftop is used as a handy place to have lots of containers for growing smaller crops. ideal crops: assorted herbs, tomatoes, assorted small lettuce varieites, b Agricultural Living Roof

The living roof is planted in crop rows, just as a farmer’s field would be on ground-level. ideal crops: chard, kale, zucchini, eggplant, tomatoes, peppers, mushroom, onion, potatoes, wheat, amaranth b Hydroponic System

Hydroponic systems dispense with the need for soil, which is tremendously heavy, making them more practical for rooftops that cannot bear a significant load. Though not as aesthetically pleasing as the other two systems, they provide huge yields in produce.

It was a sunny Memorial Day when I first stepped atop the rooftop farm. On it were two women who were volunteering that day, and throughout the next hour or so, several more volunteers would pop up. The rooftop’s crops were divided into two neat sets of rows about 100 feet long and 60 feet wide, with a wood chip-strewn walking path along the midsection and in between each row. The volunteers had just directsown radishes that morning. The directors estimate that close to 100 people have come through the farm to help out, going through one whole crop in a day, like radishes or scallions—many of which, according to popsicle stick-sized markers planted before each row, were only transplanted to the soil about one week ago. They looked almost ready to eat.

Taking a languid break, the farmers discussed inter-cropping the lettuces with tomatoes, so that the tall tomato plants would provide shade for its neighboring crops.

Or at least, that’s what I thought I heard. Novak answered my hapless question to clarify this point with a breathless explanation on the plants just at my feet: because lettuces are one of those plants that go to f lower when it gets too hot, and going to f lower early will spoil the harvest, the tomatoes are inter-cropped for shade, but that’s not the case with the pepper plants that are inter-cropped with the radishes over in the next row, they’ve been put in the same bed because radishes take 35 days to harvest while the peppers take much longer, so once they’re done new crops can be put in its place, maximizing the rooftop space.

“We want to teach as many people as possible,” said Novak, taking a seat along a bench of volunteers. “We believe so strongly that rooftop farms can bring so many positive benefits to the city and we want everyone to learn about their potential.”

Without all the enormous response they’d received from various friends and volunteers, none of it could have been possible. In their call for volunteers last week, twenty people responded, out of the forty people on the email list. Both of the volunteers I chatted with had heard about the project at the Brooklyn Food Conference, too—Bruni Torras, who’d worked at Added Value farm in Red Hook last year, and Betsey McCall, who manages Murray Hill Greenmarket and teaches yoga.

Learning how to grow plants can be intimidating for a lot of people, Annie observed, “because it’s a living thing and you can kill it. But just with experience you’ll get to watch how things grow,” she explained.

Once they’re ready to harvest, the group plans to provide local restaurants and other community organizations with their crops. But only very local ones—they plan to transport everything they grow by bike. Nearby Greenpoint restaurants might be in luck, like Anella, where the group often picks up compost scraps from. The Eagle Street Rooftop Farm might also set up a stand for passer-by customers later in the summer. Ben plans on growing some hops for Sixpoint Brewery soon.

At first, Novak admitted, she’d hoped the rooftop had been smaller. Now, she wishes it were 100 times bigger: “We could be growing so much more.” It’s all a learning experience, though. A diverse ecosystem is the first goal. Hopefully the lessons

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learned will become useful for later rooftop farmers.

That is the ultimate goal of its founders, setting the mold for future rooftop farms to come. While we can all use more freshly grown produce in the city, the projects stands a testament that it can simply be done.

“I just want it to be possible, and something that’s done all over,” said Novak. “It’s

perhaps rooftop farms will become the norm and all people in urban areas will have access to fresh and affordable produce.

amazing how nature can be squeezed into New York City.”

rooftop resources

Living Roof Quick Facts Barrett Roofing Company

b

b

1 square meter of extensive living roof removes up to 0.2 kg of airbourne particulates per year.

b

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four square meters of extensive living roof on a home will supply enough ox ygen to fully support a family of four

b converting a tr aditional roof to a living roof on a home will allow it to absorb up to 95% of the r ain that falls on it compared to less than 1% on a conventional, non-living roof.

b living roofs provide homes for many birds that would be otherwise displaced in dense urban areas.

b living roofs are natur ally fire resistant. the plants and growing medium help quench flames.

hardiness zones for the continenetal united states

zone 3: -40 to -30˚ F zone 4: -30 to -20˚ F zone 5: -20 to -10˚ F zone 6: -10 to 0˚ F zone 7: 0 to 10˚ F zone 8: 10 to 20˚ F zone 9: 20 to 30˚ F

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zone 10: 20 to 30˚ F

Regional Plant Selection national gardening association Successful regional living roofs hinge on knowing what plants are suited for your zip code’s climate. What flourishes in Boston may wither in Fresno, California, or Cheyenne, Wyoming, since the cities don’t share identical growing conditions. Or the same plant could require different levels of care in different locations. To help us know what plants will thrive in our areas, the U.S. Department of Agriculture (usda) devised a cheat sheet, called the Hardiness Zone Map. Most plants you buy come with a reference tag that details optimal sunlight, season and watering schedule. Plants may also have a number listed beside a color-coded map of the United States. That number and map refer to hardiness zones.hardiness zone map ­T he usda’s map divides the United States into 11 hardiness zones. Hardiness zones, numbered one through 11, denote the lowest temperature ranges typical for that region and are ranked from coldest to warmest. Neighboring zones are 10 degrees higher or lower than each other. All zones, except for 1 and 11, also are split into “a” and “b” subregions, which are separated by 5 degrees. Why do hardiness zones only measure cold extremes?

Plants are more sensitive to cold than heat.

For example, peonies grow in hardiness zones 3 through 8, which means the flowers can withstand cold temperatures from 20 to minus 40 degrees Fahrenheit. You can feasibly plant them if you live in Austin, Texas, since your plant hardiness zone would be 8b. In normal weather, the mercury should drop no more than to 15 or 20 degrees Fahrenheit.

But you’d have to leave them behind if you moved to chilly Pinecreek, Minn. There, the hardiness zone is a 2b, and it could reach minus 45 to minus 40 degrees Fahrenheit.

When using the hardiness zones as your gardening guides, remember that it applies only to perennials. Annual plants die at the conclusion of their growing seasons, rendering the zone distinctions irrelevant. The usda hardiness zone map also isn’t flawless. Its accuracy varies depending on your location. If you live in the flatter geography of the Eastern and Plains states, the zones are fairly reliable. But as you travel west, the map skews somewhat because of the mountainous geography. Higher elevations and weather moving eastward from the Pacific Ocean interacts to produce isolated temperature in certain areas.

Suggested Living Roof Plants by Zone Plants are perhaps the most important part of a living roof. They provide both the aesthetic appeal and, through evapotransperation, help cool the roof and the air surrounding it.

They also provide habitat for local birds and insect. To get the most benefit from a living roof, it is vital to use plants that are native to your region and fit into your geographic climate zone. Though many plants are able to adapt to a rooftop climate, some are better suited than others. Some also have a longer growing period, resulting in longer green time.

This is just an overview of some of the most common rooftop plants that thrive in zones 4–6, the zones that cover the most area in the States. To learn more or learn about a specific plant, connect with your local living roof community or visit Emory Knoll Farms, one of North America’s most well-established living roof nurseries. www.greenroofplants.com.

Common Living Roof Plants

common Name: chives Botanical: Allium schoenopr asum Flower Color: Pink Winter Interest: No Height/spread: 15"/2"

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Chives are a very versatile plant. They can be used as both an ornamental and as a kitchen herb. The purple flower adds a bright pop of color. Chives are also self-sowing and easily spread over empty spaces.

common Name: Black Eyed Susan Botanical: Rudbekia Hirta Flower Color: Yellow Winter Interest: No Height/spread: 18”/9” Black Eyed Susan is hardy, drought resistant, and able to grow in almost every geographic region. When blooming in the summer, Black Eyed Susan brings bright yellow flowers to living roofs, attracting butterflies and birds.

common Name: Prickly Pear Cactus Botanical: Opuntia humifusa Flower Color: yellow Winter Interest: No Height/spread: 5”/8” Contraray to common thought, cactus can grow in many climate zones and is particularly well suited to the dry environment of a living roof. While the prickly pear will not grow to very large sizes on a living roof or flower as frequently, it will still retain a vibrant green color and thrive in the bright and hot sun that is a mainstay on many living roofs.

common Name: golden stonecrop Botanical: Sedum acre ‘Aureum’ Flower Color: yellow Winter Interest: yes Height/spread: 3”/10” Sedum Acre is a plant that loves the cooler weather. The foliage tends to stay bright green throughout the winter and most growth will occur in the cool early spring and late autumn months. This low growing ground cover will flower in light yellow in early summer.

common Name: common stonecrop Botanical: Sedum album Flower Color: white Winter Interest: No Height/spread: 4”/12”

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Sedum Album is a top choice for roof garden projects and living roofs. This bright green sedum sports panicles of white flowers. It spreads easily making it ideal for ground or roof cover. One caveat, Sedum Album doesn;t like being wet and requires excellent drainage.

common Name: african sunset Botanical: Sedum album ‘Mur ale’ Flower Color: white Winter Interest: yes Height/spread: 4”/12” A selection of Sedum Album, or Common Stonecrop, African Sunset has red foliage during periods of cold or stress. It adds valuable color during bleak winter months or during hot summer droughts. It is also very hardy, easliy tolerating both cold and hot temperatures.

common Name: rock pink Botanical: Talinum calycinum Flower Color: rose-pink Winter Interest: no Height/spread: 12”/7” An American native widely distributed through the mid-west, Rock Pink self sows freely, but doesn’t displace other ground covers but rather grows inbetween existing plants. The flowers are delicate and open every afternoon from May to September.

common Name: john creech t wo-row stonecrop Botanical: Sedum spurium ‘John Creech’ Flower Color: pink Winter Interest: no Height/spread: 4”/10” John Creech has rounded, flattened, medium green leaves, to 1 inch long, and star-shaped, pink flowers, to 3/4 inch wide, held in round corymbs, and borne in early summer. Sedums are excellent grown in rocky conditions on well-drained roofs.

common Name: roseum t wo-row stonecrop Botanical: Sedum spurium ‘Roseum’ Flower Color: pink Winter Interest: no Height/spread: 6”/8”

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Roseum Stonecrop has rounded, flattened, leaves, to 1 inch long, and star-shaped, rosy-red flowers, borne in mid summer. This is a vigorous, evergreen perennial with a mat-forming growth habit. Roseum Stonecrop is very hardy and drought tolerant.

common Name: pr airie dropseed Botanical: Sporobolus heterolepsus Flower Color: pale pink Winter Interest: no Height/spread: 24”/12” One of the most popular native grasses of all time, Prairie Dropseed creates height and a new form on a rooftop garden. The long and delicate leaved and the pink fragrant flowers brighten rooftop spaces. The flowers are also excellent for creating dried arrangements.

common Name: blue sedge Botanical: carex flacca Flower Color: blue-gr ay Winter Interest: yes Height/spread: 16”/12” This tough sedge, or grass, can grow in very diverse habitats. It is often found in full sun with prairie grasses but will do well in the shade of large trees or buildings. It retains its green color year round, making it great for roofs in winter.

common Name: autumn moor gr ass Botanical: sesleria autumnalis Flower Color: light green Winter Interest: yes Height/spread: 8”/14” This cool-season grass begins the season with bright green blades. In late summer and early fall, it produces silvery inflorescences which complement its golden-hued autumn foliage and persist throughout the winter. It is a great option for rooftops in winter.

common Name: t wo-row stonecrop Botanical: Sedum spurium ‘Fuldaglut‘ Flower Color: pink Winter Interest: yes Height/spread: 6”/8”

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Two-Row Stonecrop is one of the red foliage Sedum Spuriums. It is very easy to grow, covers the ground quickly, and requires very little water to thrive. Forming a dense mat of leaves, it produces red flowers in late July or August and keeps its color through winter.

common Name: spruced leaved sedum Botanical: Sedum reflexum Flower Color: yellow Winter Interest: no Height/spread: 4”/8” Spruced Leaved Sedum looks like a bit like a Blue Spruce tree, only it is much softer in texture. It gives a nice touch of blue/grey on the roof and when planted around more vibrant sedums, prvices a nice contrast. It blooms in early summer and attracts butterflies.

common Name: bailey’s gold stonecrop Botanical: Sedum floriferum ‘Weihenstephaner Gold’ Flower Color: yellow Winter Interest: yes Height/spread: 4”/10” A favorite among the groundcover sedums, Bailey’s Gold is covered in canary yellow starshaped flowers in late spring. Tough and easy to grow, it survives in just about any sunny location and spreads slowly to form a lustrous green groundcover.

common Name: tasteless stonecrop Botanical: Sedum sexangulare Flower Color: yellow Winter Interest: yes Height/spread: 4”/8” A quick-spreading groundcover with jellybean foliage that turns shades of rose and copper in the sun creating a tapestry of color that bursts in to brilliant yellow bloom in mid summer.

Often used on green roofs, it thrives in any sunny location. Tough and easy to grow.

common Name: dr agon’s blood Botanical: Sedum spurium ‘White Form’ Flower Color: white Winter Interest: no Height/spread: 6”/8”

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A white flowering form of Sedum spurium also known as Sedum spurium alba superbum.

Dragon Blood Sedum works well in cooler climates and it can shrug off heavy snow cover, heavy rains, cold winters, and hot summers. It is very versatile.

common Name: hardy ice plant Botanical: Delosperma nubigenum ‘Basutoland’ Flower Color: Yellow Winter Interest: No Height/spread: 3”/10” Delospermas are low-growing plants with thick leaves. The hardiest of the Delospermas, this plant is notable for its ability to absorb a rainwater after a dry period. Hardy Ice Plant has fleshy leaves and brilliant yellow flowers in early summer.

common Name: or ange stonecrop Botanical: Sedum kamtschaticum Flower Color: yellow Winter Interest: no Height/spread: 6”/10” Stonecrop is also known as a sedum. The Orange Stonecrop is a somewhat taller sedum. It is remarkably tough and drought tolerant plant for its size and is well-suited to a rooftop environment. The bright colors attract bees, butterflies, and birds.

Regional Living Roof Organizations This is by no means an exhaustive list. Rather these are people and organizations that I have been in contact with and found to be very helpful and passionate in passing along their living roof knowledge, plant information, and striking visual imagery.

northeast DC Greenworks DC Greenworks, is the national capital region’s preeminent green roof advocate and educator, as well as a one stop shop for green roof consultation, design, and installation. Serving the Washington, D.C. community by providing training, tools, and techniques that utilize, protect and advance the environment, DC Greenworks sees a vital connection between economy and ecology, employment potential and environmental sustainability. DC Greenworks actively seek to discover, promote, and deliver cutting edge solutions that are cost effective. web: www.dcgreenworks.org

Capital Green Roofs Capitol Greenroofs has been founded to provide design and construction administration services to ensure that home owners, developers, public planners, facility managers and architects understand how these systems are installed and maintained. The living roof and landscape architecture group based in Washington, d.c. Includes a networking blog of over 1,000 living roof professionals from across the country who are open to answering questions, offering advice, and sharing stories and pictures of their living roof experience. web: www.capitolgreenroofs.com

Emory Knoll Farms Located in Maryland, Emory Knoll Farms is a leading supplier of plants and plant expertise for extensive green roof systems. They offer a high level of service in selecting the optimal plants for each installation. They currently stock over 100 varieties of green roof plants and are always acquiring and testing new plants. In addition they have r&d plots on site to test plants, and work with universities, supporting various green roof research projects. Their plant database covers all geographic zones and owners Ed and Lucie Snodgrass have written Green Roof Plants, the go-to book for living roof plants.

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web: www.capitolgreenroofs.com

southeast Earth To Sky Roofing Earth to Sky Roofing is dedicated to quality installation of each living roof. Owner Janie Turnamian is an Accredited Green Roof ProfessionalSpecialist that oversees all installations. She is also a green roof consultant dedicated to educating people about living roofs and can help plan, design, organize, install, maintain and guarantee living roofs will stay healthy. web: www.earthtoskyroofing.com

midwest Minnesota Green Roofs Council The Minnesota Green Roofs Council promotes green rooftop technology as a sustainable building strategy in Minnesota and the Midwest. They work to educate developers, architects, landscape architects, engineers, roofers, building owners, policy makers and others about green rooftops as a cost-effective strategy to improve building performance, reduce environmental impacts and improve urban livability. The steering committee meets monthly and hosts workshops, social events, tours of local green rooftops. They have developed resources like the RoofBloom guide and Minnesota Green Roofs Directory. web: www.mngreenroofs.org

Urban Habitat Chicago Urban Habitat Chicago (uhc) formed in 2004 to demonstrate the viability of sustainable concepts and practices in urban environments through research, education, and handson projects. Working at the intersections of urban agriculture, the built environment, materials recovery and reuse, and emerging local industries—focusing on creating seamless transitions in the cycles of resources at all scales, uhc has pioneered methods of rooftop urban agriculture that yield an abundant harvest of food in a very small amount of rooftop growing medium. web: www.urbanhabitatchicago.org

Intrinsic Perennials Intrinsic Perennial Gardens Inc. started in 1992. Currently they list over 900 varieties of plants and have a special focus on living roof plants. They are a wholesale nursery, propagate about 80% of the plants grown, and have a robust educational initiative, focusing on plants native to the Midwest. web: www.intrinsicperennialgardens.com

northwest Hadj Design Hadj Design, a living roof design studio in northern Washington, is dedicated to both living roof installation and education. Founded by Patrick Carey, an offical instructor for Green Roofs for Healthy Cities, an organization dedicated to the advancement of green roofing awareness and infrastructure in North America, Hadj Design offers a variety of workshops to help increase green roofing awareness and disseminate practical knowledge. The workshop strategy is an integral part of the business plan. Workshops provide some of the best public information available on living roofs.

Workshops also provide technical expertise priced for even the smallest of green roof projects. web: www.hadj.net

Portland Bureau of Environmental Services The Portland Bureau of Envrionmental Services (pbes) includes the Portland Ecoroof Program, a public outreach education program promoting living roof incentives, how-to workshops, and sustainable building events. A clearinghouse for all living roof information, the pbes’s mission is to empower all Portlanders to embrace sustainable design for their own benefit and the benefit of the greater city of Portland. web: www.portlandonline.com

southwest Ladybird Johnson Wildflower Center The mission of the Lady Bird Johnson Wildflower Center is to increase the sustainable use and conservation of native wildflowers, plants, and landscapes. Now an organized Research Unit of the University of Texas at Austin, the extensive living roof at the center is a valuable research tool to study living roof performance in hot and arid landscape. They also offer many public education classes promoting the preservation of native plants. web: www. wildflower.org

canada Green Roofs for Healthy Cities Green Roofs for Healthy Cities’ stated mission is to increase the awareness of the economic, social, and environmental benefits of green roof infrastructure across North America and rapidly advance the development of the market for green roof products and services. Although the current roof market does not value many of the tangible public and private benefits of green roofs to their full potential, Green Roofs for Healthy Cities are striving to facilitate changes that will bring green roof technologies to the forefront of high performance green building design. They offer professional education, sponsor several international conferences, and keep a database of living roofs worldwide.

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web: www.greenroofs.org

australia Green Roofs Australia Green Roofs Australia (gra) is a not-for-profit public membership organisation with an elected committee that draws together the various governmental, organisational and business groups and individuals interested in being kept informed about green roof science, technology, practice, regulations and specifications. An active part of the world-wide living roof movement, gra promotes green roofs as an effective response to climate change and city heat island effects, and to reduce buildings’ carbon footprints. They offer public education as well as sponsor living roof tours to help demystify the living roof movement. web: greenroofs.wordpress.com

United Kingdom Livingroofs.org Livingroofs.org is an independent organization that promotes living roofs in the UK and is the representing UK member of the European Federation of Green Roof Associations.

Livingroofs.org has been actively promoting living roofs to such an extent that London now has a distinct living roof policy and other cities and areas in the UK are developing similar approaches to encourage the uptake of living roofs. The website highlights the latest research information on the benefits of living roofs and provides case studies of seminal living roof projects throughout the UK. The site also provides details of contractors, manufacturers, suppliers and designers who are active in the European living roof industry. web: www.livingroofs.org

About the Contributors Cathy Erway Cathy Erway is a freelance writer based in Brooklyn. She is the author of the book, The Art of Eating In: How I Learned to Stop Spending and Love the Stove, based on a twoyear mission to forgo restaurant or take-out food and writes the blog, Not Eating Out in New York. She writes about small farms for Saveur.com, green living tips for The Huffington Post, and her work has appeared in Edible Brooklyn and The L Magazine.

She also hosts the weekly talk radio show, Cheap Date, on Heritage Radio Network, tackling all topics food and love-related.

william McDonough William McDonough is a world-renowned architect and designer, and winner of three U.S. presidential awards. He is founder and principal of William McDonough+Partners, Architecture and Community Design; and McDonough Braungart Design Chemistry; and a venture partner at VantagePoint Venture Partners. McDonough co-authored with Dr. Michael Braungart, The Hannover Principles: Design for Sustainability (City of Hannover, 2000), and Cradle to Cradle: Remaking the Way We Make Things (North Point Press, 2002).

Dr. Bas Baskaran Dr. Baskaran is a Group Leader and Senior Research Officer at the nrcc, Institute for Research in Construction (nrc/irc). He has spent 25 years researching wind effects on building envelopes through wind tunnel experiments and computer modeling.Baskaran acts as adjunct professor at the University of Ottawa. His work in has received national and international recognition.He has an extensive research record with more than 150 publications in refereed journals and conference proceedings. He has received several honors and awards. A professional engineer, Baskaran received his master’s degree in engineering and a doctorate from Concordia University, Montreal, Canada. His research topics focused on the wind effects on buildings and earned best dissertation

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awards from the Canadian Society of Civil engineers.

Patrick Carey Carey’s academic background is in architecture and philosophy. While directed the Northwest EcoBuilding Guild’s Green Roof project from 2000–2004, Carey designed and installed 20 residential green roofs. In 2003, he was asked to help develop the training content for Green Roofs for Healthy Cities’ training program for architects, landscape architects, and building professionals. Carey then became one of their first trainers for North America. Carey’s firm, Hadj Design, has completed another 65 commercial and residential green roofs. He remains dedicated to promoting residential green roofs and educating green roof professionals. Carey also is the architecture editor for Greenroofs.com.

Thanks This project would not be possible without a lot of help from the sustainable design community. Many thanks to the sustainable design and living roof community both in the States and worldwide for education, information, and never discouraging my many silly questions. Your passion for living roofs and hope for the future of urban America has inspired me and I feel truly blessed to be a part of the living roof movement.

Thanks also to the professors at the Academy of Art University especially Carolina DeBartolo, Marc English, Jeremy Stout, and Anitra Notthingham, and Aran Baker for helping me on my thesis journey and being committed to the next season of work. And last a huge thanks to my family and the people of Steamboat Springs, Colorado who first showed me how dazzling nature can be and got this whole idea started.

Image Credits patrick boury

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sage brown

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Casey Cunningham

44 / 53 / 54 / 61

grant davis

68 / 84

Sheryl daye

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marcus de la fleur lisa hammershaimb

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16 / 18 / 26 / 31 / 32 / 33 / 36 / 43 / 47 / 50 / 58 / 65 / 79 / 80 / 87 / 94

bruce hemstock 38 Susanne Jespersen

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london permaculture society

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David Plechner

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regeneration group

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dustin sacks 20 ed snodgrass

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janie turnamian 62 mitch waxman 70

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edgar zuniga, jr 64

Bibliography bill mcDonough, “buildings like trees, cities like forests.” the catalogue of the future. new Jersey: Pearson, 2002.

Matt Burlin, et al. Ecoroof Handbook 2009. oregon: City of portland, 2009.

Bas Baskaran, Living ROof Performance Study: Thermal performance of green roofs through field evaluation. National Research Council of Cananda, 2003.

Lisa Cunningham, “view from the bridge.” Metropolis Magazine.

September 2005.

Patrick Carey, (2004) The residential front: residential green roof policy, strategy, and tactics. Unpublished paper presented at green roofs for sustainable communities, Seattle, WA. Cathy Erway. “A rooftop Farm for the future.” no eating out in nyc.

May 27 2009. Web. November 12 2009.

Barret Roofing, “Roofscape facts and ecological benefits.” Barrett Roofs. November 9 2009. web. November 24 2009.

colophon This book was designed by Lisa Hammershaimb using the two typefaces, Klavika and Maxime. All headings, tables, and captions are set in Klavika. Klavika was designed in 2004 by Eric Olson, a type designer and teacher based in Minneapolis, Minnesota.

All body text is set in Maxime. Maxime was designed in 1999 by Éric de Berranger, a type designer based just outside of Paris, France. When working together Klavika and Maxime produce a dynamic reading experience that embraces both the clean modern lines of a sans serif face with the classic elegance of a serif.