A New Report Finds Sustainable Roofs Deliver Millions in Benefits to ‘Roof Aware’ Cities

“Roof Awareness” has come a long way during the years. It used to be that people only thought about their roofs when something went wrong. Building owners then started realizing that making smart choices about the roof could save money on energy costs. Roofs are now seen as essential platforms for cities to meet energy-efficiency and renewable-energy goals, to improve the health and quality of residents’ lives, and to achieve social equity. A new effort to better quantify those benefits and costs shows cities with good roof awareness are reaping millions in economic benefits.

TABLE 1: Summary of cost-benefit analysis results (NOTE: There is no internal rate of return, simply payback, or benefit-to-cost ratio for rooftop PV because we all rooftop PV systems are financed with a PPA [so there is no upfront cost to DGS]).

TABLE 1: Summary of cost-benefit analysis results (NOTE: There is no internal rate of return, simply payback, or benefit-to-cost ratio for rooftop PV because we all rooftop PV systems are financed with a PPA [so there is no upfront cost to DGS]).

With that change in role comes new challenges for evaluating what type of roof makes sense for building owners and cities alike. There are well-developed building models and field studies that give us great insight into how sustainable roofing—that is, reflective, vegetated or solar roofs—saves energy and energy costs. But there is not a single tool that could evaluate all the benefits that accrue from good roofing choices beyond energy savings, such as better health, enhanced air quality, greater stormwater management and improved social conditions. Until now, that is.

A recently released report—the “Affordable Housing Smart Roof Report”—from Washington, D.C.-based Capital E, a firm dedicated to accelerating the transition to a low-carbon economy, now allows city officials and owners of affordable housing developments to see and calculate the full lifetime costs and benefits of roof decisions. “This is the first model that helps the user puta dollar value on the various benefits of sustainable roofing options. We see this as a great tool for contractors looking to quantify the full benefits of sustainable roofing for their potential clients. It will also help city officials to enact policies that recognize the value of smarter roofing that may not be directly visible on the building owner’s books,” says Keith Glassbrook, a Capital E senior analyst and one of the lead developers of the new model.

TABLE 2: Present value summary of costs and benefits for the three technologies on all low-slope DGS roofs (NOTE: All PV is financed with a PPA so there is no upfront cost to DGS; results may not sum due to rounding).

TABLE 2: Present value summary of costs and benefits for the three technologies on all low-slope DGS roofs (NOTE: All PV is financed with a PPA so there is no upfront cost to DGS; results may not sum due to rounding).

Building the Tool

Rather than reinventing the wheel, Capital E identified existing tools, models and methods from the huge base of existing science for each item in its cost-benefit analysis. The model integrates these individual, detailed components into a form that is accessible and easy to use for non-scientists and that provides straightforward results in dollars per square foot.

The model is an extension of an analysis undertaken for the Washington, D.C., Department of General Services (DGS) as part of its Smart Roofs Initiative. The initiative is designed to help Washington achieve its aspirations to become the greenest, healthiest, most equitable city in the U.S. by using the roofs of city-owned buildings more thoughtfully. DGS owns and controls more than 400 buildings in Washington, including office buildings, schools and hospitals. The city is using this portfolio (28 million square feet of buildings with approximately $62 million in annual energy expenditures) to drive deep improvements in energy efficiency and achieve other objectives.

Like a growing number of cities, Washington, D.C., is committed to using its roofs to deploy photovoltaic panels to generate electricity, cool roofs to reflect sunlight and reduce unwanted heat gain in summer, and green roofs to cut stormwater runoff that results in water pollution and requires construction of expensive water-treatment plants and other grey infrastructure. Tommy Wells, a former councilmember and current director of the District Department of the Environment, summarized the reasons in the Smart Roof cost-benefit report’s press release: “Past research shows that ‘smart’ roof strategies that reduce extreme temperatures in buildings can literally save lives. This new report provides additional justification for cool, green, and solar roofing solutions by showing that they also make compelling financial sense as we work to make D.C. a healthier and more sustainable city.”

Washington has been among the most advanced cities in the nation in deploying sustainable roof technologies. But because there was no established methodology for quantifying the full cost and benefits—including health benefits—for any of these technologies, Washington to date had not been able to quantify the full costs and benefits of these roof choices or compare the merits of each to make informed decisions about which technologies to deploy and at what scale. The analysis undertaken by Capital E to remedy this issue concluded that DGS’ Smart Roofs program can deliver between $47 and $335 million in benefits to the city over 40 years, depending on the roof technology chosen.

More Analysis

A parallel analysis was funded by the New York-based JPB Foundation, which seeks to enhance the quality of life in the U.S. by creating opportunities for those in poverty, promoting pioneering medical research, and enriching and sustaining the environment. JPB Foundation launched its analysis based on the success of this initial analysis by DGS. This time, the model was adapted to evaluate actual affordable-housing buildings in Baltimore; Los Angeles; Philadelphia; and Washington, D.C. The sample buildings, which were part of the National Housing Trust, Washington, or Columbia, Md.-based Enterprise Community Partners Inc.’s portfolios, included steep- and low-slope roofs, high- and low-rise structures, as well as some attached row houses. The project team for this study included the National Housing Trust; Washington-based American Institute of Architects; Washington-based Global Cool Cities Alliance; Enterprise Community Partners; and U.S. Green Building Council, Washington. In each city and building type evaluated, the model found sustainable roofs would generate more benefits than they cost (first cost and maintenance) and would, in some cases, have an immediate payback.

The results were variable by building and city but they confirmed that sustainable roofing was the superior economic choice compared to traditional dark roofs in the cities studied.

The JPB Foundation analysis shows there is no one-size-fits-all solution to maximize value with sustainable roofing. For example, green roofs made the most sense in Washington, D.C., because of the city’s stormwater rules. On the building in Baltimore, cool roofs were the best choice. The results were variable by building and city but they confirmed that sustainable roofing was the superior economic choice compared to traditional dark roofs in the cities studied.

A second phase is currently underway by JPB Foundation to extend the model to large areas of cities to capture the impact of sustainable roofs at a community scale, as well as other technologies, such as reflective pavements, and to better quantify some of the social benefits of cooler, more enjoyable surroundings.

Green Roof Provides Learning Opportunities at the University of Iowa’s Pappajohn Biomedical Discovery Building

Established just 59 days after Iowa became a state in 1847, the University of Iowa, Iowa City, boasts a number of firsts. In 1855, it became the first U.S. public university to admit men and women; at that time, its enrollment consisted of 124 students—41 of which were women. In 1873, it was the first school to grant a law degree to a woman. In 1895, it became the first university to place an African American on a varsity sports team.

As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC

The university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC


In more recent years, the university has strived to lead via its environmental efforts. As a Green Power Partner of the Washington, D.C.-based U.S. Environmental Protection Agency, the university pledges to reduce the environmental impact of electricity generation through the use of renewables. In 2010, it established its first sustainability plan—2020 Vision UIowa Sustainability Targets, which contains the following goals:

  • Become a Net-negative Energy Consumer
  • Green Our Energy Portfolio
  • Decrease Our Production of Waste
  • Reduce the Carbon Impact of Transportation
  • Increase Student Opportunities to Learn and Practice Principles of Sustainability
  • Support and Grow Interdisciplinary Research in Sustainability-focused and Related Areas
  • Develop Partnerships and Advance Collaborative Initiatives, both Academic and Operational

Among the University of Iowa’s strategies to achieve its sustainability goals is ensuring all new construction and major renovations on campus achieve a minimum LEED Silver certification from the U.S. Green Building Council, Washington.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes. PHOTO: Scott Nagel


As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes, including glow-emitting sealants, paints, carpet and other materials; water-efficient landscaping; and recycled content and regional materials. It also achieves an-other university first: three green roofs, one of which provides students the opportunity to grow medicinal plants.

Opting for Trays

Des Moines, Iowa-based landscape architecture firm Confluence has been completing projects at the University of Iowa for many years through its Iowa offices—Des Moines and Cedar Rapids. Confluence was hired by the project’s architect of record, Rohrbach Associates PC Architects, Iowa City, to complete landscaping around and on top of the Pappajohn Biomedical Discovery Building in the form of three green roofs that total approximately 6,440 square feet. Despite the building’s consider-able roof area, the design team opted to install the green roofs on lower roof areas upon which building occupants would be looking. The rest of the roof cover is a reflective membrane system.

Confluence provided the layout for a modular green roof on the three distinctive roof areas. Patrick Alvord, PLA, RA, LEED AP, a principal in Confluence’s Cedar Rapids office, notes the chosen tray system was off-the-rack, which is what made it appealing to him and his colleagues. “We spent a lot of time talking to the manufacturer and they were just great to work with,” Alvord says. “We had a number of case studies of work they had done in the Chicagoland area that had proven very successful, so we had a very high level of comfort right out of the gate.”

Alvord opted to use the 6-inch-deep tray model because it would provide some flexibility in the plant materials that could be specified. “We were able to specify different plant materials in the plan of the roof to coordinate with shade, densities and location,” he says. “In areas where the roof would be highly visible from floors above, we did some patterning with the plants. In areas where we had the opportunity to go deep, we planted deeper-rooting plants that will grow taller and provide a denser plant palette.”

The plants are a mix of native and adaptive Iowa plants, as well as recommendations from the green-roof supplier. “It’s a mix of perennials, grasses and forbs, ranging from sedums to liatris to a number of different things,” Alvord notes.

Pages: 1 2

Fewer Limitations for Green Roofs

The limits of green-roof feasibility are being redefined by ZinCo’s Summer Plains system combined with Aquatec.

The limits of green-roof feasibility are being redefined by ZinCo’s Summer Plains system combined with Aquatec.


The limits of green-roof feasibility are being redefined by ZinCo’s Summer Plains system combined with Aquatec. An extensive or intensive green roof can be created on a flat, sloped or even an inverted roof, depending on the selected substrate depth and the suitability of the plants for the given location. The first layer is a protective layer on the root-resistant waterproofing membrane. This is followed by the Aquatec AT 45 water distribution, storage and drainage elements in conjunction with the DV 40 wicking mat. Water is drawn upward through the wicking mat and made available to the substrate directly in the root area. The system is intended for all green roofs that require an additional irrigation system and will provide particular cost savings in arid regions where irrigation is required.

Projects: Office

DPR Construction, Phoenix

Eighty-two Daylighting Systems were installed in the renovated 16,533-square-foot building.

Eighty-two Daylighting Systems were installed in the renovated 16,533-square-foot building.

Team

Roofing contractor: Arithane Foam, Corona, Calif.
Architect/engineer: SmithGroupJJR, Phoenix
Daylighting systems distributor: Norcon Industries, Guadalupe, Ariz.

Roof Materials

Eighty-two Daylighting Systems were installed in the renovated 16,533-square-foot building, formerly an abandoned retail boutique at the corner of 44th Street and Van Buren in Phoenix.

“The use of the Daylighting Systems was an integral part of our sustainability and lighting energy savings plans for the renovated space,” says Dave Elrod, regional manager of DPR Construction, Phoenix. “The products are a cost-efficient solution to provide lighting since they nearly eliminate the need for artificial daytime lighting.”

In addition, the roof is composed of foam with an R-25 insulation value (approximately 4-inches thick) over plywood sheathing.

Daylighting systems manufacturer: Solatube International Inc.
Foam roofing manufacturer: Quik-Shield from SWD Urethane

Roof Report

DPR Construction is a national technical builder specializing in highly complex and sustainable projects. In less than 10 months, the design-build team researched, designed, permit-ted, and built a highly efficient and modern workplace with numerous innovative sustainability features.

In addition to natural daylighting, the office features an 87-foot zinc-clad solar chimney, which releases hot air from the building while drawing cooler air in; shower towers that act as evaporative coolers to regulate building temperatures; 87 operable windows designed to open and close automatically (based on indoor/outdoor temperatures); and two “vampire” shut-off switches to keep electrical devices (radios, cell-phone chargers, microwaves) from using plug energy when no one is in the office.

Access to the building was limited during construction. Spray foam roofing, which took about seven days to complete, had to be done in small quadrants because of the tight schedule as work was progressing in the other sections. The roofing workers were challenged by the barrel-shaped roof, which created footing difficulties, and the many penetrations that had to be flashed, including all PV support legs, Solatubes, skylights and HVAC penetrations. Work was completed in the middle of winter, so additional protections and efficiencies were required.

The circa-1972 building has been officially certified as a Net-Zero Energy Building by the Seattle-based International Living Future Institute through its Living Building Challenge program. It also has received LEED-NC Platinum certification from the U.S. Green Building Council, Washington, D.C.

PHOTOS: Ted Van Der Linden, DPR Construction

Pages: 1 2 3 4 5 6

Kill Moss and Algae in an Environmentally Friendly Manner

Moss Melt Concentrate, a moss and algae herbicide from Green Spear Inc., has recently received EPA registration for use on roofs, lawns, turf, and outdoor surfaces and structures.

Moss Melt Concentrate, a moss and algae herbicide from Green Spear Inc., has recently received EPA registration for use on roofs, lawns, turf, and outdoor surfaces and structures.

Moss Melt Concentrate, a moss and algae herbicide from Green Spear Inc., has recently received EPA registration for use on roofs, lawns, turf, and outdoor surfaces and structures. The active ingredient is an emulsified d-Limonene, which acts as a natural degreaser. It strips away the waxy surface of moss and algae without direct sunlight or warm temperatures. The product is rain-fast within one hour. Moss Melt will not stain concrete, brick, pavement, stucco or wood and will not damage gutters, metal flashing or downspouts. One gallon kills up to a 12,500-square-foot area. The product currently is available in the Pacific Northwest.

Planning Guide Explores Economics, Green Attributes and More of a Green Roof System

American Hydrotech's Garden Roof Planning Guide

American Hydrotech’s Garden Roof Planning Guide

The Garden Roof Planning Guide from American Hydrotech will lead you from conception to completion of your garden roof. Explore the economics, environmental qualities, stormwater management and green-building attributes of a Garden Roof Assembly. You’ll learn about the many options of Garden Roof Assemblies and their components, design considerations, growing media and vegetation, and installation and maintenance. The digital brochure features tap-to-zoom product photography, video animations, real-world applications, plant-selection guides, and interactive opportunities to learn more about the Garden Roof Assembly and other products from American Hydrotech. The Garden Roof Planning Guide is available for free download in the iTunes store.

A Green Roof Provides Residents of a Senior Housing Complex with an Improved View

The Findlay Teller Apartments provides affordable housing for low-income seniors in the Bronx, N.Y. The complex includes 32 one-bedroom and 131 efficiency units. Its 9,925-square-foot green roof is its most prominent green-building element and gives residents a welcomed view of green space.

Built in 1906, the dilapidated building was revitalized by three local Bronx organizations.

Built in 1906, the dilapidated building was revitalized by three local Bronx organizations.

“Many green roofs are on top of buildings where no one can see and enjoy them. The Findlay Teller green roof, particularly the sections installed on the terrace level and second-floor roofs, has many windows that look out on the [green roof sections],” says Antonio Freda, owner of Bronx-based Freda Design Associates Ltd., the architect for the apartment building’s renovation. “In fact, 90 percent of the apartments have a view of the green roof.”

RESTORING A NEIGHBORHOOD LANDMARK

Located at 1201 Findlay Avenue in the Morrisania neighborhood of the Bronx, the community landmark has a long history. The building was constructed in 1906. The Daughters of Jacob, a non-profit service organization, originally used the building as a hospital and nursery facility. It was renovated in 1920. The east and west wings were added in 1952.

Converted to subsidized senior housing under the U.S. Department of Housing and Urban Development (HUD) Section 202 program in 1978, and known as Findlay Plaza, the building deteriorated over the years. By December 2007, the apartments had a lowly score of 34 out of 100 on HUD’s Housing Quality Standards. Buildings must score at least 86 for their conditions to be rated healthy and safe. Eventually, HUD foreclosed on the property.

In 2009, three local organizations, the Citizens Housing and Planning Council, the Local Initiatives Support Corp. and the Belmont-Arthur Avenue Local Development Corp. (BAALDC), worked together to win the support of the building’s tenants and neighborhood leaders to acquire and rehabilitate the property.

Roofing workers spread the growing media on the roof.

Roofing workers spread the growing media on the roof.

BAALDC, which strives to prevent the deterioration, blight and abandonment of at-risk housing in the Bronx, established the Findlay Teller Housing Development Fund Corp. (Findlay Teller HDFC) to take on the challenge of assembling financing and renovating the building.

“The building was in a very sad state of disrepair,” notes Joe Cicciu, executive director of BAALDC and president of Findlay Teller HDFC. “We put together $20 million in funds from many different sources, including a major grant from JPMorgan Chase, to save and rehabilitate the building.”

GREEN BUILDING AND A GREEN ROOF

Notias Construction Inc., Flushing, N.Y., was the general contractor for the project. The firm managed the renovation according to Enterprise Green Communities Criteria, a program of Columbia, Md.-based Enterprise Community Partners, a non-profit dedicated to creating opportunity for low- and moderate-income people through affordable housing in diverse, thriving communities. Required by the New York City Department of Housing Preservation and Development, the criteria define standards for green-building practices applicable to affordable housing. Thus, the renovation included a new structural roof with two layers of insulation, high-efficiency boilers, replacement windows and new energy-efficient lighting. In addition to the green roof, permeable pavement in the parking area reduces stormwater runoff.

PHOTOS: XERO FLOR AMERICA

Pages: 1 2

A Minneapolis Neighborhood Plans to Bring Solar, Vegetation and Bees to its Rooftops

As part of its commitment to maintain and enhance the physical, social and economic environment of its Minneapolis neighborhood, the Southeast Como Improvement Association (SECIA) has begun a program in which it is matching the owners of buildings with low-slope roofs to solar and green roof providers, as well as beekeepers.

The Southeast Como neighborhood is surrounded by industrial buildings and essentially is the last of Minneapolis’ industrial hub. A community resident who considered the industrial buildings’ rooftops wasted but valuable space approached SECIA about partnering with Minnesota Community Solar. The for-profit organization builds large solar arrays in locations ideal for generating solar power—like roofs—and works with utilities so any Minnesota ratepayer can have access to solar energy. While SECIA’s Executive Director Ricardo McCurley was researching that option, he met a green-roof consultant who is part of the Minnesota Green Roofs Council, a nonprofit that supports green roofs in the state. In addition, Minneapolis recently eliminated permit requirements to maintain beehives in the city above 1 story.

“It occurred to me we should just play matchmaker,” McCurley says. “Let’s get a bunch of options on the table and match them to local property owners.”

After receiving a $3,000 grant from Minnesota’s Clean Energy Resource Teams, an organization that connects individuals and their communities to resources that will help them implement community-based clean-energy projects, SECIA began surveying the neighborhood. “We have an intern who currently is looking at aerial images of roofs and doing rough estimates of square footage, as well as collecting contact information for building owners,” McCurley notes. “Then we’ll be contacting all these property owners in person and via telephone and asking them questions about their flat roofs, like ‘Are you planning to reroof any time soon? How is the stormwater management on your property?’”

If the property owners show interest in learning more about sustainable options for their rooftops, SECIA will invite them to a luncheon that McCurley compares to speed dating. “We’ll have different providers of the various technologies at the luncheon, so they can talk about options,” he says. “Then if we make a match, we’re going to help the property owner through the process of finding grants to make it more affordable for them.”

McCurley thinks the program will be a success if just one property owner opts to install solar panels, a green roof or beehives. But he hopes for many installations and to make more connections within the neighborhood to expand how roofs are used. “We’re big into urban agriculture in the neighborhood,” McCurley explains. “Wouldn’t it be cool if one of the green roofs connects with a farmer who would lease the green-roof space?”

Although the program currently is in its infancy, McCurley is certain it will increase Southeast Como residents’ awareness about the benefits of green roofs, solar arrays, bees and even trees. “We’re dealing with the emerald ash borer here in the Twin Cities, particularly in our neighborhood. We’re already losing a lot of our tree canopy,” he says. “If our residents’ buildings were shaded by a beautiful ash tree and now they’re not, they’re going to feel that in HVAC costs. So what are the options to make a building more efficient? This program provides many great options!”

Want to Be Involved?
If you’d like to assist in the Southeast Como Improvement Association’s mission to bring solar, vegetation and bees to its rooftops, email Rooftops@comogreenvillage.info, SEComo@secomo.org or call (612) 676-1731.

Project Profiles: Health Care

MASSACHUSETTS GENERAL HOSPITAL, BOSTON

TEAM

Roofing contractor: Chapman Waterproofing Co., Boston
Architect/engineer: Cambridge Seven Associates Inc., Cambridge, Mass.
Membrane and waterproofing manufacturer: Kemper System America Inc.

Massachusetts General Hospital, Boston, features a Kemperol waterproofing and roofing membrane for its green roof.

Massachusetts General Hospital, Boston, features a Kemperol waterproofing and roofing membrane for its green roof.

ROOF MATERIALS

The Kempertec EP-Primer was used to prepare the substrate surfaces for membrane installation and served as a temporary waterproofing system, allowing the project to be exposed to the harsh New England winter while it was completed in phased stages.

The owners chose the Kemperol waterproofing and roofing membrane, a two-component with catalyst, high-performance, seamless and self-terminating cold-fluid-applied reinforced unsaturated polyester system. The monolithic edge-to-edge rot- and root-resistant Kemper membrane is engineered to resist degradation from UV exposure and heat intensity and is resistant to most common chemicals.

ROOF REPORT

Founded in 1811, Massachusetts General Hospital is the third oldest general hospital in the U.S. and the oldest and largest in New England. The 900-bed medical center offers sophisticated diagnostic and therapeutic care in virtually every specialty and subspecialty of medicine and surgery. When MGH’s owners envisioned constructing a new 9,000-square-foot green roof above the MGH cancer wing, they had two chief concerns: safety and long-term durability.

The landscaped roof design includes four different gardens with extensive shrubbery, trees and grass designed to provide cancer patients with a haven for relaxation and meditation to aid in the healing process.

A key challenge concerning the hospital’s green roof was its hundreds of penetrations, spaced inches apart, for a sprinkler system to irrigate the landscaped roof. A leak-detection system was installed across the entire square footage of the project to detect water before it seeps into the interior of the building. The leak-detection system confirms the project’s seal-tight success. Upon completion, Kemper System provided a 20-year, no-dollar-limit warranty.

PHOTO: KEMPER SYSTEM AMERICA INC.

Pages: 1 2

Green Roof Is Synthetic

EasyTurf's green-roof-surfacing-system

EasyTurf’s green-roof-surfacing-system

EasyTurf has debuted its green-roof-surfacing-system, which is a realistic, low-weight and cost-saving landscape. The artificial grass system meets requirements of a green roof project, such as preserving, enhancing and making viable living space from areas that were traditionally wasted. EasyTurf’s synthetic grasses are engineered specifically for military surfaces, commercial and residential athletic and playground surfaces, putting greens and pet-friendly landscapes.

(866) 327-9887