New NHL Practice Facility and Community Center Sports Vegetative Roof

The American Hydrotech Extensive Garden Roof Assembly was installed on two sections of the roof. The system was topped with pre-grown mats featuring mature sedum plants. Photo: American Hydrotech Inc.

The Chicago Blackhawks have captured the hearts of the city of Chicago along with three Stanley Cups in the last decade. The Blackhawks routinely lead the league in attendance at the United Center, and fans were excited when the team announced it would build a new 125,000-square-foot training facility and community center in downtown Chicago.

Completed earlier this year, the MB Arena features two NHL-sized ice rinks and other amenities including a fitness center, dining options, and spaces that can be rented for outings and events. The facility is the practice site for the Blackhawks and also hosts youth hockey, adult hockey leagues and public skating.

When plans for the project were unveiled, architects and planners mandated the facility meet or exceed all green and sustainable standards for the city. Chicago has been a leader in promoting vegetative roofs to help control storm water runoff, and this new construction project was no exception. The arena includes the construction of 24,000 square feet of green roof systems to complement the structure’s 68,000-square-foot main roof. A 60-mil TPO system manufactured by Carlilse SynTec was specified for the upper roof assembly, and plans called for an American Hydrotech Extensive Garden Roof Assembly to be placed on two lower sections of the roof.

The Garden Roof Assembly

Architect HOK worked with American Hydrotech during the design stage to select roofing components and plants that were optimized for the climate conditions and the building’s structural limitations.

According to Dennis Yanez, national marketing manager, American Hydrotech, and Kevin Serena, garden roofing technical sales coordinator for the central region, the structure’s metal deck necessitated a lightweight system.

The 125,000-square-foot facility 24,000 square feet of green roof systems that complement the structure’s 68,000-square-foot main roof. Photo: Chicago Blackhawks.

“Our 4-inch extensive garden roof system was ideal for this project,” says Yanez. “Since part of this project had a metal deck, there are more structural capacity concerns than with a concrete deck, so we were able to put together a lightweight, built-in-place system.”

The assembly consists of a hot-applied rubberized asphalt membrane, MM6125, which is applied to the roofing substrate to form a monolithic coating. It is topped with a root barrier and Dow Styrofoam insulation. The system also incorporates Hydrotech’s Gardendrain GR15, a molded polyethylene panel designed to retain water, filter fabric, lightweight growing media, and mature plants.

The plants are installed in the form of the InstaGreen Sedum Carpet, a pre-grown mat that comes in 25-square-foot rolls. It contains between nine and 15 different types of sedum and provides instant coverage when it is installed.

Key benefits of the system include reducing the urban heat island effect, purifying the air, and limiting storm water runoff, notes Yanez. “The Extensive Garden Roof Assembly is able to capture more than 1.5 inches of water on the roof, which plays a major role in storm water management,” he says.

The system also protects the membrane from ultraviolet (UV) degradation and damage from wind-blown debris. “Most importantly, for us, a garden roof is just another version of a PMR, or protected membrane roofing,” says Yanez. “Because the membrane is always in a PMR application, with Dow insulation over it, whatever ballast — whether it’s gravel ballast, or architectural pavers, or the garden roof assembly — is in place makes it literally impossible for the membrane to get damaged. It also mitigates the climate swings, keeping the membrane at a more constant temperature year-round.”

This system has a proven track record, according to Yanez. “We’ve been doing this going back 50 years on parking decks under regular topsoil, where weight wasn’t a concern,” he points out. “This is just a more modern version of that, but we’re putting it on the 4th, or the 14th, or the 99th floor.”

The Roofing Installation

All American Exterior Solutions, Lake Zurich, Illinois, is an approved applicator for both key manufacturers. The union contractor installed the Carlisle TPO system on the building’s main roof and the Hydrotech green roofs on the two lower roof levels.

Willie Hedrick, division manager at All American Exterior Solutions, notes that the TPO roof was installed first. “The deck was acoustic, so first we had to lay strips insulation in the flutes over the entire main roof,” he says.

The lightweight growth media was lifted to the roof in 2-yard totes. Photo: Christy Webber Landscapes.

Areas that housed mechanical equipment were reinforced with two layers of 5/8-inch DensDeck from Georgia-Pacific. Two layers of 2.6-inch insulation were then installed, followed by the 60-mil TPO, which was mechanically attached using the RhinoBond system from OMG Roofing Products. The attachment system uses induction welding technology to attach the membrane to the fasteners and plates that secure the insulation — without penetrating the membrane.

The main roof was originally designed as fully adhered system, but work began in January, and the temperature constraints ruled out some adhesives. “Once we made the switch to RhinoBond, we were able to install the membrane even though we did it during the winter,” Hedrick says.

Most of the TPO roof was surrounded by high parapet walls, and in other areas the safety perimeters were marked with flags. “At a few points at the highest points of the main roof we had to put up some the flags, and if you were outside of the flags you had to be tied off,” notes Hedrick. “The mid-roofs had short parapet walls, and on those roofs, we set up flags and had 100 percent fall protection outside the safety perimeter. For the lower green roof, we put guardrails up on the parapet to eliminate the fall hazard.”

The Garden Roofs

After the TPO sections were installed, work began on the extensive garden roof assemblies. The mid-roof had a metal deck, so the first step was to screw down 5/8-inch USG Securock cover board and strip in the seams. “At that point, we installed the liquid-applied membrane and the protection board,” Hedrick says.

The second green roof was installed over a concrete deck, so the application was a bit different. The membrane was applied directly to the concrete. A late change was made in the configuration of the lower green roof to take advantage of the space. “The owner decided to add a terrace to the lower green roof so people could walk out and see the roof and views of the city,” Hedrick recalls.

Before the growing media and plants were added, electronic field vector mapping (EFVM) was conducted by International Leak Detection to determine if there were any voids in the membrane. “You’ve got to confirm everything is 100 percent watertight before we start setting the components down,” Hedrick says. “We usually do the test and start putting the components down the next day to minimize exposure. The subcontractor we worked with to do the landscaping, Christy Webber, performed well. Since some of the components are loose laid, we worked with them to put down enough soil to hold everything in place. We worked hand-in-hand getting the all of the components and soil in.”

The Landscape Work

Jim Waldschmidt, project manager for Christy Webber Landscapes, Chicago, oversaw the installation of the lightweight growing media and sedum mats on the roof. Christy Webber is a full-service union landscaping company, and Waldschmidt notes that roofing work is a small but growing share of the company’s business. “We work with a few different commercial roofers,” he says. “This year we’ve done maybe 10 commercial projects.”

After the growing media was evenly spread out, the sedum mats were laid into place by crews from Christy Webber Landscapes. Photo: Christy Webber Landscapes.

Logistics at the site made for an easy delivery and setup — an unusual situation in downtown Chicago. “We were able to deliver the soil almost a week before we were scheduled to go out there, so we had everything on site and knew we wouldn’t have to worry about waiting,” Waldschmidt notes. “We just had to bring in a crane and lift up the soil bags. We had a pretty easy installation compared to other green roofs we’ve done.”

Growing media was lifted to the roof in 2-yard tote bags, which were cut open to disperse the contents. Three days after the growing media was in place, Christy Webber crews returned to install the sedum mats. “The sedum mats are delivered on pallets almost like the way a roll of sod would be delivered,” says Waldschmidt. “We just had to set the pallets on the roof, pull off the sedum mats and unroll them.”

A temporary irrigation system was set up to help the plants get established in the hot July temperatures. “Everything looks great now,” Waldschmidt says. “All of the sedum up there is thriving.”

Growth Sector

In this high-profile project, with a high-profile owner, making sure the system was error-free was critical, notes Serena. “Chicago is definitely the leader in vegetative roofs, and has been for more than 10 years,” he says. “This is another prime example. There was never a question whether this building would have a green roof on it. It’s a credit to Chicago, and it is a credit to the Chicago Blackhawks.”

Hedrick is proud to be part of the green roof movement. “I like the challenge, and I like the diversity,” he says. “When the Blackhawks went to the Stanley Cup championship and the blimp was hovering over the arena, I could see a couple of my projects on TV. It reminded me of all the time, effort, attention to detail, and collaborative hard work that it took to produce the final product. We’re turning typically unusable roof areas into useful space for amenities.”

The key driver of green roofs is storm water management, notes Yanez, but turning rooftops into useful space is another key benefit. “We’re seeing more and more city incentives for storm water management,” he says. “In urban areas, people are also taking advantage of existing space with green roofs. It’s a growing industry — pun intended.”

TEAM

Architect: HOK, Chicago, www.HOK.com
General Contractor: James McHugh Construction, Chicago, www.McHughConstruction.com
Roofing Contractor: All American Exterior Solutions, Lake Zurich, Illinois, www.AAEXS.com
Landscape Contractor: Christy Webber Landscapes, Chicago, www.ChristyWebber.com

MATERIALS

Garden Roof System:
Cover Board: Securock Gypsum-Fiber Roof Board, USG, www.USG.com
Membrane: MM6125 hot rubberized asphalt membrane, American Hydrotech Inc., www.HydrotechUSA.com
Protection Sheet: Hydroflex 30, American Hydrotech Inc.
Root Barrier: Root Stop, American Hydrotech Inc.
Insulation: DOW Styrofoam, DOW Chemical, www.Dow.com
Drain Board: Gardendrain GR15, American Hydrotech Inc.
Filter Fabric: System Filter fabric, American Hydrotech Inc.
Growing Media: LiteTop Engineered Growing Media, American Hydrotech Inc.
Plants: InstaGreen Sedum Carpet, American Hydrotech Inc.

TPO Roof System:
Membrane: 60-mil TPO, Carlisle SynTec, www.CarlisleSyntec.com
Cover Board: DenDeck, Georgia-Pacific, www.BuildGP.com
Attachment System: RhinoBond, OMG Roofing Products, www.OMGroofing.com

Pre-Vegetated Tray Designed for Easy Transport and Installation

American Hydrotech introduces the InstaGreenGT-4 pre-vegetated trayAmerican Hydrotech introduces the InstaGreenGT-4 pre-vegetated tray, an expansion of the InstaGreen product line within the Garden Roof portfolio of assemblies. The GT-4 tray is one option for a storm water management plan by providing valuable green space as a best management practice on roofs to handle the first rains. It consolidates all growing media, drainage and vegetation in one convenient package for easy transport and installation by roofing professionals and landscape contractors.

According to the manufacturer, the tray is composed of 100 percent fully recycled content and its 12-inch-by-24-inch high performance format can hold up to 4 inches of media for optimum plant growth. It has a unique reservoir base design for increased water capacity and sustained plant growth in times of drought and perforated side walls to promote inter-tray root growth and water transfer. Integral connector clips are used to form a unified, seamless, vegetated surface and resist wind uplift forces. 

Vegetation options for the InstaGreen GT-4 tray are a standard sedum species blend designed to accommodate the rooftop conditions. A range of perennials can also be added to provide increased color, texture and habitat features for the pre-vegetated roof.

Using Engineered Geofoam for Garden Roofs

For most of the past century, the rooftops of commercial and institutional buildings have largely been places to locate unsightly mechanical systems. Architectural treatments, such as parapets and screens, provide visual relief from such equipment. Now, roofing professionals and building owners increasingly look at the roof as “found space”—a place to be planted and used, instead of hidden.

Facebook’s Frank Gehry-designed MPK 20 building sports a 9-acre green roof using EPS geofoam from Insulfoam.

Facebook’s Frank Gehry-designed MPK 20 building sports a 9-acre green roof using EPS geofoam from Insulfoam.

Throughout the U.S., garden roofs (or living roofs) are growing in popularity with more than 5.5 million square feet installed in 2014, according to Green Roofs for Healthy Cities. Most of that total was for private rather than public projects, indicating this is not just a government trend. In addition to providing attractive and usable open space, garden roofs offer environmental benefits, such as helping to slow and filter urban run-off.

Some of America’s largest companies have installed green roofs. Ford’s Dearborn, Mich., truck plant final assembly building sports one of the world’s largest living roofs at 454,000 square feet. In 2015, Facebook opened its MPK 20 office building in Menlo Park, Calif., with a 9-acre living roof featuring a 1/2-mile walking trail and more than 400 trees.

If you haven’t worked on a garden roof yet, it is likely only a matter of time until you do.

Addressing the Challenges of Garden Roofs

Weighing a fraction of soil, EPS geofoam fill creates ultra-lightweight landscaped features on Facebook’s garden roof.

Weighing a fraction of soil, EPS geofoam fill creates ultra-lightweight landscaped features on Facebook’s garden roof.


Adding plants and park-like amenities to a roof increases the complexity of the roofing assembly. Garden roofs present two primary challenges for roofing professionals to solve: minimizing the dead load and preventing moisture intrusion.

The project team for the Facebook MPK 20 building’s green roof met this two-fold need—and more—with expanded polystyrene (EPS) geofoam.

Weighing considerably less than soil, EPS geofoam is an ultra-lightweight engineered fill that can be used to create contoured landscape features, such as hills and valleys. The material weighs from 0.7 to 2.85 pounds per cubic foot, depending on the product type specified, compared to 110 to 120 pounds per cubic foot for soil.

Despite its low weight, EPS geofoam is designed for strength and has better load bearing capacity than most foundation soils. Geofoam’s compressive resistance ranges from approximately 2.2 psi to 18.6 psi (317 to 2,678 pounds per square foot) at a 1 percent deformation, depending on the product.

The garden roof on Facebook’s MPK 20 building provides ample open space and a half-mile walking trail for employees.

The garden roof on Facebook’s MPK 20 building provides ample open space and a 1/2-mile walking trail for employees.

EPS geofoam is also effective at addressing the second challenge of garden roofs: managing moisture absorption. The moisture performance of the various components in a green roof assembly is critical; retained water imposes additional loads on the roof and increases the risk of water damage to the roof assembly. EPS geofoam meeting ASTM D6817 standards works well here as it only absorbs 2 to 4 percent moisture by volume, even over long-term exposure, and it dries quickly. The moisture performance of EPS has been demonstrated in extensive in-situ applications and real-world testing, including research conducted by the U.S. Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory. After burying EPS in wetted soil for nearly three years, the lab found that the material absorbed only 1.7 percent moisture by volume.

In addition to enabling lightweight, durable landscape features and helping to defend against water, EPS geofoam provides thermal insulation in garden roofs. Roofing professionals have used EPS insulation in roof assemblies for decades because it offers the highest R-value per dollar among rigid foam insulations.

Expect More Demand

Although green roofs currently account for a small portion of the billions of square feet of roofs in the U.S., expect to see more demand for them given their aesthetic and environmental benefits. High-performance materials, like EPS geofoam, can help provide a long-lasting, durable green roof assembly.

PHOTOS: Insulfoam

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.

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

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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.

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Downtown Storm-water Management

Founded in 2002, Xero Flor America (XFA) is the official U.S. distributor of the Xero Flor Green Roof System. XFA has made its home in Durham, N.C., since 2006 when the company relocated its national headquarters from Lansing, Mich. In July 2012, it moved locally into renovated offices in The Republik Building, located at 211 Rigsbee Avenue in downtown Durham’s historic district.

Originally constructed in the 1940s for the Durham Insurance Service Co., The Republik Building is perhaps known to local history buffs as the home of WSSB radio. Robert Shaw West, chairman and CEO of The Republik, a local firm offering brand strategy and communication services, purchased the property from the city of Durham. He renovated the outmoded offices into a more contemporary, open and collaborative work environment in 2006. XFA decided to become more connected to the business community downtown and searched for offices in the historic district—ideally in a building where the company would have the opportunity to showcase its green roof system. West had space available on the second floor for XFA to lease.

Completed in February 2013, the 2,343-square-foot Xero Flor green roof atop The Republik Building is the first green roof installed on a building in Durham’s downtown historic district.

Completed in February 2013, the 2,343-square-foot Xero Flor green roof atop The Republik Building is the first green roof installed on a building in Durham’s downtown historic district.

“It was serendipity,” West says. “Xero Flor was looking for offices downtown, and we had space. Plus, we had to reroof our building last year. Since we needed a new roof, it was an ideal time to also consider adding a green roof, which supports our commitment to sustainability.”

Completed in February 2013, the 2,343-square-foot Xero Flor green roof atop The Republik Building is the first green roof installed on a building in Durham’s downtown historic district.

Going Green on the Roof

In addition to the standard building-permit process, putting a green roof on a historic building required additional review and approval.

According to Anne Kramer, urban designer with the Durham City-County Planning Department, except for certain minor items, such as repainting a previously painted surface, most changes to building exteriors within an official historic district require a Certificate of Appropriateness (COA). The Durham Historic Preservation Commission oversees the process locally.

The commission’s goal is to ensure preservation of the architectural character of the historic district’s buildings and, therefore, had to ensure adding a green roof to the building would not alter or disrupt the appearance of downtown Durham. Demonstrating a green roof would not be visible from the street level was especially important. With the COA from the preservation commission, XFA and The Republik had the green light for the green roof. But first Baker Roofing, Raleigh, N.C., installed the new structural roof.

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