Green roofing project demonstrates leadership
For commercial building owners and managers who are considering eco-friendly roofing options for their new or reroofing applications, terms like “solar reflectivity,” “sustainable design” and “photovoltaic arrays” have moved from ambiguous ideas to the focal point of discussions with their construction partners.
March 17, 2009 By Rob Colman
Helping building owners shift from the idea stage to better informed decision makers was part of the strategy behind a full-scale “green renovation” project undertaken by Chapman Construction/Design, a construction management firm in Newton, Mass.
Beginning in late 2007 and completed in September 2008, Chapman served as designer, green consultant and construction manager for a multi-phased, interior and exterior renovation of its own office building.
Following the rigorous technical standards of the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, the firm set out to achieve LEED Platinum certification from the United States Green Building Council (USGBC). Platinum is the highest rating level of LEED certification, the North American benchmark for the design, construction and operation of high performance green buildings.
The ambitious renovation project included:
- Energy-saving modifications to its mechanical systems;
- Replacing plumbing fixtures with high-efficiency alternatives that the company estimates will help reduce water consumption by 40 per cent or more;
- Installing skylights and additional windows to allow more natural light into interior spaces, which will cut Chapman’s lighting power density by 35 per cent;
- Salvaging and re-using doors, lighting, metal studs and masonry whenever possible; and
- Using sustainable products, such as recyclable carpet tiles, low-VOC paint finishes, bamboo, cork and Forest
- Stewardship Council certified lumber.
However, the centerpiece of Chapman’s green renovation initiative is a new 47 kW (DC) photovoltaic (PV) solar power array installed on its rooftop. Comprised of 208 panels, the SunPower SPR-225 system is designed to produce 55,000 kWh of clean power per year, which will supply 90 per cent of the company’s electric power needs.
The PV system is grid-connected and sends excess power back to the utility during times of peak production. Chapman estimates its electricity cost savings in the first four to five years will approach US$50,000, or US$10,000 per year.
“Installing this PV system allows us to shrink our carbon footprint, conserve resources and become nearly self-sufficient by providing our own energy needs,” said Guy Compagnone, Chapman’s director of sustainable practices and one of approximately 25 per cent of the company’s employees who have earned the LEED
Accredited Professional (AP) designation.
Like any aspect of construction management, a cost/benefit analysis still applies to environmental stewardship decisions. Based on the grant it received from the Massachusetts Technology Collaborative and combined with federal/state tax credits and incentives as well as its reduced electrical load, Chapman anticipates the system will pay for itself in five years. With an estimated 40-year life span, the PV system will provide Chapman with 35 years of free power.
“While the environmental benefits of green building are obvious to most people, the financial benefits can be just as compelling,” Compagnone explained. “Too often, people assume building green is expensive, while the reality is not building green is always more expensive in the long run.”
Beyond solar power
Although the entire roof surface totaled only about 15,000 square feet, the facility consists of three buildings grouped together with separate roofing systems. All three roofing systems were manufactured by Firestone Building Products Company, LLC and installed by Roberto Bros. Roofing, Wakefield, Mass.
To further enhance green building principles, three sections of the PV system were installed above a new, highly reflective, white thermoplastic polyolefin (TPO) single-ply roofing system. The two remaining sections were installed over an existing EPDM roofing system that was top-coated with Firestone’s white AcryliTop coating, which exceeds the Environmental Protection Agency’s (EPA’s) Energy Star requirements
for energy efficiency.
According to Tony Roberto, managing director of Roberto Bros. Roofing, “We installed the existing Firestone fully adhered RubberGard EPDM roof about eight years ago and it was in good shape, so a reflective acrylic coating was added to help reduce cooling loads.”
The high solids, acrylic-based coating provides roof membrane protection to prolong roof life cycles and reflect solar radiation. Applying a light-colored coating over a dark-coloured roof also can help reduce the “thermal shock” stress associated with large temperature variations on rooftops.
The roofing system on the other sections consisted of 1.5mm (60-mil) Firestone UltraPly TPO membrane fully adhered over two layers of 50mm (two-inch) thick Firestone ISO 95+ polyiso insulation. Although the roof decks are adjacent to each other, the project involved two separate installations.
On one portion of the building, Roberto Bros. recovered an existing built-up roofing system with the TPO system. And, on the other area, Chapman reframed the deck to enclose the structural steel that carries the array, and Roberto Bros. then installed new polyiso insulation and the fully adhered TPO membrane.
“The biggest benefit of using Firestone’s TPO roofi ng system on the Chapman building was the installation ease,” Roberto said. “Hot-air weldable seams are fast and easy for our installation crews, and the wide membrane sheets simplified the whole process for us.”
Thermoplastic single-ply roofing membranes are the fastest growing segment of the commercial roofing industry. TPO roofing membranes have gained broad industry acceptance for their many environmental, performance and installation advantages. In addition to its excellent reflective properties, Firestone Ultra-
Ply TPO membrane offers superior ozone and chemical resistance. It also qualifies for LEED Sustainable Site credit 7.2 (SSC 7.2) and has earned the Energy Star label.
Products that carry the Energy Star label have been certified by roofing manufacturers to lower roof surface temperatures by up to 370C (100 degrees Fahrenheit). By incorporating both a white acrylic coating and the white TPO roofing systems into the project, the increased reflectivity lowers the roof temperature during air-
conditioning and reduces the amount of heat conducted into the building, thereby reducing cooling costs.
Once the EPDM and TPO roofing systems were complete, Chapman staffers — both field and office personnel — volunteered to participate in a modern day “barn raising” to gain practical training in PV installation. Chapman used the PV roofing installation as an opportunity to further its employees’ understanding of green construction, so they could better support customer needs.
A rooftop observation deck will enable Chapman to give visitors an up-close look at the new green roofing systems. Similarly, Chapman’s new first-floor lobby includes a display wall highlighting the many cost-effective sustainable materials used to help meet the LEED Platinum status.
“The project is the perfect training ground for our employees and has become a learning lab that deepens everyone’s understanding of LEED requirements and green construction,” said Chapman President and LEED AP John Hall. “It allows them to put into practice what they learned in company-sponsored seminars and LEED AP exam study groups. Overall, it is a huge benefi t to our clients as we can better illustrate the advantages of looking beyond initial costs and, instead, consider the impact of a building throughout its life cycle.”
And, although Chapman believes LEED certifi cation is important, it also recognizes there are lots of ways to go green and does not mandate LEED when working with its clients.
Michael Bassichis, director at The Margaret Gifford School in Weston, Mass., explained how the recent renovation project helped them better understand the advantages of green building.
“Over the course of more than a decade, Chapman Construction/Design has transformed The Gifford School into one of the premier sites for providing the school for children with moderate to severe special needs,” he notes. “Now having recently visited Chapman’s green renovation, we are exceptionally interested in putting solar panels on our gymnasium, and Chapman is also conducting a green audit of the rest of our campus.”
Because no two construction projects are alike, Chapman developed a “Green Pyramid” that arranges green strategies from easiest- to hardest-to-implement. It begins with creating a green mindset through internal education and ascends to areas such as recycling construction debris, improving indoor environmental quality and incorporating renewable energy systems like PV roofing, wind turbines and geothermal energy sources. Throughout each level, Chapman provides examples of typical investments (e.g. increased ventilation, daylight and views) and potential returns (e.g. increased employee productivity and retention).
As part of its effort to educate clients about the value of going green, Chapman also developed a green budget spreadsheet. Every client budget includes an a la carte menu of green options. Some items are included in every project at no additional charge, such as sorting and recycling construction debris and providing clients with a report detailing how much of the debris was recycled. Other line items include a list of utility company incentives that offer rebates for choosing certain light fixtures.
While Chapman’s LEED Platinum renovation project was no small undertaking, it squarely demonstrates the company’s green philosophy and commitment to sustainable construction practices. More important, it validates their desire to inform and educate their employees as well as other building professionals about the
benefits of going green.
This is an edited article provided by Firestone Building Products. For more information visit www.firestonegreen.com.
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