Selecting green products for new hospital construction can have a positive impact on patient outcomes and the productivity of its medical staff. Therefore, the owners of the 12,000-square-foot LEED-certified hospital within Washington state's Gateway Medical Center specified the hospital’s building envelope with great care, including a durable ENERGY STAR single-ply roofing system from IB Roof Systems. “The folks at the medical center are concerned about the health of their future patients,” said Project Manager Michael Gage of Columbia Rim, the project’s contractor and builder. Having a quality product on the roof gives the staff the opportunity to concentrate on what they need to focus on the most: patient care.

The Prescription

The hospital’s roof is low slope with a mechanical attachment system. The IB Roof Systems membrane has a CPA (copolymer alloy) package of Nitrile rubber plus other modifiers that provide a high level of resistance to the contaminants that can land and collect upon an outdoor surface. The CPA formulation also has the highest resistance to UV light available for increased weather resistance. Decking membranes allow for ease of maintenance while meeting ADA-approved (Americans with Disabilities Act) standards. Exceeding hospital construction requirements, the roof is a Class-A fire rated product, which does not support combustion. The IB Roof system also came with pre-engineered products for addressing roof penetrations. “The roof has a 25-year warranty and may even outlast the building itself,” said Ed Cook, IB Roof sales representative.

Checking Temperatures and Energy Levels

In addition to durability, the cool roof portion of a building envelope offers energy efficiency by reducing the heat island effect, which is a desirable design feature in LEED buildings. Heat islands are present in urban areas where “heat sinks” store radiant heat from the sun and magnify local warming by several degrees compared to rural areas. Because a cool roof product remains below 91 degrees Fahrenheit during the hottest hours of the day, it protects against the higher temperatures typical of urban areas and decreases the need for heavy air-conditioning use during periods when utilities often charge a premium for electricity from the grid. Even though the heat doesn’t get extreme in Washington, it’s an added feature of protection. Additionally, the medical center’s building team outfitted the HVAC units installed on the roof with a filtering system for improved air quality inside. “They’ve installed highly efficient, high-energy units,” Gage said.

The Gateway Medical campus has three buildings; two gained LEED gold certification. These LEED core and shell projects are very energy efficient and have high environmental performance. The campus was ENERGY STAR-rated for even more LEED points. “The roofing membrane was one portion of our LEED building construction, which helped achieve over 18-percent energy savings over typical building construction,” said Mark Bottemiller, architect from Columbia Rim. “It was simply chosen because the roof creates a more energy-efficient building and improved our points for LEED rating.” The reflectivity of an IB Roof membrane can assist a project team in meeting and exceeding the prerequisite ASHRAE 90.1-2004 energy-efficiency benchmark in LEED. The hospital exceeded the LEED prerequisite for energy efficiency and also gained points in the EA credit for optimized energy performance.

Energy savings from cool roofs is also good public policy, according to the building team. But a good public perception is nothing without data to backup claims. The hospital owners wanted to know how well the building performed in an ongoing manner for energy performance as well as safety. “The system is so elaborate that temperature readings can be accessed from a computer,” Gage explained. “A report on all the relevant parameters of building safety go to a computer, and it [the computer] sets off a signal to the fire company if a high CO level is recorded.”

Sustainability Tests

The reduced energy and environmental impact of the roof was just one of the ways the hospital gained LEED certification. “One of the things we are proud of is that we’ve reduced our water usage to meet the LEED requirements by 25 percent,” Gage said.

“Recycled materials were used,” he continued. “For a LEED Innovation in Design credit, we used 20-percent regional materials with recycled content.” In the LEED Materials and Resources Credit category, the IB Roof System can potentially contribute to the recycled content and regional materials credits. For example, new advances in vinyl recycling can divert roofing membranes from disposal in landfills while producing a source material for new products. And, the IB Roof manufacturing facility was within 500 miles of the construction site for assistance with regional materials LEED credits.

In other LEED categories, the roof has a storm runoff system that meets the LEED Sustainable Sites credit requirements. Stormwater runoff from the roof enters an intensive storm filtration system on the medical campus for improved water quality leaving the site as runoff.

The Prognosis

From the Gateway Medical Center’s roofing membrane, which is durable and has improved potential for reuse and recycling, down to its reduced environmental footprint and an energy-efficient design, the medical community working under its roof can focus on the most important thing: the health of their patients.