New design techniques for green building are continuously examined by architects and engineers. Some new designs reap greater rewards than anticipated; others create challenges when they don't work as planned.
In a field with ample room for exploration, architects are eager to share successes and disappointments as a way to secure a reliable set of sustainable guidelines.
In a seminar based on commercial green building best practices, Eric Truelove, director of sustainable design with The Renschler Company, used case studies from recent projects he completed to present strategies and lessons learned for developing successful green, sustainable projects.
Factors considered in all projects included proximity to mass transportation, dual-flush toilets, recycled content of building materials, good building seals, nonchlorinated sealants, exhaust of critical areas, outdoor air systems, outdoor lighting and more.
Rain guards and irrigation for plants were an important element, as well as white roofs and natural vegetation. However, in highly arid areas that receive few inches of rain per year, it can be challenging to create an effective water collection system.
Lidia Berger, eastern director of sustainable design services for engineering and architectural firm HDR Inc., also discussed successful and challenging design practices.
In a project the firm recently completed, the LEED platinum-certified Banner Bank in Boise , Idaho , lack of rainfall encouraged designers to get creative and tap into other resources. A water reclamation system provides the majority of the water needed for sewage conveyance by collecting lavatory graywater and urban storm water from seven acres of off-site downtown hardscape. However, rainwater can cause problems with separation issues.
“Some of our rainwater came from parking lots and there's a lot of nasty stuff in it,” Berger says.
Another unique aspect of Berger's project is the use of structural supporting beams that feature hexagonal spaces that increase the beam's depth by 50 percent, thereby creating large open floor plans.
A raised floor allows for underfloor air distribution and all plugs and switches to be in the floor rather than along the walls. The HVAC system delivers air to multiple point-of-use locations throughout each floor while distributing electricity and telecommunications outlets with greater flexibility.
“Every light is controlled by occupancy sensors in the ceiling, which can help decrease use of lighting by 65 percent,” Berger says. Reduced operating costs contribute to a $1.47 million increase in asset value and a 32.4 percent return on investment.
LEED's stringent guidelines can offer big payoffs, but the USGBC could offer more flexibility, Truelove says. Fewer than 20 buildings in the world have achieved LEED Platinum. He believes that the certification process could be accelerated and guidelines could be expanded to include more design elements.
“We need a green building rating system that can be applied to 80 percent or more of commercial buildings,” Truelove says.