Green building LEEDs the way

Solar panels

Courtesy Wickipedia Commons

 

by Eamon T. Geary

Constructing and operating buildings consumes enormous amounts of energy, water, and materials, and creates vast amounts of waste. In the United States, buildings use 65% of electricity, consume 30% of raw materials, emit 30% of greenhouse gases, and annually generate over 136 million tons of waste. Because of this, the construction of residential and commercial buildings profoundly affects our environment. But the good news is that by building green, we can greatly reduce these ecological impacts.

The fundamental concepts behind green building are simple: build in a manner that least impacts the natural environment and provide a healthy indoor space for occupants. Green builders consider everything from the location of the building to the materials used, and ask questions such as: “Is this structure near existing public transportation and sewer lines? Can we reduce the need for lighting fixtures and energy use by incorporating more natural daylight and using paint that reflects light? Can we use paint and carpeting that emit no volatile organic compounds? Will the landscaping increase or mitigate the site’s stormwater run-off?”

Sustainable design practices have been around for millennia. The Hopi Indians used clay plasters to modulate moisture and temperature, while the ancient Greeks built cisterns to capture and re-use rainwater. Many of these ancient techniques are now being embraced by today’s architects. Green Building materials typically include products that are nontoxic, reusable, renewable, and recyclable. They also include renewable plant materials like straw and bamboo. Bamboo, which can replace traditional sources of wood, is a highly renewable resource as it can be harvested for commercial use after only six years of growth. Other low-impact building materials include insulation made from recycled denim or paper, organic and milk-based paints, lumber from forests that are sustainably managed, and recycled metal. Also, whenever possible, green building materials are extracted and manufactured locally to minimize the energy required to transport them. For example, if a new structure is being constructed in a wooded area, wood from the trees which were cut to make room for the building would be reused as part of the building itself.

Architectural salvage and reclaimed materials are also used. When older buildings are demolished, good wood is now often reclaimed, renewed, and sold as flooring. By using salvaged doors, windows, mantels, and hardware, the consumption of new goods is kept to a minimum.

An array of green building standards exist, but the most commonly used framework for assessing the degree of a building’s “greenness” is the Leadership in Energy and Environmental Design (LEED) system, which has emerged as the de facto green building code. Developed through a consensus process involving architects and other building professionals, the LEED system is the nationally accepted benchmark for the design, construction, and operation of high performance green buildings. LEED points are awarded for meeting standards in five categories: site selection, energy and pollution, water efficiency, indoor air quality, and materials. For example, a project scores points for site selection if it is located along bus and trolley routes to encourage the use of mass transit. To earn certification, a building project must meet certain prerequisites and performance benchmarks within each of the five categories. Projects are awarded Certified, Silver, Gold, or Platinum certification depending on the number of credits they achieve.

Initially, LEED was developed for newly constructed commercial and institutional buildings, but as the popularity of green building grew, the system was expanded. Today LEED offers green standards for existing buildings, which reward owners for upgrading building systems; for commercial interiors, which reward tenants for making green choices in the areas of a building where they control the design; and for speculative office buildings, which reward developers who make green choices when designing a building’s shell and core operations. Pilot programs are now under way for LEED systems for use in neighborhood development, homes, schools, and retail areas.

Because they require less energy and water, green buildings can significantly reduce operating costs. Despite this, builders often shy away from green construction because they believe it will cost considerably more than conventional construction. However, the average cost difference is only about 5%, an amount that is quickly returned in cost savings that include lower energy, waste disposal, and water costs, lower environmental and emissions costs, lower operations and maintenance costs, and savings from increased productivity and health.

Eamon T. Geary is Project Specialist with the Green Building Alliance at www.gbapgh.org.

Published November 2007