A lot of attention has been given to green building lately. With that attention has come some confusion about what precisely green building is. Other terms, like “healthy” building, “natural” building, and “sustainable” building, or development, also add to the confusion. This is a complex topic that we will try to clarify in today’s “Power Play” and in the Nov. 11 “Power Play.”
In a nutshell, green building strives to provide healthy, comfortable interiors for building occupants; to maximize operational savings through efficient use of water and energy; and to maximize the positive impacts of development on the natural environment, including reducing suburban sprawl, making more efficient use of existing developed areas, and cleaning up previously polluted sites.
Most buildings have the potential to become greener when remodeling – from commercial or multi-story apartments to single-family homes. Major green building categories are water and energy efficiency, indoor air quality, site design and solar orientation, building material choice, and operational and maintenance considerations.
For larger developments, the most energy-efficient measures include locating a building on a relatively small “footprint” on the site, which means going up, not spreading out. This does a number of beneficial things, including covering less ground and allowing rainfall to soak into unpaved areas, and reducing the amount of energy needed for heating by having common floors and ceilings between units that help insulate each other. It also reduces cooling loads on the building, since there is more exterior wall space to incorporate operable windows.
With operable windows and interior ventilator stacks for natural ventilation, occupants are able to adjust the air freshness and temperature to suit their own needs without using air conditioning. This measure reduces up-front costs for the builder and eliminates the air conditioning expenses for building occupants. Berkeley is fortunate to have an excellent climate for natural ventilation.
Larger buildings located near public transportation, shopping and schools will reduce transportation costs for building occupants, eliminating a major source of pollution – driving. For every gallon of gasoline burned, 20 pounds of carbon dioxide equivalent (CO2e – a mixture of greenhouse gases) is produced. For example, say that 30 Berkeley residents commute 27 miles round trip to work. Driving in vehicles that got a generous 27 miles per gallon, they would release 78 tons of CO2e annually in a 27-mile daily commute. If these residents used public transportation, they would generate less of CO2e and reduce traffic congestion as well.
If those 30 residents had to commute 80 miles round trip each day from the suburbs, they would generate 234 tons of CO2e annually. The news is worse if their vehicles only get 18 or 20 MPG, as many SUVs do. Eliminating the need to commute great distances is the fastest and easiest way to reduce pollution, reduce our reliance on imported oil, and improve air and water quality for all Bay Area residents.
Using non-toxic building materials is another aspect of green building. Sometimes called “healthy” building, their construction materials and interior finishes are free of the toxic ingredients that traditional building materials have. Buildings constructed with non-toxic building products have far better indoor air quality and are healthier for the building’s occupants, as well as the workers who manufacture the building products.
Formaldehyde is used in plywood and wood composite boards, urea-foam insulation, and permanent-press fabrics such as drapes and upholstery. These materials continue to emit formaldehyde gas for as many as ten years, especially when exposed to heat or direct sunlight. Switching to solid wood trim and cabinets instead of MDF (medium density fiberboard) will also help improve indoor air quality. It is also safer for workers to use.
Vinyl emits polychlorinated biphenals (PCBs) and dioxin, which according to the EPA is “one of the most toxic and environmentally stable tricyclic aromatic compounds of its structural class,” meaning that it does not break down easily in the environment. Vinyl building products include windows, siding and flooring, PVC pipes, adhesives, and vinyl shower curtains. Vinyl windows and siding are exposed to direct sunlight, which increases their rate of dioxin gas emission.