'Green' buildings are hot - and cool

It's the perfect "green" building.
It faces south, taking advantage of passive solar features. Its east and west ends are insulated with a mountain of limestone. It stays cool in summer, warm in winter.
It is made from materials that are found nearby or manufactured on-site and recycled generation after generation.
No commute. The work site is on-site or a stone's throw away. Food and water are available nearby.
It is the perfect zero-carbon home, though nobody has lived in it for centuries.
Still, we can learn something from the cliff dwelling, says architect Dave Burns, who has spent much of his professional career trying to approach the sustainability of our ancestors in buildings that must be air conditioned, lighted and powered for the various jobs they perform. He is spending his time now persuading others to go along, forming a Southern Arizona chapter of the U.S. Green Building Council.
The crusade for greener buildings has accelerated with the recognition that powering our homes, offices and factories requires 70 percent of the electricity generated in this country and accounts for 30 percent of our contribution to climate change — the release of greenhouse gases caused by our daily activities.
The modern green building is an amalgamation of those early lessons and high-tech systems.

Site planning

Oriented mainly toward north and south with shade configured to warm the building in winter, cool it in summer. Breezeway allows outdoor classroom, and two-story design minimizes building footprint.
Water management
Rainwater captured from roof irrigates native or adaptive plants, and excess is directed to nearby recycled-water pond in Reid Park; toilets are flushed with recycled water; gray water from sinks and showers is used for on-site watering.
Building also has waterless urinals, ultra-low-flow faucets and a pervious-concrete in parking lot, which allows rain to seep back to water table.
Energy management
Solar panels provide shade and generate at least 20 percent of the building's energy needs. Skylights and windows provide "daylighting," reducing energy demand. Lights, heating and cooling adjusted to reduce use in sunny and warm areas of the building. White reflective roof, insulated-concrete-form walls with average R-32 insulative properties, double-paned, low E glass. HVAC system downsized to 35 percent of energy that would otherwise be required.
Material use
Made on site: rammed-earth patio walls. Concrete and asphalt on site was ground and recycled for new paving. Recycled fly ash in new concrete. Most building materials manufactured within 500-mile radius.
Recycled: Originate Natural Building Materials donated a salvaged countertop of Ice Stone, a totally recycled product. Window shading salvaged from former Tucson General Hospital; cotton batt insulation made from recycled jeans in Chandler; linoleum flooring made from scrap wood and sawdust; Trex decking and carpet made from recycled plastic. Steel frame is 99 percent recycled; 90 percent of construction debris was sorted and recycled.
Rapidly renewable materials: Bamboo; wood from certified renewable forests.
Commuting
Located along multiuse paths with bus line nearby. Showers (of limited duration) in restrooms and bike lockers to encourage bike use by staff. Parking set aside for car pools and alternative-fuel vehicles.
Indoor environment
All paints and adhesives are free of volatile organic compounds. Operable windows allow fresh air to circulate (and reduce heating and cooling needs) on balmy days. Plywood and particle board used in construction are formaldehyde-free. Carpet doesn't give off gas. Green-cleaning program uses environmentally friendly products.
Other
White roofs, shade trees and light-colored paving reduce heat-island effect. Tucson Zoological Society will purchase "green" energy credits comparable to four years' operation of building. The building and its resource-saving components will become part of the Zoo School's education about conserving resources. Vegetation removed was fed to the zoo animals. Animals will snack in the future on bamboo grown on-site.

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