What’s a green home? If you’re in the market for a new home, you should be asking for a green home, one that, at a minimum, saves at least 30% of the energy of a conventional new home, has water­-conserving fixtures and uses non-­toxic finishes. Increasingly, regional and national homebuilders are offering such projects. A recently completed Northern California proj­ect by Lennar, one of the ten major US homebuilders that deliver about 35% of all new single­-family homes, shows this potential. The project in Roseville will integrate photovoltaic systems and upgraded energy­ efficiency measures into 450 new homes slated to be built over the next two years in cooperation with Roseville Electric, a city-­owned utility. The PowerLight SunTile® solar electric system, a roof-integrated technology, will be installed as a standard feature on each home, resulting in significant utility bill reductions for the homeowners, and the generation of completely emissions­-free electricity. In addition, by reaching certain en­ergy­ efficiency goals, the Lennar-­built homes may qualify (through 2008) for a $2,000 federal tax credit.

Cannon Beach home, NAHB Green Custom Home of the Year, 2005, is also a zero-­net­-energy home, built in accordance with advanced ecological design principles. Design by Nathan Good Architect. (Photo by Dan Morrison, courtesy of Fine Homebuilding Magazine)

Another project by a well­-established regional builder is Carsten Crossings in Rocklin, California (near Sacramento), built by The Grupe Company. This project was LEED-­certified by the LEED for Homes pilot program. The homes are more energy efficient than the exacting Califor­nia state requirements and also include onsite solar electricity that can re­duce electrical bills by up to 70%. Standard energy­-saving features also in­clude tankless water heaters, “low­-e” windows, enhanced attic insulation and foam­-wrapped building envelopes.

What makes a home green?

• It should save at least 30% of the heating and cooling energy of a con­ventional home through additional insulation, better glazing, better construction methods, exhaust-air heat recovery (in cold climates) and more-­efficient HVAC systems.
• It should be built according to an established rating system such as the NAHB model Green Home Building Guidelines (or their local home­builder association or utility equivalent),ENERGY STAR or LEED for Homes.
• It should be certified by an independent third party using the chosen rating system.
• It should supply some of its energy from renewable sources, either solar hot water or photovoltaics.
• It should save water with water­-conserving fixtures such as dual­-flush toilets.
• All appliances should be ENERGY STAR rated.

The Helena apartments, New York City, designed by FXFOWLE ARCHITECTS, PC (Photo courtesy of FXFOWLE ARCHITECTS)

There are custom homes that take the concept of a green home even further, by having a green roof, 100% of energy supplied by photo­voltaics and solar thermal systems; using only FSC­-certified wood products; using recycled­-content, salvaged and locally sourced mate­rials throughout; in essence trying to get as high up on the LEED for Homes rating scale as possible. Such homes include homeowner education to maximize the effec­tiveness of the energy conservation and water conservation systems. Shown at left is a custom home in Cannon Beach, Oregon, that re­ceived the NAHB Custom Green Home of the Year award in 2005. Its design also incorporated The Natu­ral Step principles (see section on the Ecological Footprint), which was very important to the home­owners.

Elsewhere, we have described projects by developers that include mid-­rise and high-­rise condominiums and apartments. For any building above three stories, the LEED for New Construction (LEED­NC) rating system can be used to assess a green residence. Several dozen such residential proj­ects have already been certified under the LEED­NC rating system, includ­ing a Portland apartment building that received a LEED Gold certification in 2007. The nicest feature of this apartment, in which my wife and I were among the first tenants, was the healthy indoor air quality, including the fact that this was a non­-smoking building.