In the past 10 years, a good deal of attention on energy efficient buildings was generated in the Denver, CO metro area. Activists and forward-looking elected officials have helped boost Denver to the 7th Most Energy Efficient City, according to recent E.P.A. ratings.
Energy efficiency is the cheapest way to reduce greenhouse gas emissions that are forcing the climate system. Given recent scientific papers detailing more rapid warming of the planet, I think Energy Star buildings should be made mandantory by municipalities.