An increasing number of cities are improving building efficiency in response to legislation or pressure from green organizations. Many are working with the U.S. Green Building Council to leverage the council’s LEED certification system, which codifies steps that can be taken in new and refurbished buildings to minimize environmental impact. Attaining LEED certification “isn’t niche anymore, it’s mainstream,” says Marie E. Coleman, council spokesperson.

Some cities are even incorporating measures from LEED into their building codes to force change. “We went through the building code word by word,” says Lora-Marie Bernard, executive director of the council’s Houston chapter. “Making it stricter, by using things like cool roofs and Energy Star, creates a brand-new landscape for this industry.”

The U.S. Environmental Protection Agency also added a spotlight on municipal efforts in March, when it released a list of the 25 cities with the most buildings certified as energy-efficient by the agency’s Energy Star program. Number one was Los Angeles, with 262 buildings. San Francisco was second with 194 buildings. Rounding out the top 10 were Houston; Washington, D.C.; Dallas–Fort Worth; Chicago; Denver; Minneapolis–St. Paul; Atlanta; and Seattle.

Note: This article was originally printed with the title, "Greenest Skylines."