A study commissioned by a British architectural firm finds traditional buildings are more eco-friendly than modern ones with lots of glass.

Atelier 10, an environmental engineering firm, compared two computer models, one of an old-style building with less than 40 percent of its exterior glass and the other with glass walls on south and north faces. The researchers found the more traditional building would cost 15 to 20 percent less to heat in the winter and cool in the summer, The Telegraph reported.

"Actually the architectural establishment do know this but they don't want it said -- that traditional buildings are more sustainable," said Robert Adam, the architect who commissioned the study. "Environmental engineers know this too but they tend to work for architects. This is the great secret that no one wants to reveal."

Robert Adam Architects, Adam's firm, specializes in traditional buildings.

Copyright 2007 by United Press International

Explore further Two pairs of specs in one: Touch of finger changes prescription