Washington Post: New Mexico architect Edward Mazria has a proposal to reduce the greenhouse gas emissions that contribute to global warming. His target: buildings. Most people do not connect the two, but in the United States, buildings are the largest source of greenhouse gases. And half of these buildings are houses. About 25 percent of building-related greenhouse gas is produced on-site by fossil-fuel-burning furnaces and water heaters. The rest is produced off-site by the local utility …