Opinion: Want to phase out fossil fuels? We must fundamentally change our buildings.

Just about everybody understands that getting off fossil fuels is central to our climate goals. What few people understand, however, is that we won’t be able to do it without fundamentally changing our buildings. Buildings consume an average of about 40 percent of U.S. energy. And in some cities, that number is much higher — upward of 70 percent. Local governments are attempting to address this by passing legislation that would require building owners to reduce emissions from their energy use. Local Law 97 in New York City, for example, requires them to reduce greenhouse emissions by 40 percent by 2030 and by 80 percent by 2050. Those who don’t hit the target could face massive financial penalties.