“But not all housing is created equal, and making retrofits in some of the least efficient buildings could have a much bigger impact on emissions than fixing up buildings that already perform relatively well,” says the release. “Figuring out how to identify the buildings most in need of improvement, however, at a scale useful for city officials and utility companies, is not a simple task.”
Professor González uses 82 different parameters that can have an effect on the overall thermal efficiency of a building, she says, which makes assessing the problem very difficult and especially if it is a city-wide effort. But she goes on to say that the MIT team has found that only eight such criteria are essential — and that the research will be “almost as accurate” but a lot more practical.
“My work is about reducing the number of variables you need to know,” González says. “Is there a way to do urban planning without knowing all the details?” And in this case, she and the team found, there is indeed. The factors they isolated, she says, “are the variables that matter. You can really concentrate on those eight.”
Professor Ulm adds that three factors alone can provide as much as 90 percent of the information that analysts need.
The key to making useful assessments turned out to be a direct measure of people’s energy use during cold months: their monthly gas bills, says the release. Some steps to create efficiency: adding insulation, sealing leaky windows and doors, and replacing older single-pane windows with newer double-pane versions.