The difference between site and source energy is a vital concept to understand when looking at the energy performance of buildings—failing to account for the difference will result in an apples-to-oranges comparison that does not give the true picture of a building’s energy consumption. This document explains how these two types of energy are accounted for differently and why. Read more...

In America, there are around 58 million houses that were built before the last energy crisis. Because these pre-1970s houses have little or no insulation, they are all ripe for energy-efficiency improvements. Houses eat up 20% of the energy used in this country and account for 21% of the carbon dioxide that contributes to global warming. This adds up to a huge opportunity. America's old houses can be made much tighter and can even approach net-zero energy use. Here, I'll highlight three houses that my company, Building Science Corp., has renovated. Each house had different limitations and learning curves. I share one of the houses with my husband and business partner, Joe Lstiburek, and two of them have been used as our office space. Renovating an old house is an expensive process. It's also a delicate process because the end product must retain its charm. Read more...