Ever noticed a draft coming from your windows on cold winter days? If so, weatherproofing your windows is an extremely low-cost way to improve the comfort and energy efficiency of your space.

Dorm residents at Harvard Law School’s North Hall sometimes noticed cold spots near their windows on chilly days. Though it is a LEED Gold-CI building, that doesn't mean there isn't room for energy efficiency improvement!  HLS' Green Living Representatives knew that leaky windows not only let cold air in, but they let our conditioned air out, resulting in significant energy losses. So, HLS weatherproofed all 117 of North Hall's windows with one-sided sticky foam tape that creates a tight seal when windows are closed to prevent air from escaping, while still allowing the windows to open and shut.

The result? A more comfortable space for our dorm residents, and energy savings for HLS. This project is expected to save $1006 each year and 4 metric tons of carbon dioxide equivalents, achieving a 2.15 year discounted payback and 55.6% internal rate of return including the cost of labor and materials.  HLS estimated these cost and GHG savings using the Harvard Life Cycle Costing Tool, an open resource that helps project managers analyze life cycle costing for energy conservation measures.