Why weatherize your property’s basement?
Whether or not your rental property’s basement is a living area, it’s important to make sure it is properly sealed and insulated to help minimize heating demand throughout the building. Addressing the basement may also help avoid common moisture and pest entry problems.
A no-cost energy assessment can evaluate the entire building, from basement to attic, to show you how to boost your rental property’s overall energy efficiency. Energy experts can offer energy-saving products for you to install, suggest upgrades, and if necessary, help coordinate air sealing and insulation services with weatherization installers.
These professionals have a trained eye for spotting common sources of air leaks. However, the most comprehensive way to find hidden leaks is through a professional assessment using a blower door. This device pressurizes your building to reveal leaks. While a blower door test isn’t typically included in a complimentary Mass Save energy assessment, it’s often worth making the investment of $300 to $600 to have this done. It could help uncover even more opportunities for improving weatherization.
Air sealing
Your basement presents several important opportunities to prevent air leaks and costly energy losses. Some areas that an energy professional will focus on are:
- Sealing gaps around electrical work and plumbing with foam or caulk
- Adding weatherstripping to bulkheads or walk-out doors
- Sealing rim joists in basements (the structural framing between the top of the foundation and the floor above) in preparation for insulation
- Sealing around the perimeters of basement windows with caulk or spray foam
- Replacing single-pane basement windows with at least double-pane models
Insulation
Insulation slows down heat transfer through walls, roofs, and floors—and has its place in basements, too. For unheated basements or those not used as living spaces, insulating the rim joist is a common target. In addition, insulating the ceiling (between the joists of the floor above) or adding spray foam insulation to the interior walls can greatly reduce heat loss in the winter and heat gain in the summer.
Most professionals recommend air sealing before insulating, because insulation can block access to places that need to be air-sealed. Insulation is not a substitute for air sealing. Talk with your energy assessor to determine the best approach for your situation.
