Three essential elements of an energy-efficient home are airtightness (achieved through draftproofing, also known as air sealing), insulation, and sufficient ventilation. Combine all three, you get a comfortable, low-energy, lower carbon home with excellent indoor air quality year-round and lower heating and cooling bills. Additional benefits include reduced drafts, noise, and moisture problems.

A tight air barrier from careful draftproofing and ample insulation are critical parts of your home’s building envelope. Ample insulation slows down the transfer of heat and cold between the inside and outside, keeping your home warm in the winter months and cool in the summer. Draftproof first, add ample insulation and then ensure adequate ventilation.

A cross-section of home insulation, with labels for the exterior siding, drywall, insulation, and air barrier.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.