The first step to reducing drafts is to identify the air leakage areas throughout your home. Although you might feel drafts and see air leakage areas around windows and doors on the main floor, in most homes, the most significant air leaks are often found in the attic/top floor and basement/lowest floor and are often hidden. This is due to the stack effect: In a heated home, less dense warm air rises and expands, creating a higher-pressure area near the top of the house. As cold air pushes into the lower portions of your home it forces the lighter, warm air up and out through leaks at the top.

In general, the priorities for air sealing are:

  1. Large holes regardless of location (plumbing or electrical penetrations, ductwork through unconditioned spaces, large gaps under doors, masonry chimney chaseways)
  2. Smaller holes on top floor ceiling/attic (pot lights, ceiling penetrations around fixtures, attic hatch, attic knee walls, service shafts, etc.)
  3. Smaller holes on the bottom floor (hose bib penetrations, cracks on exterior and foundation walls, basement doors, electrical boxes, gas lines or oil fill pipes that go through exterior walls, etc)
  4. Smaller holes on main floors (windows, doors, top and bottom of baseboards, fireplace dampers, electrical outlets, switches)

For a more in depth air sealing analysis of your home, you can have an EnerGuide Home Evaluation performed on your home to find any obvious or hidden drafts that need sealing. A program-qualified energy advisor will come to your home, perform a blower door fan test/depressurization test and look for air leaks. The advisor will also use the data from the depressurization test and calculate the air leakage rate for your home. The Renovation Upgrade Report provided by the energy advisor will include a prioritized list of draftproofing measures for your home.

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