Identifying the specific leakage areas requires a little detective work. For optimal results, hire an air sealing contractor or professional energy advisor. However, you can also do it yourself, as described below.

Make yourself a leak detector - all you need are burning incense sticks. Hold two or three together for more smoke and easier detection. Powerful leaks will cause the smoke to dissipate and the tips of the incense to glow. Slower leaks will cause the smoke to trail away or move toward the leak.

On a cold day, check for drafts in all suspected areas. It is easier to locate air leaks on a windy day. Check for possible leaks on the interior walls and features, such as electrical outlets and switches, because there may be a direct route through partition walls or along floor joists to the outside that should be sealed.

You can perform a rudimentary fan test by closing all windows and doors and turning on all the exhaust appliances in the house, i.e. bathroom and kitchen fans, clothes dryers (on cool cycle) and any portable fan placed in a window (if you can seal around it). However, before starting, turn off any fuel-fired space and water heaters to prevent backdrafting. You can now go around the house with your leak detector and identify and mark the air leakage locations that should be sealed.