Low-emittance - or Low-E - windows are an increasingly common way to control temperature within the building envelope. Traditionally, windows were accepted as being “energy losers” - they lacked the insulation found in the rest of the building frame, so they were prime locations for heat to escape in winter or for cool air to escape in summer (either being conducted through the glass or slipping through cracks in the window frame).

Along with weatherstripping, caulking is one of two essential techniques for sealing air leaks in your home. It is ideal for sealing gaps that don’t open and shut - for instance, where your fireplace or an air vent is built into the wall. It works best where cracks or gaps are less than ¼ inch wide. Caulking consists of applying a thick substance called caulk directly over gaps. The substance soon dries, forming an airtight barrier between the inside and outside. As an added bonus, caulking will also help prevent moisture from seeping into your home, which will help keep mold out, and it can be an effective barrier against insects.