Sealing up unwanted draughts is an inexpensive way of saving small to moderate amounts of energy by improving thermal insulation. Draught-free rooms and buildings are more comfortable at lower temperatures, so you can even turn down the thermostat, which also saves on energy bills.

Draught-proofing the building starts by checking window frames, doors, keyholes, letterboxes as well as gaps and cracks caused by damage, such as movement in the floor or walls. Heat escapes through these gaps and cold air gets in. Most measures to block or repair gaps are inexpensive, and depend on the size of the building and general condition of the property (see 'read mode' for simulation).

Common draught-proofing solutions include installing brush strips, rubber blades or other door-sealing solutions, injecting polymer foam into gaps, and using silicone mastic sealants, window insulating film, sleeves or covers for letterboxes, rain deflectors, and other sealing solutions.

Tip

You can carry out a survey of your building to identify where draughts occur, and find a solution for each. If you don't live or work in the building, talk to the people who do. Keep in mind that draught-proofing products might require replacing after some time, so perform regular maintenance and renovation, as needed. Also ensure that the building still has enough fresh air and ventilation points (especially in the presence of ovens, fuel-fired cooking equipment, hot water boilers, etc.).