Locate the discomfort
Walk around the room in windy weather and note where air movement is uncomfortable. In a British home, a draught around an opening joint is different from an intentional ventilation opening. Record the location and condition before buying sealing products.
Inspect the opening and its function
Check whether the window or door closes properly and whether existing seals are damaged. A worn hinge or distorted frame may need a repair rather than another strip of foam. Read the product instructions and confirm that the proposed material suits the gap.
Keep essential airflow available
Energy Saving Trust emphasises the importance of ventilation when reducing draughts. Do not cover air bricks, extract openings or vents required by appliances. If you are unsure what an opening serves, identify it before changing it. Combustion and ventilation questions need appropriate professional assessment.
Evaluate a small change
Begin with one suitable repair and check comfort, operation and any change in condensation. Keep a record of what was fitted so later maintenance is straightforward. For tenants, agree modifications with the landlord where required. Avoid sealing several rooms at once without understanding the building’s ventilation arrangement.