Drafty window? Sealed from $2.

Wet the back of your hand and move it slowly round the frame, the sill and the catch – moving air feels noticeably colder on damp skin. A strip of tissue held near the edges works too, since it flutters where there's a draught. Don't use a naked flame near curtains and moving air; it's the version you'll see recommended most often and it's the one worth skipping.

It does, particularly on single glazing – it traps a layer of still air against the glass, which is much of what double glazing does. It needs a clean dry frame, and a hairdryer on a low setting to pull it taut. The drawbacks are that you can't open the window until spring and it's visible up close, so it suits rooms you don't sit in more than a living room.

The reusable putty‑type strips peel away cleanly and can be lifted at the end of the season. Film kits use double‑sided tape, which usually comes off with gentle heat but can leave a little residue. Adhesive foam strip is the one to be careful with on painted wood. If you rent, stick to the removable options and ask before anything permanent.

It can, and this is worth taking seriously. Homes need air movement to carry moisture out, so if you close every gap while also drying laundry indoors and running no extractor fan, you may trade a draught for damp and mould. Keep trickle vents open, run extractors in the kitchen and bathroom, and air rooms briefly each day. Seal the draughts, not the ventilation.

When the frame is rotten or has moved, when the glass is cracked or a sealed unit has misted up inside, or when a window won't close or lock properly. Those are jobs for a professional. If the frame is sound and the problem is worn seals and gaps, sealing is the sensible first step.