Spotting a draughty window
A draught is air moving through or around the window, not just a cold pane. The quickest check is to run the back of your hand around the opening edge, the frame-to-wall junction and any trickle vent on a windy day, or hold a thin flame near the seals and watch it pull. Daylight at the corners of a closed sash is another clear sign.
Most draughts trace back to a few places. Knowing which one it is decides whether you adjust, reseal or replace.
- Worn or compressed gaskets and weatherseals.
- Hinges, friction stays or locking points out of adjustment, so the sash does not pull in evenly.
- Perimeter gaps where the frame meets the wall, often hidden behind trim.
- Trickle vents stuck open or fitted without a baffle.
Repair, reseal or replace
Start with the cheapest fix. Gaskets and weatherseals are replaceable, and hinges and locking points can usually be adjusted so the sash compresses the seal evenly again. If the perimeter seal has failed, raking out and resealing the frame-to-wall joint often solves it without touching the window.
Replacement is the right call when frames are single glazed, thermally poor, or past the point where new seals hold. At that stage the draught is a symptom of an old specification, and a modern aluminium casement or tilt and turn route with thermally broken frames and multi-line gaskets fixes the draught and the heat loss together.
What a good replacement specification fixes
On a replacement, the parts that stop draughts are the gasket lines, the hardware that pulls the sash in, the threshold detail and the perimeter sealing on install. The parts that stop the cold are the thermal break and the glazing make-up, quoted as a whole-unit U-value. Specify both, because a tight window that still loses heat through the frame has only solved half the problem. The trade note on low-U aluminium routes covers what to send at quote.
Ventilation still has to be planned. Background ventilation is a building regulations requirement, so trickle vents or an equivalent are specified deliberately rather than removed to chase a draught.
VitrineAlu supplies the aluminium to the trade. Installers and builders can send sizes and drawings for a trade quote. For your own home, request a local installer referral and they handle the fit.