Do not seal every gap that feels cool. First decide whether the moving air is an unwanted draught, useful ventilation or a sign that something needs repair. Walk through the home with three headings on a sheet of paper and record each window, external door and vent. Only the draught column is a candidate for draught proofing. Leave designed ventilation open and get persistent damage, damp or appliance related concerns checked properly.
Why a draught and ventilation are not the same
A draught is uncontrolled air entering through an accidental gap. Ventilation is the planned movement of fresh air through features such as trickle vents, wall vents and extractor fans. They can both feel cool, but they do different jobs.
The Energy Saving Trust draught proofing guidance warns against blocking extractors, airbricks, wall vents and trickle vents. Fixed ventilation may also be essential around some fires, flues and gas appliances, so leave it alone and seek qualified advice if you are unsure.
Make three columns before you inspect a room
Label the page draught, ventilation and repair. This small distinction stops one cold spot becoming an afternoon of buying seals before you know what is wrong.
- Draught: an unwanted gap around an opening, frame or letterbox
- Ventilation: a designed route that supplies or removes air
- Repair: damage, repeated moisture or movement that needs more than a removable strip
Start with windows and external doors
Choose a breezy day if possible and move slowly around the frame. Look for visible light, a loose seal, rattling or a curtain that moves when the window is shut. Listen for a whistle and check whether the opening closes evenly. Do not use a candle or other flame to test the airflow.
Write down the exact location rather than simply noting that the room feels cold. A gap at the opening edge may need a different solution from cracked sealant around a fixed frame. If the frame is damaged, difficult to close or showing signs of water entry, put it in the repair column.
Which openings should you leave alone?
Do not cover a trickle vent because it feels cool on one day. Do not block an extractor, wall vent or airbrick, and do not fill a gap that appears to be part of a fire, flue or appliance installation. The Energy Saving Trust ventilation advice says trickle vents should generally stay open and extractors should be used when cooking, bathing or showering.
If a vent is noisy, dirty or appears ineffective, record that as a maintenance question. Clean only the parts covered by the manufacturer's instructions. A blocked or broken system needs the correct repair, not a piece of fabric or tape placed over it.
Let moisture change your diagnosis
Repeated condensation, a musty smell or mould around a window is not a reason to seal the room more tightly. It may point to insufficient ventilation, a cold surface, a leak or another building problem. The Energy Saving Trust has separate guidance on damp and condensation because the right action depends on the cause.
Record when and where moisture appears. Note whether it follows cooking, washing or indoor laundry, and whether an extractor is working. Treat visible mould promptly using appropriate guidance, and report recurring damp or building defects to the responsible landlord, factor or professional rather than guessing at a permanent fix.
Is every cold spot an air leak?
No. A cold window surface, bare floor, outside wall or poorly placed chair can make part of a room feel uncomfortable without a strong flow of air. Move the chair, rug or thermometer for a day and compare the result before buying anything.
If warm weather is still the immediate problem, use our guide to cool a hot room without air conditioning. Keep that summer routine separate from the question of what the home needs when temperatures fall.
Turn the notes into three next steps
Finish the walk by choosing one action from each useful category:
- Do now: clear clutter from a designed vent, check a removable door draught excluder is the right size, or follow the instructions for cleaning an extractor filter.
- Book: arrange appropriate help for a damaged frame, repeated water entry, persistent mould or anything connected with a flue, fire or fixed appliance.
- Watch: photograph and date a minor cold spot or one off patch of condensation, then check it again when the weather changes.
Keep the list short. A room by room record is more useful than sealing several places and then trying to work out why the air feels stale.
Add comfort after the diagnosis
Once you know the window or door closes properly and useful ventilation is clear, fabric can add another layer of comfort and privacy. Measure the width and drop carefully, check where a radiator or vent sits, and read our curtain guide for different rooms before choosing a header or lining.
If a heavier treatment genuinely suits the room, browse thermal and blackout curtains after measuring. Curtains can improve comfort around a sound window, but they should not be presented as a repair for damage, damp or blocked ventilation.
For today, inspect one room and give every cold spot one of the three labels. That is enough to stop an autumn comfort job turning into unnecessary work, while protecting the airflow the home still needs.
