Britain’s housing stock is old, charming and — let’s be honest — full of holes. Draughty windows are among the worst offenders: the Energy Saving Trust estimates proper draught-proofing can save around £45 a year on energy bills for a typical home, and the comfort difference is immediate. Here’s how to draught proof windows in a UK home, from five-minute fixes to proper long-term solutions.

First, find your draughts properly. On a windy day, hold a lit incense stick or a thin tissue near window edges — anywhere it flutters or the smoke streams sideways, air is getting through. Check the frames, the meeting rails on sash windows, and where the frame meets the wall. You might be surprised how many leaks one room has.

How to Draught Proof Windows in a UK Home: The Quick Wins

Self-adhesive foam strips

The cheapest fix: £5–£10 per window. Clean the frame, stick the compressible foam tape where the opening sash meets the frame, and close the window to compress it. Works well on casement windows; lasts 1–3 years before the adhesive tires. Brilliant as a stopgap or for rented homes.

Brush strips and rubber seals

A step up in durability. Brush-pile strips (the fuzzy stuff) suit sliding sash windows, fitted into the staff beads; rubber compression seals suit casements. A full window kit costs £10–£20 and lasts 5+ years. For sash windows specifically, a proper brush-strip draught-proofing kit — sealing the meeting rails, parting beads and staff beads — transforms the worst offenders in the British housing stock.

Heavy curtains and thermal blinds

Don’t underestimate soft furnishings. Full-length, lined, heavy curtains that sit close to the wall and extend past the frame cut heat loss through windows dramatically — especially at night when curtains are drawn. Thermal Roman blinds with reflective backing do similar work in a neater package. For maximum effect, combine: draught-proof the frame and hang heavy curtains. Either alone helps; together they’re formidable.

Secondary Glazing Film: The Renter’s Secret Weapon

Shrink-film secondary glazing kits (£10–£20 per window) are genius for the price: double-sided tape around the frame, clear film stretched over it, then shrunk taut with a hairdryer. It creates a still-air layer that noticeably cuts both draughts and heat loss, and it’s nearly invisible once fitted. Downsides: you can’t open the window without removing it (fit it on windows you don’t need to open in winter), and it needs redoing each autumn. For single-glazed rentals, it’s the highest-impact cheap fix available.

The Proper Job: Professional Draught-Proofing

For sash windows — the draughtiest common window in Britain — a specialist can rout brush seals into the existing sashes, overhaul the cords, weights and pulleys, and seal everything properly for £200–£400 per window. It’s transformative: rattling, whistling sashes become silent and smooth, and it’s far cheaper than replacement. Listed buildings and conservation areas often require this route rather than new windows, so it’s worth knowing regardless.

For casements, a joiner can replace perished gaskets and adjust ironmongery so sashes close tightly — often the “draught” is just a window that no longer shuts properly. The Energy Saving Trust’s draught-proofing advice covers the whole-house picture, because windows are only part of it: doors, lofts, chimneys and floorboards all leak too.

What About Replacing the Windows?

Draught-proofing costs tens of pounds per window; replacement costs hundreds. If your frames are rotten, single-glazed and beyond economic repair, replacement makes sense — see our guide to double glazing costs. But if the frames are sound and the issue is gaps, draught-proofing delivers most of the comfort benefit for a tenth of the price. Don’t let a salesman tell you draughty sashes “need” replacing when £300 of professional draught-proofing would solve it.

Don’t Forget Ventilation

One caution: houses need some airflow. If you draught-proof aggressively, ensure trickle vents stay open and extractor fans work — otherwise condensation and mould follow. Our guides to stopping window condensation and dealing with damp cover the balance. Seal the uncontrolled draughts, keep the controlled ventilation: that’s the mantra.

Doors, Lofts and Chimneys: The Rest of the House

Windows get the attention, but the average UK home leaks heat from everywhere. Doors: brush strips on the bottom, compression seals around the frame, and a proper letterbox draught excluder (an unsealed letterbox is a wind tunnel). Chimneys: an unused open fireplace is one of the biggest heat-losers in any house — a chimney balloon (£20–£30) or a removable chimney sheep blocks it while staying easy to remove. Loft hatches: insulate and draught-seal them; an unsealed hatch is a hole into a cold void. Floorboards: seal gaps with flexible filler or purpose-made strips, but never block underfloor ventilation airbricks — suspended timber floors need airflow to prevent rot. Do the whole house systematically and the combined saving exceeds £100 a year, with comfort gains no single measure delivers alone.

How Much Difference Does It Really Make?

Let’s set expectations honestly. Draught-proofing won’t transform an uninsulated Victorian terrace into a Passivhaus — but the comfort improvement is disproportionate to the cost. Eliminating cold air streaming across your ankles makes a room feel 2–3 degrees warmer at the same thermostat setting, which means you can turn the heating down a notch without noticing. Combined with the Energy Saving Trust’s estimated £45 annual saving on bills, the payback on £50–£100 of materials is measured in months, not years. It’s the rare home improvement that’s cheap, DIY-friendly, immediately noticeable and genuinely green. Do it before winter, not during it.

Finally, a note on renters’ rights: draught-proofing with removable products (foam strips, secondary-glazing film, heavy curtains) needs no landlord permission and you can take the curtains with you. For bigger fixes like professional sash draught-proofing, it’s worth asking the landlord — it improves their property’s EPC rating and many will agree or even split the cost, especially with energy prices as they are. Put the request in writing and keep it reasonable.

The Takeaway

Start with the incense-stick test, fix the worst windows with brush or foam seals, add heavy curtains, and consider secondary-glazing film for single glazing. Professional sash draught-proofing is the best-value “proper” job in the business. Warm, quiet, cheaper to heat — for the price of a takeaway per window.