A cold draught can make a room feel uncomfortable even when the heating is on.
You might notice it when you’re sitting beside a window, walking past the front door or feeling a stream of cold air across the floor on a windy evening. Sometimes there’s an obvious gap. Other times, finding where the cold air is getting in can be surprisingly difficult.
The good news is that draughty windows and doors don’t automatically need replacing.
Many unwanted gaps can be tackled with relatively simple DIY fixes, from self-adhesive draught-proofing strips around opening windows to a brush along the bottom of an external door.
The important part is finding where the draught is actually coming from and choosing the right solution for that particular gap.
This guide explains how to find common draughts around windows and doors, which type of draught-proofing to use and when a simple DIY fix might not be enough.
How to Find Where a Draught Is Coming From
Before buying draught-proofing tape, sealant or a new door excluder, spend a few minutes finding the actual source of the problem.
A cool or windy day is useful because draughts are easier to notice.
Close the windows and external doors and slowly check around:
- the edges of opening windows
- between windows and their frames
- fixed window frames
- sliding sash windows
- the sides and top of external doors
- underneath external doors
- letterboxes
- keyholes
Sometimes you can simply feel moving cold air with your hand.
There can be other clues too. Look for curtains moving when a window is closed, faint whistling sounds, rattling windows or thin lines of daylight around a closed door.
You may also find several small draughts rather than one large gap.
Work around the room methodically and make a note of each problem area before deciding what you need to buy.
Draught or ventilation?
There is an important difference between an unwanted draught and intentional ventilation.
Draught-proofing is about reducing uncontrolled gaps that allow cold air into the home. It isn’t about making a room completely airtight.
Don’t automatically block:
- trickle vents
- air bricks
- ventilation grilles
- extractor systems
- other purpose-made ventilation openings
These features help fresh air move through the home and allow moisture and pollutants to escape.
This is particularly important in kitchens, bathrooms and other areas where moisture can build up.
If you’re unsure whether an opening is an accidental gap or part of the home’s ventilation, leave it alone until you know what it does.
Which Type of Draught-Proofing Do You Need?
Different gaps need different solutions.
Before heading to the DIY shop, identify whether you’re dealing with a moving part of a window or door, a fixed gap, or something more specific such as a letterbox.
| Where you’ve found the draught | A practical solution to consider |
|---|---|
| Around an opening window | Self-adhesive foam or rubber draught strip |
| Fixed gap around a window frame | Flexible sealant |
| Sliding sash window | Brush strip |
| Around the edge of an external door | Foam, rubber, brush or wiper strip |
| Under an external door | Door brush or hinged flap |
| Letterbox | Letterbox brush or flap |
| Keyhole | Purpose-made keyhole cover |
The right product should close the unwanted gap without preventing the window or door from working properly.
If you’re unsure what to buy, start with the exact place where you can feel the cold air rather than buying a general draught-proofing kit and trying to use the same product everywhere.
How to Draught-Proof Windows
Windows are one of the first places worth checking when a room feels draughty.
Older windows can be particularly noticeable, but even relatively modern windows may develop small gaps as seals age or components move over time.
The correct fix depends on whether the draught is coming through an opening section of the window or from a fixed gap around the frame.
1. Draught-Proof Opening Windows
If cold air is getting through the gap between an opening window and its frame, a draught-proofing strip can be a straightforward solution.
Self-adhesive foam strips are inexpensive and easy to find. Rubber seals and other longer-lasting weather strips are alternatives depending on the type of window.
Start by opening the window and cleaning the area where the strip will be attached.
Dust, grease and old adhesive can prevent self-adhesive products from sticking properly, so don’t skip this step.
Allow the surface to dry completely.
Next, look at the size of the gap you’re trying to fill.
This matters more than it might seem.
A strip that’s too thin may not make enough contact when the window closes, leaving the draught largely unchanged.
A strip that’s too thick can become heavily compressed and make the window difficult — or even impossible — to close properly.
Measure the gap where possible and check the manufacturer’s recommended gap size before choosing a product.
Cut the strip neatly to length and apply it gradually rather than removing all the backing at once. Press it firmly into place, particularly around corners.
Once fitted, close and reopen the window several times.
It should still operate normally while the seal closes the unwanted gap when the window is shut.
2. Seal Fixed Gaps Around Window Frames
Not every window draught comes through the opening section.
You may instead find a small fixed crack between the window frame and the surrounding wall or finish.
A suitable flexible sealant may be more appropriate here.
The important word is fixed.
Don’t fill a joint with sealant if that part of the window needs to move.
Before applying anything, remove loose material and clean the area. Follow the instructions for the particular sealant you’re using, including any required drying or curing time.
If a gap is unusually large, continues to grow or appears alongside obvious movement or damage, investigate the underlying problem rather than repeatedly filling it.
3. Draught-Proof Sash Windows
Traditional sliding sash windows need a slightly different approach.
Because sections of the window need to slide past one another, ordinary foam draught-proofing tape may interfere with their movement.
Brush seals are commonly used because the fine bristles can reduce unwanted airflow while still allowing the sash to move.
Straightforward draught-proofing may be manageable yourself, but complicated or valuable traditional windows can be worth having professionally assessed.
The aim should be to improve the window without unnecessarily losing a feature that may still have many years of useful life.
4. What About Old Wooden Windows?
A draughty timber window can easily lead to the assumption that the whole thing needs replacing.
That isn’t always the case.
Older windows may develop gaps after years of movement, wear and repeated painting, but that doesn’t necessarily mean the window itself has reached the end of its life.
Check the condition of:
- the timber
- hinges
- catches
- joints
- glazing
- moving sections
A fundamentally sound window may simply need adjustment, repair and appropriate draught-proofing.
Rotten timber, badly distorted frames or substantial damage are different problems and may require repair rather than another layer of weather strip.
If you live in a listed building or are dealing with historically important windows, check what permissions or specialist advice may be needed before making significant alterations.
How to Draught-Proof an External Door
A front or back door has several potential places for cold air to enter.
Rather than treating the whole door as one problem, close it and check four areas separately:
the edges, the bottom, the letterbox and the keyhole.
You may find that only one or two actually need attention.
5. Seal Gaps Around the Door Frame
If you can feel air entering around the top or sides of a closed external door, weather stripping may help.
Depending on the door, this could be a foam, rubber, brush, compression or wiper-style strip.
As with windows, choosing the correct size matters.
The material needs to close the gap when the door shuts without creating so much resistance that the door becomes difficult to use.
Clean the frame before fitting adhesive products and work around it carefully.
Once finished, open and close the door several times.
Check that:
- the door closes normally
- the latch engages properly
- the lock still operates easily
- the new seal remains in position
A door shouldn’t suddenly need to be slammed because you’ve added draught-proofing.
If it does, check the thickness and position of the seal.
6. Stop Draughts Under an External Door
The bottom of a front or back door can be one of the most noticeable sources of cold air.
If you can see daylight underneath the closed door or clearly feel air moving across the floor, consider a door brush or suitable flap-style draught excluder.
Measure the width of the door before buying one.
When fitting it, position the brush or flap low enough to reduce the gap but not so low that it drags heavily across the floor every time the door opens.
Uneven flooring can make this slightly trickier, so check the full swing of the door before fixing anything permanently.
For an extremely simple option, a fabric draught excluder placed against the inside of the door can also reduce the sensation of cold air.
It won’t create the same permanent seal, but it can be useful in a rented home or while you’re deciding on a longer-term fix.
7. Draught-Proof the Letterbox
Letterboxes are easy to overlook.
If yours opens directly through the front door without an effective internal seal, cold air can pass through it.
An internal letterbox brush or flap can help reduce this.
Measure the existing opening carefully before buying anything rather than assuming every letterbox is a standard size.
After fitting it, check that the letterbox still opens freely and that post can pass through without becoming trapped.
It might seem like a small improvement, but when you’re trying to remove several draughts from one hallway, small gaps can add up.
8. Cover a Draughty Keyhole
Traditional keyholes can provide another small route for outside air.
Purpose-made keyhole covers sit over the opening and move aside when you need to insert the key.
A keyhole cover isn’t going to transform a freezing hallway by itself, but it’s an inexpensive finishing touch once you’ve dealt with the larger gaps around the door.
Cheap Ways to Make Draughty Windows Feel Warmer
Draught-proofing tackles unwanted gaps, but a window can still feel cold even when there isn’t noticeable air leaking through it.
This is particularly true of older or single-glazed windows.
Once you’ve dealt with obvious draughts, there are a few other relatively simple ways to make the area feel more comfortable.
Use Thick Curtains
Curtains create an additional layer between the cold window and the room.
If you’re choosing new ones specifically with warmth in mind, consider heavier or thermally lined curtains and make sure they’re large enough to cover the window properly when closed.
Close them as temperatures drop in the evening and open them during daylight, particularly when sunlight is helping to warm the room.
If a radiator sits directly underneath the window, avoid arranging long curtains in a way that traps most of its heat behind them.
Consider Thermal Blinds
A well-fitted blind can provide another layer at the window.
Thermal blinds are designed with insulation in mind, although even combining an ordinary blind with curtains can make the window area feel less exposed.
Measure carefully before ordering.
Large gaps around a badly fitted blind will reduce the benefit.
Consider Secondary Glazing
If an older window is in reasonable condition but the glazing itself remains noticeably cold, secondary glazing may be worth investigating.
Secondary glazing adds another independent layer on the room side of the existing window.
There are different systems available, ranging from simpler solutions to professionally fitted installations, and suitability will depend on the property and window.
It can be particularly useful where retaining an existing traditional window is important.
However, secondary glazing is a bigger step than applying a strip of draught-proofing tape.
Deal with obvious gaps and maintenance issues first, then decide whether further improvements are worthwhile.
Common Draught-Proofing Mistakes to Avoid
Draught-proofing is relatively straightforward, but a few common mistakes can make it ineffective — or create a new problem.
Using a Strip That’s Too Thick
More isn’t necessarily better.
If foam or rubber strip is much thicker than the gap, the window or door may become difficult to close.
Measure first and choose an appropriate size.
Using a Strip That’s Too Thin
The opposite problem is just as common.
A thin strip might look neat once installed but achieve very little if it doesn’t actually make contact when the window or door closes.
Test the result afterwards rather than assuming the job is finished because the tape is in place.
Sealing Intentional Ventilation
Don’t treat every source of moving air as a draught that needs blocking.
Trickle vents, ventilation grilles and other purpose-designed ventilation have a job to do.
Reducing uncontrolled draughts is useful. Preventing the home from ventilating properly is not.
Using Sealant on Something That Moves
Flexible sealant is useful for appropriate fixed gaps.
It isn’t a replacement for weather stripping around parts of windows and doors that need to open.
Before applying anything, ask one simple question:
Does this joint need to move?
If it does, use a product designed to accommodate that movement.
Covering Up a Problem That Needs Repairing
Draught-proofing products work best when you’re dealing with otherwise functional windows and doors.
A door hanging badly on its hinges, rotten timber, a damaged frame or a window that no longer closes correctly may need repairing first.
Adding more foam tape won’t solve an underlying mechanical problem.
Assuming Old Windows Have to Be Replaced
Older doesn’t automatically mean useless.
Traditional timber windows can sometimes be repaired and improved while retaining their original character.
Start by identifying the actual problem before deciding on replacement.
Can Renters Draught-Proof Windows and Doors?
Renting doesn’t necessarily mean putting up with every cold draught until you move.
There are temporary and low-impact options that may help without making major changes to the property.
A fabric draught excluder placed against the bottom of a door is one of the simplest because it requires no fixing at all.
Some self-adhesive draught-proofing products may also be removable, although it’s worth being careful with painted or delicate surfaces. Adhesive can sometimes leave residue or lift an existing finish.
Curtains and suitable blinds can provide another layer around cold windows where your tenancy and existing fittings allow them.
For anything that requires drilling, permanent sealant or alterations to the window or door itself, check your tenancy agreement and speak to your landlord before making the change.
If the draught is caused by a damaged window, badly fitting external door or another maintenance problem, report it rather than simply covering up the issue yourself.
The same principle applies to other improvements in a rented home: look for changes that solve everyday frustrations without creating unnecessary damage.
If you’re trying to make better use of a rented property without drilling into walls, our guide to 15 No-Drill Storage Ideas for Renters That Won’t Damage Your Walls has plenty of practical storage ideas.
And if you’re trying to make the property feel more like your own without risking your deposit, read 15 Renter-Friendly Decorating Ideas That Make a Rental Feel Like Home.
When Is DIY Draught-Proofing Not Enough?
There comes a point where another roll of foam tape isn’t the answer.
Consider getting appropriate professional advice if:
- a window or door frame is badly warped
- timber is rotten or significantly damaged
- a window won’t close correctly
- hinges, locks or catches are failing
- gaps are unusually large
- a traditional window needs specialist repair
- you’re unsure whether you’re interfering with necessary ventilation
- the issue involves a chimney, flue or combustion appliance
- you’re dealing with a listed building or significant historic features
Draught-proofing should improve an otherwise functional part of the home, not hide a more serious defect.
If several areas of the house remain very cold after obvious draughts have been dealt with, it may also be worth looking beyond the windows and doors.
Insulation, glazing, heating performance and the building itself can all affect how warm a home feels.
Is Draught-Proofing Worth Doing?
If your home has obvious gaps around windows or external doors, draught-proofing can be a relatively inexpensive place to start.
Simple DIY materials can tackle individual problem areas without turning the job into a renovation.
There can also be a financial benefit.
Energy Saving Trust estimates that draught-proofing around windows, floors and doors could save around £55 a year in Great Britain, although the amount will vary depending on the property, its existing condition and how it is heated.
But reducing draughts isn’t only about the energy bill.
Comfort matters too.
A room can feel much more pleasant when you’re no longer sitting beside a stream of cold air from a poorly sealed window or feeling a chilly breeze across the hallway every time the wind picks up.
A Simple Weekend Draught-Proofing Checklist
You don’t need to tackle every window and door in the house at once.
Start with the rooms where you notice the problem most.
1. Find the draughts.
Walk around your home on a cooler or windy day and check windows and external doors for moving air, rattles, visible gaps or daylight.
2. Identify exactly where the air is entering.
Is it an opening window, fixed frame, door edge, letterbox or the bottom of the door?
3. Check whether the gap should actually be there.
Leave intentional ventilation unobstructed.
4. Measure before buying anything.
Check the width, length and depth of the gap so you can choose an appropriate strip, seal or brush.
5. Clean the surface.
Self-adhesive products won’t perform well on dusty or greasy frames.
6. Work on one area at a time.
Fit each product carefully rather than trying to draught-proof the entire house in an afternoon.
7. Test everything afterwards.
Windows and doors should still open, close and lock normally.
8. Recheck the room.
On the next cold or windy day, see whether you can still feel the draught.
These kinds of manageable jobs can make a home work better without turning every improvement into a major project.
For more straightforward projects you can tackle around the home, have a look at 11 Easy DIY Jobs That Make a Home Feel Better Without a Renovation.
Make Your Home Feel Warmer Without a Major Renovation
A draughty home doesn’t automatically need new windows, a new front door or an expensive renovation.
Sometimes the best place to start is much smaller.
Find the unwanted gaps. Work out whether they’re fixed or moving. Choose a product designed for that particular problem, and deal with each draught one at a time.
A strip around a window, a brush underneath a door or a cover over a draughty letterbox might not sound like a dramatic home improvement.
That’s precisely the point.
Small, achievable jobs can make the home you already have more comfortable without requiring a huge budget or weeks of disruption.
And once the obvious draughts are dealt with, you can move on to the next simple improvement.