How Draughty Front Doors Cost You Money
Written by Cornwall Composite DoorsReviewed by Cornwall Composite Doors installersLast updated July 20266 minute read
Short answer
A draughty front door lets warm air escape and cold air in continuously, meaning your heating runs longer or hotter to compensate. Over a heating season this adds to your bills, and unlike a one-off cost, it repeats every year the draught remains unaddressed.
It's easy to ignore a slightly draughty front door, especially if the gap seems small. But draughts tend to worsen gradually, and the ongoing cost adds up more than most people expect.
How draughts actually increase your bills
A draught creates continuous air exchange between inside and outside, cooling the hallway and nearby rooms faster than the walls or windows would alone. Your heating system then has to run for longer, or at a higher setting, to maintain the same comfortable temperature — a cost that repeats every day the draught exists.
Common causes of a draughty front door
Draughts usually come from a specific, identifiable source rather than the door as a whole failing.
- A worn or compressed weatherstrip that no longer seals fully
- A warped timber panel or frame no longer sitting flush
- A letterbox without an internal brush seal
- A worn cylinder or multi-point lock not pulling the door tight
- Gaps around the frame from a poor original installation
Want a quick price?
Free survey, no salesman, no obligation.
Why the problem tends to get worse
Seals degrade gradually with UV exposure and repeated compression, and any warping in timber or poorly fitted frames worsens with each wet season. A draught that's barely noticeable one winter can become obvious within a few years if the underlying cause isn't addressed, rather than staying static.
Repair or replace?
If the draught is due to a worn seal or a loose hinge on an otherwise sound composite door, a repair is usually sensible and inexpensive. If the frame itself has warped, the door has swollen, or the doorset is old and was never particularly efficient, replacement is likely to be the more cost-effective long-term option.
Checking your own door
A simple check is to hold a hand near the edges of the closed door on a windy day and feel for movement, or look for daylight around the frame from inside with the lights off. Both are quick, free ways to identify whether a draught exists before deciding on repair or replacement.
Frequently asked questions
How much does a draughty door really cost per year?
It varies too much by property and heating system to give a single reliable figure, and any specific number should be treated with caution. What's certain is that an ongoing draught increases heating demand every day it remains unaddressed.
Can I fix a draughty composite door without replacing it?
Often yes — worn seals, loose hinges, and misaligned locking keeps can usually be adjusted or replaced without needing a full new doorset, provided the frame itself hasn't warped or been damaged.
Is a draught around the letterbox worth fixing?
Yes, letterboxes are a common and easily overlooked draught source. Fitting or replacing an internal brush seal is a low-cost fix that can noticeably reduce cold air entering the hallway.
Explore next
More energy efficiency advice
- Do Composite Doors Keep Heat In?Composite doors are built with a solid insulated core and multi-point locking that compresses a draught seal, so they hold heat in far better than most old front doors.
- How Composite Doors Reduce Energy BillsA composite door reduces energy bills by cutting heat loss through the panel and sealing draughts around the frame, easing the load on your heating system.
- Winter-Proof Your Home with a Composite DoorA composite door with a good U-value and full-perimeter seal is one of the more practical ways to prepare your home for a Cornish winter.
