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Replace your back door.
uPVC, composite or aluminium back door — supplied, fitted and weather-sealed in half a day.
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Top tips
Hiring a doors, without the regret.
Four moves that separate a smooth job from a nightmare.
Cylinder snap attacks
70% of back-door break-ins involve snapping the Euro cylinder — upgrade to a 3-star Sold Secure cylinder.
Threshold leaks
Rain blowing under the cill is the commonest defect. Look for a deep-rebate cill with under-cill drainage channels.
Hinge bolts missing
Three-bolt hinge-side reinforcement is now standard on quality doors. Cheap units leave the hinge side as the soft target.
Glass without P1A rating
Glazing in a back door should be laminated P1A safety glass — toughened alone shatters into pebbles a burglar can clear.
Costs & timeline
Know what it costs. Know when it ends.
Indicative UK ranges and what affects price.
Cost range
By job type
Inc. VAT · 2026
Source: NMT quotes
Source: NMT quotes
uPVC back door, supplyHalf glazed, white
£350–£700
Composite back door, supplyFoam core, multi-point lock
£700–£1.4k
Aluminium back door, supplySlim sightlines, RAL finish
£1.2k–£2.2k
French back doors, supply (pair)uPVC or aluminium
£900–£2.4k
Installation labourOne day, two fitters
£250–£500
Old door removal & disposaluPVC/composite recyclable
£50–£120
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Quote spread is typically ± 18% — always get 3 quotes.
At a glance
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Doors explained
Your back door takes more punishment than the front — wet boots, garden tools, weather from the prevailing south-west, kids in and out all summer. A typical replacement costs £600–£2,500 fitted in the UK, depending on material and glazing. It's also the most common break-in entry point, so security upgrades pay for themselves at insurance renewal.
What Does the Work Involve?
Replacing a back door usually means swapping the whole frame as well — measuring the brickwork opening, ordering a made-to-measure unit, removing the old door and frame, dressing the threshold, fitting the new frame plumb and square, foaming the perimeter, fitting the slab, hanging it, fitting the multi-point lock, and beading in the glazing. Most installers will also dress the brickwork with silicone and refit any architrave or trim inside.
Typical Costs
| Item | Low (£) | High (£) | Notes |
|---|---|---|---|
| uPVC back door, supply | 350 | 700 | Half glazed, white |
| Composite back door, supply | 700 | 1,400 | Foam core, multi-point lock |
| Aluminium back door, supply | 1,200 | 2,200 | Slim sightlines, RAL finish |
| French back doors, supply (pair) | 900 | 2,400 | uPVC or aluminium |
| Installation labour | 250 | 500 | One day, two fitters |
| Old door removal & disposal | 50 | 120 | uPVC/composite recyclable |
How Long Does It Take?
Single back door replacement is a 4–6 hour job. French or bi-fold style back doors take a full day. Order-to-fit lead times are 2–4 weeks for stock colours, 6–10 weeks for bespoke RAL or unusual sizes.
DIY or Professional?
Professional only if you want the FENSA/Certass certificate for resale and building-regs compliance. A competent DIYer can refit a slab into an existing frame, but full frame replacement requires removing the brick threshold, sealing the cavity, and tying into the DPC — get it wrong and you'll have water tracking into the kitchen.
Choosing the Right Tradesperson
Use a FENSA or Certass registered installer. Ask which brand they fit and request a 10-year warranty in writing. Look for a 3-star Sold Secure cylinder (anti-snap, anti-bump, anti-drill). Confirm the U-value of the complete unit — aim for 1.4 W/m²K or lower to meet Building Regs.
UK Regulations
Approved Document Part L requires replacement external doors to achieve U-value ≤1.4 W/m²K. Part Q security testing (PAS 24) applies to all new-build doors. FENSA or Certass registration self-certifies the install. Listed buildings require consent before any external door change.
Common Problems
- Cylinder snap attacks: 70% of back-door break-ins involve snapping the Euro cylinder — upgrade to a 3-star Sold Secure cylinder.
- Threshold leaks: Rain blowing under the cill is the commonest defect. Look for a deep-rebate cill with under-cill drainage channels.
- Hinge bolts missing: Three-bolt hinge-side reinforcement is now standard on quality doors. Cheap units leave the hinge side as the soft target.
- Glass without P1A rating: Glazing in a back door should be laminated P1A safety glass — toughened alone shatters into pebbles a burglar can clear.
Frequently Asked Questions
Which is the best material for a back door?
Composite is the best all-rounder — secure, warm, weather-resistant, and affordable at £700–£1,400 supply. Aluminium is better if you want slim sightlines and 40+ year life. uPVC is the budget option but the locks tend to wear faster.
Should the back door have glass?
Letting natural light in is the main reason. Use laminated P1A safety glass to keep it secure. Frosted or stippled patterns help privacy.
Can I have a cat flap fitted in a new back door?
Yes — but order with the cat flap pre-fitted at the factory. Retro-cutting a composite or aluminium door voids the warranty and risks the structural foam core.
What lock should I have on my back door?
A multi-point locking system with a 3-star Sold Secure (TS007) Euro cylinder. The 3-star is anti-snap, anti-bump, anti-drill and anti-pick — the lowest spec your insurer will be happy with.
How long should a back door last?
Composite: 30–35 years. Aluminium: 40+. uPVC: 20–25. Locks may need swapping after 15–20 years of daily use.
Do I need planning permission to replace my back door?
No — like-for-like replacement is permitted development under most circumstances, except on listed buildings or in conservation areas where the appearance changes materially.
This guide was written with AI assistance and is intended for general information only. Prices are estimates based on UK averages and may vary by region. Always get at least three quotes and consult a qualified professional before starting any work.
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