Double Glazing UK · FENSA & CERTASS Registered Installers
Replace your windows with a vetted, FENSA or CERTASS registered installer. A single uPVC window starts from £450 supplied and fitted, with A-rated glass, a Building Regulations certificate and aluminium and heritage options available. Compare itemised quotes before you book.
Double Glazing for Every Home
From a single replacement window to a whole-house uPVC reglaze or premium aluminium and heritage frames — vetted, FENSA or CERTASS registered installers for every job.
A single replacement uPVC window, supplied and fitted with A-rated glass. The unit cost falls when you do several at once. Style, size and glass spec set the price.
Get quotes →A full reglaze of a typical semi-detached home in uPVC — the most popular choice. Usually one to two days on site and the best value per window across the property.
Get quotes →Slim aluminium or heritage and timber-effect frames for contemporary or period homes. Often made to measure with longer lead times, and the premium choice for looks and sightlines.
Get quotes →Double Glazing Cost Drivers
| Cost driver | Typical effect | When it applies |
|---|---|---|
| Number of windows | Main price factor | More openings mean more units and fitting time — but a lower unit cost |
| Frame material | +£100 – £400/window | Aluminium and timber cost more than uPVC for slimmer sightlines |
| Glass spec | +£50 – £250/window | A-rated, triple, acoustic or toughened glass adds to the unit price |
| Style & shape | +£100 – £500 | Bay, sash, arched and shaped windows cost more than casements |
| Access & making good | Varies | Upper floors, scaffolding and reveals or plastering after fitting |
A single uPVC window usually sits inside the £450–£900 range, and a whole-house uPVC reglaze of a semi £4,500–£8,500. London and the South East run higher. A full double glazing cost breakdown is in our cost guide.
3 Steps to a FENSA-Registered Window Quote
Tell us about your windows
60-second form. The number of windows, the frame material you want, whether it is a full reglaze and your postcode. No phone, no jargon.
Get matched to installers
Up to 3 vetted, FENSA or CERTASS registered installers near you. We pre-screen on registration and reviews.
Compare & book
Itemised quotes within 24 hours. Compare the frame material, glass spec, guarantee and FENSA certificate before you book.
Get Accurate Quotes From Window Installers
The price depends on the number of windows, the frame material, the glass spec and the style. The most accurate quotes come from a quick survey — get up to 3 vetted, FENSA or CERTASS registered installers to measure and quote, completely free.
A-Rated Glass & Frame Materials (2026)
The glass and frame you choose drive both the look and the energy performance. Here is what to weigh up.
🪟 A-rated energy glass
A-rated double glazing uses a low-emissivity coating, an argon-filled gap and a warm-edge spacer to cut heat loss. Triple glazing goes further and helps with noise on busy roads.
🧱 uPVC — best value
uPVC is the most cost-effective and well-insulated choice, with low maintenance and a wide range of styles and colours. It suits the majority of UK homes.
🏙️ Aluminium — slim & modern
Aluminium frames are strong and slim, giving more glass and a contemporary look. They cost more but are ideal for large openings and modern extensions.
🏛️ Heritage & timber
Timber and heritage-style frames suit period and conservation-area properties where appearance matters, and modern timber-effect options keep maintenance low.
FENSA Certificates & Conservation Areas
Replacement windows are covered by Building Regulations, and your registered installer self-certifies the work.
📜 FENSA / CERTASS certificate
A FENSA or CERTASS registered installer self-certifies the work against Building Regulations and you receive a certificate. This matters for your warranty and when you come to sell the property.
🏠 No planning permission (usually)
Replacing windows is permitted development in almost all cases. Your installer handles Building Regulations compliance through their registration.
🏛️ Conservation areas & listed buildings
Conservation areas and listed buildings may restrict changing the frame material or style and can need consent. Your installer will check before any work starts.
💰 Resale value
Energy-efficient, certified windows improve the EPC rating and reassure buyers — a FENSA certificate is one of the documents a conveyancer asks for on sale.
Double Glazing FAQs
Double Glazing Installers by Town
Vetted, FENSA or CERTASS registered double glazing installers across UK towns:
Double Glazing Guides & Costs
Planning new windows? These guides explain costs and your options.
Double Glazing Cost (2026)
A full breakdown of window costs by frame material, glass spec and project size, with money-saving tips.
Read more →Sash Window Cost (2026)
Costs for repairing or replacing traditional and modern sash windows, including heritage options.
Read more →Local Trades Near You
Find vetted local tradespeople for windows, doors and home-improvement projects across the UK.
Read more →Looking for local quotes? Find vetted trades in your town →