Replacement windows are new frames and sealed double- or triple-glazed units fitted into your existing openings after the old windows are taken out, improving warmth, security and noise reduction while meeting current building regulations.
In Belfast, as anywhere in County Antrim, the price of replacement windows is driven mainly by size, materials and access. Across Northern Ireland our guide sits at £3,900–£7,700 with VAT, but restricted parking, a narrow side passage or extra preparation can move the figure either way. That is why every price we give follows a visit to the house.
- Guide price
- £3,900–£7,700 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- BT1, BT2, BT6, BT7 and BT12
- Planning rules
- Northern Ireland
- Local area
- County Antrim
- Survey
- Free, with a written quote
How much do replacement windows cost in Belfast?
Here is how the guide price for replacement windows breaks down in Belfast. We start from national figures and adjust for Northern Ireland, which comes out about 14% below the national guide. The resulting range, VAT included, is £3,900–£7,700, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Belfast |
|---|---|---|
| One to three windows | Replacing a few problem windows, such as a bay or a rotten kitchen window, in uPVC. | £600–£2,600 |
| Whole house in uPVC | Eight to ten standard uPVC casement windows on a typical 3-bed semi, fitted and finished. | £3,900–£6,400 |
| Whole house in aluminium or flush sash | Premium frames, colours or period styles across a typical 3-bed home. | £6,400–£12,000 |
What moves the price up or down:
- Frame material, colour and finish, inside and out
- Glazing type: double, triple, acoustic, obscure or toughened
- Window style, such as sash, flush sash or tilt-and-turn
- Upper-floor access, scaffolding and the condition of reveals and sills
What’s included?
- Measured survey of every opening, with sizes checked before manufacture
- Careful removal and disposal of the old frames and glass
- Fixings, packers, foam and weather seals to suit your wall type
- New internal trims, external cills and neat sealant finishing
- Trickle vents, escape hinges and safety glass where regulations require
- Building regulations sign-off arranged and paperwork handed over
Building in Belfast
Belfast has long rows of red-brick Victorian terraces, Edwardian villas in the north and south of the city and large post-war estates, while towns such as Ballymena, Antrim, Larne and Carrickfergus mix terraces, semis and newer developments. Dark basalt appears in older rural buildings, and pebbledash or roughcast is a very common finish.
Terraces suit loft conversions and rear extensions, and many need window and roof renewal. Pebbledashed homes commonly need re-rendering, and detached rural houses often take extensions, porches and driveways.
For replacement windows in Belfast, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Permissions for replacement windows in Belfast
The notes below cover Northern Ireland, which is where Belfast sits. Rules change and every property is different, so we speak to the council before pricing your job.
In Northern Ireland, like-for-like replacement windows and doors on a house rarely need planning permission. Listed buildings and conservation areas are the main exceptions, so check with the council before changing style or material.
The Building Regulations (Northern Ireland) apply to replacement windows, so the work needs building control approval or sign-off through an approved competent person route.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
A free survey comes first. It gives us what we need to price replacement windows properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Booking the work
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Why homeowners choose us
Common questions
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
How do I look after new uPVC or aluminium windows?
Caring for new windows is simple: wash frames and glass with warm soapy water a few times a year, avoiding abrasive cleaners and solvents. Clear the drainage slots at the bottom of the frame so rainwater can escape, and put a drop of light oil on hinges and locking points once a year. Check seals and the sealant around the outside every few years, and replace any that have cracked or shrunk.
How long does it take to fit windows in a house?
Fitting replacement windows in a typical 3-bed house usually takes one to two days on site. We take out and fit one window at a time, so each room is weathertight again within an hour or two. Bays, sash windows and homes needing scaffolding take longer. Manufacture comes first: made-to-measure frames typically take a few weeks to arrive after the survey and your order are confirmed.
Do you cover Castlereagh, Newtownabbey and Lisburn?
Yes. As well as Belfast, we cover Castlereagh, Newtownabbey and Lisburn and the rest of County Antrim. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
How much do replacement windows cost?
Replacement windows for a typical 3-bed semi cost £3,900–£7,700, depending on the number of windows, frame material and glazing. A single standard uPVC casement usually works out at roughly £500–£950 fitted, while aluminium, flush sash and sliding sash styles cost more. Bays, large panes and upstairs access add to the price. We measure every opening during the survey and give you a fixed price for the agreed specification.
Also covering areas around Belfast
Addresses in BT1, BT2, BT6 and BT7 are all covered for Belfast, along with Castlereagh, Newtownabbey and Lisburn close by. Give us your postcode when you get in touch and we will confirm the details.

