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.
If you have replacement windows on your list for a property in Castlereagh, we can help from the first measurements to the final clean-up. For a typical home, plan for 1–2 days on site for a typical house, though larger or more complex jobs take longer. We cover postcodes BT2, BT4, BT5 and BT6 and nearby Belfast, Newtownabbey and Lisburn, and every quote we send is fixed for the scope described in it.
- Guide price
- £3,900–£7,700 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- BT2, BT4, BT5, BT6 and BT7
- Planning rules
- Northern Ireland
- Local area
- Belfast
- Survey
- Free, with a written quote
Replacement windows prices in Castlereagh
What should you budget for replacement windows in Castlereagh? Use the figures below as a starting point. Prices in Northern Ireland sit about 14% below the national guide, so the range here is £3,900–£7,700 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Castlereagh |
|---|---|---|
| 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 |
Expect these to shape the final quote:
- Number and size of windows, including bays and large picture windows
- Frame material, colour and finish, inside and out
- Window style, such as sash, flush sash or tilt-and-turn
- Upper-floor access, scaffolding and the condition of reveals and sills
What does the job include in Castlereagh?
- Made-to-measure frames in your chosen material, colour and style
- Double-glazed units as standard, with triple glazing as an option
- Careful removal and disposal of the old frames and glass
- 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
Homes in County Down
County Down takes in suburbs of Belfast, Bangor and Holywood with Victorian and Edwardian villas, and Newry, Downpatrick and Banbridge with older town centres and newer estates. Mourne granite appears in buildings around the mountains, and detached rural homes and bungalows are common across the county, often rendered or pebbledashed.
Villas and semis suit kitchen extensions, loft conversions and garden landscaping. Rural detached homes commonly take extensions and driveways, and rendered houses often need re-rendering, roofline renewal and window replacement.
Knowing the typical building types in County Down helps, but a survey of your own home in Castlereagh is what decides the right approach to replacement windows.
Permissions for replacement windows in Castlereagh
As Castlereagh is in Northern Ireland, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
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.
What happens after you get in touch?
Free site survey
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.
Price and scope agreed
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Getting ready
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
Finish and handover
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.
How we work
Common questions
Do I need planning permission for new windows?
Planning permission is not usually needed to replace windows with similar ones, but it depends on the size and style of the change, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. Listed buildings normally need consent for any change, and some conservation areas restrict uPVC or new styles. Flats may also need the building owner's approval. We check the position for your property before quoting.
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.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
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.
Do you cover Belfast, Newtownabbey and Lisburn?
Yes. As well as Castlereagh, we cover Belfast, Newtownabbey and Lisburn and the rest of County Down. 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.
Also covering areas around Castlereagh
Coverage for Castlereagh spans BT2, BT4, BT5 and BT6. Close by, Belfast, Newtownabbey and Lisburn are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.

