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.
Our guide for replacement windows in Northern Ireland comes to £3,900–£7,700 with VAT added, and that range applies across County Down, including Bangor, County Down, Castlereagh, Newtownards and Newry. Your own price depends on the size of the job, the specification and how easy it is to work on the site. We survey for free, check any consents needed under the rules in Northern Ireland, and then put the price in writing.
- Guide price
- £3,900–£7,700 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Planning rules
- Northern Ireland
- Price level
- About 14% below the national guide
- Towns listed
- 5
- Survey
- Free, with a written quote
Replacement windows prices in County Down
No two jobs cost exactly the same, but the ranges below give a fair picture of replacement windows in County Down. Pricing for Northern Ireland runs about 14% below the national guide, and the overall guide is £3,900–£7,700 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in County Down |
|---|---|---|
| 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 |
Your price depends mostly on:
- Number and size of windows, including bays and large picture windows
- 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
Scope of the work
- Double-glazed units as standard, with triple glazing as an option
- 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
Housing across 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.
Coastal areas such as the Ards Peninsula face salt and wind, and the Mournes bring heavier rain and colder conditions.
Do you need permission in County Down?
The notes below cover Northern Ireland, which is where County Down 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.
The four stages
Free site survey
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for replacement windows, and photograph or measure anything the quote needs to reflect.
Quote in writing
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
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.
How we work
Questions about replacement windows in County Down
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.
How much will replacement windows cost in County Down?
As a guide, expect to pay £3,900–£7,700 including VAT for replacement windows in County Down. That range is adjusted for Northern Ireland, which runs about 14% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Will new windows stop condensation?
New windows reduce condensation on the glass because the inner pane stays warmer, but they do not remove the moisture in the air that causes it. Modern frames are also more airtight, so ventilation matters more after replacement. We fit trickle vents where regulations require them, and we suggest using extractor fans and opening windows regularly. If walls are damp or mouldy, it is worth looking at ventilation and heating at the same time.
Should I choose uPVC or aluminium windows?
uPVC windows are the lower-cost choice, insulate well and need only occasional cleaning, which suits most houses. Aluminium windows have slimmer frames that let in more light and suit modern homes or large openings, but they cost more. Both come in a wide range of colours and finishes. We usually recommend matching the style and proportions of your home's original windows, especially on period properties.
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.
Towns in County Down
We offer replacement windows in each of the towns below, all within County Down. Select yours for guide prices, postcodes covered and nearby places.

