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.
Looking for replacement windows in South Glamorgan? We organise the whole job, bringing in the trades it needs under one agreement, and you have a single contact. We cover Cardiff, Barry, Penarth and Llantwit Major, along with villages and suburbs nearby. The rules in Wales decide what consents are needed, and our guide range of £4,100–£8,300 including VAT gives you a realistic starting point for a budget.
- Guide price
- £4,100–£8,300 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Planning rules
- Wales
- Price level
- About 8% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
Replacement windows prices in South Glamorgan
What will replacement windows cost in South Glamorgan? Our guide range is £4,100–£8,300 including VAT. That figure is adjusted for Wales, about 8% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in South Glamorgan |
|---|---|---|
| One to three windows | Replacing a few problem windows, such as a bay or a rotten kitchen window, in uPVC. | £650–£2,800 |
| Whole house in uPVC | Eight to ten standard uPVC casement windows on a typical 3-bed semi, fitted and finished. | £4,100–£6,900 |
| Whole house in aluminium or flush sash | Premium frames, colours or period styles across a typical 3-bed home. | £6,900–£13,000 |
What moves the price up or down:
- 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’s included?
- Measured survey of every opening, with sizes checked before manufacture
- Made-to-measure frames in your chosen material, colour and style
- Double-glazed units as standard, with triple glazing as an option
- Fixings, packers, foam and weather seals to suit your wall type
- Trickle vents, escape hinges and safety glass where regulations require
- Building regulations sign-off arranged and paperwork handed over
Homes in South Glamorgan
Cardiff has large areas of bay-fronted Victorian and Edwardian terraces in districts such as Roath, Canton and Cathays, plus interwar suburbs, post-war estates and modern flats around Cardiff Bay. Penarth has Victorian villas, Barry mixes terraces with newer estates, and Vale of Glamorgan villages are often built of local limestone.
Terraces commonly suit loft conversions, side-return and rear extensions, and bay window renewal. Suburban semis take side extensions and driveways, and stone village homes need lime-based repairs.
Mild but wet, with coastal exposure along the Severn estuary and Bristol Channel affecting render, roofline and windows.
Planning and building rules in South Glamorgan
Planning law differs across the UK. For a home in South Glamorgan, it is the Wales rules below that count, and we check them with the council ahead of any quote.
In Wales, replacing windows and doors on a house usually needs no planning permission if the new ones are similar in appearance. Listed buildings, flats and some conservation areas are controlled, so the council should be asked first.
Building Regulations in Wales apply to replacement windows and doors, covering energy performance, ventilation and escape routes. A registered competent person can self-certify the work, or building control inspects it.
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?
We look at the job
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
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for replacement windows.
Plan and prepare
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.
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.
What you can expect from us
Frequently asked questions
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.
Do I need planning permission in South Glamorgan?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. South Glamorgan is in Wales, so Wales's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address 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.
Is triple glazing worth paying extra for?
Triple glazing adds a third pane of glass, which cuts heat loss and outside noise further than standard double glazing. It typically adds around a third to the cost of the glass units and makes opening sashes heavier. It makes most sense on cold or noisy elevations, or in homes being upgraded to a high energy standard. For many houses, modern double glazing with a warm edge spacer gives most of the benefit for less money.
How much will replacement windows cost in South Glamorgan?
As a guide, expect to pay £4,100–£8,300 including VAT for replacement windows in South Glamorgan. That range is adjusted for Wales, which runs about 8% 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.
Towns in South Glamorgan
Looking for replacement windows somewhere in South Glamorgan? Start with the towns below; each links to a page with pricing for your region and coverage details.