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 live in Cardiff and are weighing up replacement windows, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across CF10, CF11 and CF24, and a typical project of this kind in Wales lands somewhere in the £4,100–£8,300 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £4,100–£8,300 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- CF10, CF11 and CF24
- Planning rules
- Wales
- Local area
- South Glamorgan
- Survey
- Free, with a written quote
Replacement windows prices in Cardiff
In Cardiff, guide figures for replacement windows sit at £4,100–£8,300, VAT included. We set them using rates for Wales, currently about 8% below the national guide. The table shows what pushes a project towards either end of the range; your own price is set after a free survey.
| Type of job | What it usually involves | Guide in Cardiff |
|---|---|---|
| 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 |
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
Scope of the work
- 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
- Careful removal and disposal of the old frames and glass
- New internal trims, external cills and neat sealant finishing
- Building regulations sign-off arranged and paperwork handed over
What are homes like around Cardiff?
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.
That variety is why a guide price for replacement windows in Cardiff is only a starting point; the survey shows what your particular property needs.
Planning and building rules in Cardiff
Homes in Cardiff come under the regulations for Wales, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
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.
What happens after you get in touch?
We look at the job
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.
Plan and prepare
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
On site to finish
Our trades complete replacement windows while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Working with SK Home Improvements
Common questions
Do I need planning permission in Cardiff?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Cardiff 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 much will replacement windows cost in Cardiff?
As a guide, expect to pay £4,100–£8,300 including VAT for replacement windows in Cardiff. 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.
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.
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.
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.
Also covering areas around Cardiff
Our coverage in Cardiff includes CF10, CF11 and CF24. We also travel to Penarth, Caerphilly and Barry, so neighbouring addresses are looked after on exactly the same terms as those in town.