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.
Addresses across LL55 fall within our coverage for replacement windows, so if your home is in Caernarfon we can arrange a survey on a day that works for you. We inspect the existing building, discuss materials and layout, and then price the agreed specification in writing. Expect a guide range of £4,100–£8,300 including VAT before that visit.
- Guide price
- £4,100–£8,300 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- LL55
- Planning rules
- Wales
- Local area
- Gwynedd
- Survey
- Free, with a written quote
How much do replacement windows cost in Caernarfon?
These are guide costs, not quotes. For replacement windows in Caernarfon the range is £4,100–£8,300, VAT included, reflecting prices in Wales that are about 8% below the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Caernarfon |
|---|---|---|
| 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 |
Your price depends mostly on:
- 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 does the job include in Caernarfon?
- Measured survey of every opening, with sizes checked before manufacture
- 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
Building in Caernarfon
Slate defines much of Gwynedd, from quarrying villages such as Bethesda and Blaenau Ffestiniog with their stone terraces to slate roofs across the county. Bangor and Caernarfon have Victorian and Georgian streets, Anglesey has stone cottages and bungalows, and resorts such as Pwllheli and Barmouth have Victorian terraces and newer bungalows.
Stone and slate homes need breathable lime render and pointing, and slate roofs often need careful repair rather than replacement. Terraces suit loft conversions, and bungalows commonly take extensions and window upgrades.
Whatever era your Caernarfon home dates from, we plan replacement windows around how it is actually built rather than a one-size-fits-all specification.
Do you need permission in Caernarfon?
Because Caernarfon falls under Wales's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
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.
From survey to handover
Free site survey
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about replacement windows.
Written quote
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
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
Build and hand over
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
Questions about replacement windows in Caernarfon
Which postcodes in Caernarfon do you cover?
We cover LL55, along with the rest of Gwynedd. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
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.
Do you cover Bangor, Gwynedd, Holyhead and Llandudno?
Yes. As well as Caernarfon, we cover Bangor, Gwynedd, Holyhead and Llandudno and the rest of Gwynedd. 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 £4,100–£8,300, 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.
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.
Near Caernarfon
Caernarfon and its LL55 postcodes are part of our coverage. Homeowners in Bangor, Gwynedd, Holyhead and Llandudno can also book a free survey with us and receive a written price for their job.