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.
We take on replacement windows throughout Barnet and the surrounding EN4, EN5, N3 and N12 postcodes, as well as in East Barnet, Hadley Wood and Potters Bar. The guide range for this work in London is £5,800–£11,500 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £5,800–£11,500 inc VAT
- Time on site
- 1–2 days on site for a typical house
- Postcodes
- EN4, EN5, N3, N12 and N20
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
How much do replacement windows cost in Barnet?
The table below shows guide prices for replacement windows in Barnet. They are based on rates in London, which run about 30% above the national guide, giving an overall range of £5,800–£11,500. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Barnet |
|---|---|---|
| One to three windows | Replacing a few problem windows, such as a bay or a rotten kitchen window, in uPVC. | £900–£3,900 |
| Whole house in uPVC | Eight to ten standard uPVC casement windows on a typical 3-bed semi, fitted and finished. | £5,800–£9,800 |
| Whole house in aluminium or flush sash | Premium frames, colours or period styles across a typical 3-bed home. | £9,800–£18,000 |
Your price depends mostly on:
- Number and size of windows, including bays and large picture windows
- Frame material, colour and finish, inside and out
- 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 Barnet?
- 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
- Fixings, packers, foam and weather seals to suit your wall type
- New internal trims, external cills and neat sealant finishing
- Building regulations sign-off arranged and paperwork handed over
What are homes like around Barnet?
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
Terraces suit side-return extensions and rear dormer loft conversions; interwar semis commonly take hip-to-gable lofts. Shared party walls, restricted parking and conservation rules often shape the plans and the programme.
If your house in Barnet fits one of these patterns, it helps us anticipate what replacement windows will involve, though we always confirm the details on site.
Permissions for replacement windows in Barnet
Homes in Barnet come under the regulations for England, 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.
Replacing windows and doors on a house is usually permitted development in England when the new ones look broadly similar to the old. Flats, listed buildings and homes covered by an Article 4 direction can need consent, and conservation areas may limit materials or styles.
Replacement windows and external doors must meet Building Regulations for energy efficiency, ventilation and, on upper floors, escape. The work is either self-certified by an installer registered with a competent person scheme or signed off by building control.
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
First, someone visits your home in Barnet to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Your fixed price
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Booking the work
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.
Build and hand over
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
What you can expect from us
Questions about replacement windows in Barnet
Do I need planning permission in Barnet?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Barnet is in England, so England'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.
What happens on the day the windows are fitted?
On fitting day we lay dust sheets, protect floors and furniture near each window, and then remove the old frame carefully to limit damage to plaster. The new frame is fixed, packed, sealed and glazed, and internal trims and external cills are finished. We take away the old windows and clean the glass before leaving. You only need to clear sills and take down curtains and blinds.
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.
Which postcodes in Barnet do you cover?
We cover EN4, EN5, N3 and N12, along with the rest of London. 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.
Also covering areas around Barnet
Whether you're in the centre of Barnet or on its outskirts, EN4, EN5, N3 and N12 addresses are covered. We extend the same service, and the same fixed-price approach, to East Barnet, Hadley Wood and Potters Bar.