Double glazing quotes in Barnet
Compare free written quotes from local installers who cover your EN, N, NW or HA postcode, for replacement windows, timber replicas, secondary glazing and repairs. Nearly half of Barnet households live in flats, and nine conservation areas control window changes on houses.
651 listed buildings in Barnet, where window changes need listed building consent
- Free and no obligation. Compare first, decide later
- Secondary glazing quoted for listed and protected homes
- Flats welcome once the freeholder has agreed
How it works
How Barnet double glazing quotes reach you
Tell us about the job
Property type, how many windows, frame material and when you want them fitted. It takes about a minute.
We confirm the details
A quick call checks what you need, then your enquiry goes to local installers who cover your postcode.
Compare like for like
Each installer surveys and quotes in writing. Check every quote against our quote comparison checklist before you sign anything.
What you can get quoted for
What you can get quoted for in Barnet
Barnet installers quote for replacement windows, secondary glazing, glass-only units and repairs from one enquiry:
- Replacement windows in uPVC, aluminium or timber for houses with no controls;
- Timber replicas and sashes for Mill Hill, Totteridge, Monken Hadley and other Article 4 areas, compared under sash window replacement;
- Secondary glazing for listed homes and original frames you keep;
- Sealed-unit replacement for misted panes;
- Repairs to hinges, locks, handles and seals.
Ask the installer whether a door can go on the same quote. In Article 4 areas Design Guidance Note 6 treats doors the same way as windows.
Get Barnet window quotesFree, no obligation
Local factors
What changes a Barnet double glazing quote
Five things change a Barnet quote: Article 4 controls, listed status, Hampstead Garden Suburb, flats and inter-war bays. Check your address against them before anyone surveys.
| In Barnet | What it changes in your quote | Ask or check |
|---|---|---|
| 9 Article 4 conservation areasBarnet Council | Planning permission to change windows on a house | Application drawings in the quote |
| 651 listed buildingsBarnet Council | Listed building consent for window changes | Secondary glazing fitted in listed homes before |
| Two approvals in Hampstead Garden SuburbBarnet Council | Council and Trust consent, even for repairs | Who submits the drawings to each body |
| 47.4% of households in flatsCensus 2021 | Freeholder's written consent, and often planning permission | Who owns the frames under the lease |
| 33.8% of properties built 1919 to 1939VOA 2025 | Inter-war bays that may need structural support | Each bay priced as its own line |
Planning
Do you need permission to replace windows in Barnet?
You need planning permission to change windows on a house in nine Barnet conservation areas where an Article 4 direction removes the usual householder right, and listed building consent on any of 651 listed buildings. Barnet says 10 of its 16 conservation areas have Article 4 directions in force. One of them, Glenhill Close, controls only gates and fences.
| Conservation area | Window control |
|---|---|
| Hampstead Garden Suburb | Alterations to houses removed from permitted development, plus Trust consent |
| Finchley Church End | Named properties only, on frontages facing a highway, waterway or open space |
| Finchley Garden Village | Alterations to houses |
| Hendon The Burroughs | Alterations to houses |
| Mill Hill | Alterations to houses (two directions) |
| Monken Hadley | Alterations to houses (two directions) |
| Moss Hall Crescent | Alterations to houses |
| Totteridge | Alterations to houses (two directions) |
| Wood Street | Alterations to houses |
Barnet's Design Guidance Note 6 says that in these areas "planning permission will normally be required for alteration to windows and doors", and that original windows should be "retained or closely copied". In Finchley Church End the direction names specific homes, such as 9 and 10 College Terrace, 1 to 4 Park Cottages and 28 Hendon Lane.
- Check your address against the council's Article 4 data and conservation area map.
- Ask installers whether they prepare drawings for a planning application, and whether that is in the quote.
- Ask for timber or flush-casement replicas of the originals, not standard uPVC profiles.
Get Barnet conservation area quotesFree, no obligation
Hampstead Garden Suburb
Window quotes in Hampstead Garden Suburb: council and Trust consent
A window change in Hampstead Garden Suburb needs two approvals: planning permission from Barnet under the Article 4 direction, and consent from the Hampstead Garden Suburb Trust. Barnet's guidance states that "any external change to a property, including restoration of original work, will require the prior consent of the Hampstead Garden Suburb Trust".
Even a like-for-like repair counts. Ask installers for the addresses of Trust-approved jobs they have done in the Suburb, and who will submit the drawings to each body. Leave time for both decisions before you agree a fitting date.
Get Hampstead Garden Suburb quotesFree, no obligation
Flats and leasehold
Double glazing quotes for Barnet flats and leaseholders
A Barnet flat needs the freeholder's written consent before new windows, and often planning permission. 47.4% of Barnet households live in a flat or maisonette: 36.6% in purpose-built blocks and 9.5% in converted or shared houses (Census 2021).
Permitted development rights for windows apply to houses, not flats. The Planning Portal says you "may need to apply for planning permission to fit new windows (such as double-glazing) in your flat or maisonette", and that leaseholders "may first need to get permission from your landlord, freeholder or management company".
- Check the lease to see who owns the window frames.
- Get consent and the block's window specification in writing.
- Ask each installer whether the quote assumes a like-for-like swap or includes drawings for a planning application.
Our guide to replacing windows in a leasehold flat covers licences for alterations and who pays.
Get quotes for a Barnet flatFree, no obligation
Barnet homes
Replacement windows for Barnet's 1930s semis and rented homes
Barnet houses are mostly inter-war, and a third of its households rent privately.
| Measure | Barnet | London |
|---|---|---|
| Properties built 1919 to 1939 | 33.8% | 22.2% |
| Households in a semi-detached house | 27.5% | 18.6% |
| Households renting privately | 32.7% | 30.0% |
| EPC band C or above, all homes | 58.2% | 57.9% |
| EPC band C or above, homes built before 1929 | 26.4% | n/a |
- Inter-war bays: ask for each bay priced as its own line, any structural support, and how leaded or coloured top lights will be matched. A new bay "will be treated as an extension and may require permission", according to the Planning Portal.
- Landlords: privately rented homes must reach EPC band C or register an exemption by 1 October 2030 (DESNZ, January 2026). Ask for each window's U-value or Window Energy Rating in writing.
- Older homes: only 26.4% of Barnet's pre-1929 homes reach band C, so the window rating matters most in Victorian and Edwardian streets.
Get quotes for a 1930s semiFree, no obligation
Repair or replace?
Repair, replace or secondary glaze in Barnet?
Repair or secondary glaze when the window is original or listed, reglaze when only the glass has failed, and replace when the frame is beyond repair. Barnet's guidance says "replacement windows will only be necessary when the originals are in such poor state of repair as to be no longer repairable", and names "the use of secondary glazing" as another method.
| Your window | Route | Ask the installer |
|---|---|---|
| Listed building, any window | Secondary glazing or repair, with listed building consent | Whether they have fitted secondary glazing in listed homes |
| Original timber in an Article 4 area | Repair, or a close copy with permission | A repair price and a replica price side by side |
| Sound frame, misted glass | Sealed-unit replacement | The guarantee on the new unit |
| Failed uPVC or rotten frame, no controls | Full replacement | The whole-window U-value in writing |
"Double glazing repairs Barnet" is a common Google suggestion, and repair firms appear in the borough's local map results. Our page on window repair or replacement in London compares the routes side by side.
Get Barnet repair or replacement quotesFree, no obligation
Before you sign
How to check a Barnet double glazing company
Check a Barnet company on the FENSA or CERTASS register, on Companies House and against a written insurance-backed guarantee, before it surveys. London Trading Standards warns that "there are more rogue traders offering insulation, double glazing, solar panels and heat pumps", so start from installers you contacted.
- Search the firm on fensa.org.uk or certass.co.uk. Registration lets it self-certify replacement windows under Building Regulations.
- Check Companies House for an active company, its incorporation date and earlier names.
- For conservation or listed work, ask for addresses of similar Barnet jobs and the planning reference for one of them.
- Get the insurance-backed guarantee named in writing, with its length.
- Compare itemised quotes with our guide on how to compare double glazing quotes.
If you sign at home, you usually have at least 14 days to cancel, but made-to-measure windows can be an exception, so check the contract before you sign. Our double glazing cooling off period guide explains it, and how to choose a double glazing installer has the full checklist.
Areas
Areas this page covers in Barnet
This page is about the London Borough of Barnet, from High Barnet in the north to Golders Green and Cricklewood in the south. Enter your postcode in the form to find out whether a local installer covers it. We are a free quote-matching service, not an installer.
| Postcode district | Places |
|---|---|
| EN5 | High Barnet, New Barnet, Arkley, Monken Hadley |
| EN4 (part) | East Barnet, Cockfosters |
| N2 and N3 | East Finchley, Finchley Central (Church End) |
| N11 (part) and N12 | Friern Barnet, North Finchley, Woodside Park |
| N20 | Whetstone, Totteridge, Oakleigh Park |
| NW4 and NW7 | Hendon, Mill Hill |
| NW9 (part) and HA8 (part) | Colindale, West Hendon, Edgware, Burnt Oak |
| NW11 and NW2 (part) | Golders Green, Hampstead Garden Suburb, Cricklewood |
Nearby areas
FAQ
Double glazing in Barnet: questions answered
Do I need planning permission for new windows in Barnet?
A Barnet house in one of nine Article 4 conservation areas needs planning permission for new windows, a listed building needs listed building consent, and a flat usually needs permission and freeholder consent. Other houses need none for a similar-looking replacement.
What are people saying about Martin Lewis at Help to Buy windows?
People are reporting fake adverts: MoneySavingExpert says Martin Lewis "doesn't do ads", so any Help to Buy windows offer using his name is a scam.
What is the best time of year to buy double glazing?
The best time in Barnet is once any planning, Trust or freeholder consent is in hand, because a fitting date before approval is worthless. Our guide to the best time of year to buy double glazing found no proven cheapest month.
Can I replace just the misted glass?
Yes. A misted pane in a sound frame is fixed by a new sealed unit, which leaves the frame, hinges and locks in place.
Is it worth replacing 20 year old double glazing?
Replacing 20 year old double glazing makes sense only when the frames have failed; in Barnet's Article 4 areas the council expects repair first and a close copy second.
What are the disadvantages of double glazing?
Double glazing's disadvantages are sealed units that mist when their seals fail, standard uPVC profiles that do not copy original Barnet windows, and the permission or consent needed in Article 4 areas, listed buildings and flats.
What is the average price of double glazing?
The average hides big differences in window count, material and consent work, so compare itemised quotes and see what double glazing costs in London on our sister site.
Sort consent, then compare Barnet quotes
Tell us the property, window count and frame material. Installers covering your EN, N, NW or HA postcode survey and send written prices. For airport schemes and rules across the capital, see double glazing quotes in London.
Get free quotes
Sources
Figures checked 1 October 2026.
- Barnet Council, conservation areas and Hampstead Garden Suburb
- Barnet Council, Article 4 direction documentation (open data), including the Finchley Church End direction
- Barnet Council, Design Guidance Note 6: the replacement of windows and doors
- Barnet Council, statutory listed buildings (open data, 651 entries)
- Planning Portal, change the windows of a flat and doors and windows
- Valuation Office Agency, Council Tax stock of properties 2025, table CTSOP4.1
- ONS, Census 2021 tables TS044 accommodation type and TS054 tenure
- ONS, EPC band C or above, England and Wales, tables 2a and 2c, to March 2025
- DESNZ, Improving the energy performance of privately rented homes: government response (21 January 2026)
- London Trading Standards, doorstep crime campaign (18 May 2022)
- MoneySavingExpert, Martin Lewis scam adverts
- FENSA, fensa.org.uk; CERTASS, certass.co.uk; Companies House, company search