London · 2026 Guide
Do I Need Planning Permission for New Windows in London?
The direct answer
Short answer
In most cases NO — replacement windows fall under permitted development. You DO need permission if: the property is listed (Listed Building Consent), it sits in a conservation area with an Article 4 Direction, you are replacing front-elevation windows on a flat, or you are changing the size or character of the opening.
Building Regulations always apply. A FENSA-registered installer (Apex Glazing is FENSA Reg 40373) self-certifies the work and notifies your local authority — no separate Building Control application needed.
When permission is NOT required
These scenarios fall under permitted development rights granted by the Town and Country Planning (General Permitted Development) Order 2015, Schedule 2, Part 1, Class A (and Class C for windows). No application needed.
| Scenario | Why allowed |
|---|---|
| Like-for-like replacement on a freehold house | Permitted development under Class A — same opening, same character |
| Upgrading single glazing to double glazing | Permitted as long as appearance broadly matches |
| Rear elevation of a house in a standard conservation area | Allowed without Article 4 Direction |
| Internal secondary glazing | Always permitted — no external change |
| Side windows not facing the highway | Permitted on most freehold houses |
| Replacing modern uPVC with new uPVC, like-for-like | Material is unchanged — falls under PD |
When permission IS required
These scenarios always need either Listed Building Consent, Householder Planning Permission, or both. Starting work without consent risks enforcement action and reversal at your cost.
| Scenario | Consent required | Fee (2026) |
|---|---|---|
| Listed building (Grade I, II*, II) | Listed Building Consent | £0 |
| Conservation area with Article 4 Direction | Householder Planning Permission | £206 |
| Flat or maisonette — front elevation | Householder Planning Permission | £206 |
| Enlarging the opening | Householder Planning Permission | £206 |
| Adding a new opening (not replacing) | Householder Planning Permission | £206 |
| Changing material on a heritage frontage | Householder Planning Permission | £206 |
| Restrictive covenant on the title | Freeholder consent + possible PP | Varies |
London conservation areas to watch
London has roughly 1,000 conservation areas across 33 boroughs. Many have Article 4 Directions covering windows. These are the ones we're most often asked about — always verify by searching your address on your borough's planning portal.
| Area | Borough | Postcode | Status |
|---|---|---|---|
| Bedford Park | Hounslow / Ealing | W4 | Article 4 — windows controlled |
| Strawberry Hill | Richmond upon Thames | TW1 | Article 4 — windows controlled |
| Richmond Green | Richmond upon Thames | TW9 | Conservation — extra care |
| Chiswick Mall | Hounslow | W4 | Article 4 — windows controlled |
| Hampstead | Camden | NW3 | Multiple Article 4 zones |
| Highgate | Camden / Haringey | N6 | Article 4 — windows controlled |
The application process
If you do need permission, here's the realistic timeline. Apex Glazing prepares supporting drawings, window schedules, and material specifications free of charge when we're installing the windows.
| Step | Time | Notes |
|---|---|---|
| Pre-application advice (optional) | 2–4 weeks | £80–£250 depending on borough |
| Submit application via Planning Portal | 1 day | £206 fee, drawings, photos, design statement |
| Validation by council | 5–10 working days | Council confirms application is complete |
| Public consultation | 21 days | Statutory neighbour notification |
| Conservation officer review | 1–3 weeks | If applicable — runs in parallel |
| Decision | 8 weeks total | From validation to determination |
| Implementation window | 3 years | From the decision date |
Frequently asked
Do I need planning permission to replace windows in London?
In most cases no. Like-for-like replacement windows on a freehold house fall under permitted development rights and do not need planning permission, provided the property is not listed, not in an Article 4 conservation area, and the size and character of the openings are not changed. You do still need Building Regulations sign-off, which a FENSA-registered installer like Apex Glazing handles via self-certification.
Do I need planning permission for double glazing?
No, double glazing on a standard freehold house in London does not require planning permission as long as the new units broadly match the appearance of the existing windows. Listed buildings need Listed Building Consent regardless. Properties in conservation areas with an Article 4 Direction also need permission, even for double glazing.
Do I need planning permission for replacement windows in a flat?
Yes, often. Flats and maisonettes do not benefit from the householder permitted development rights that apply to houses. Replacing front-elevation windows on a flat usually requires planning permission from the local council. Rear and side windows may be allowed under your lease, but the freeholder's consent is also needed. Always check both the lease and the council's planning portal first.
Do I need permission for windows in a conservation area?
It depends on whether the conservation area has an Article 4 Direction. A standard conservation area without Article 4 still allows like-for-like replacement under permitted development. With Article 4, normal permitted development rights are removed and you must apply for planning permission for any window change. Most London conservation areas with Article 4 are listed on each borough's website.
What is an Article 4 Direction?
An Article 4 Direction is a power used by London councils to remove permitted development rights in specific conservation areas. It means homeowners must apply for planning permission for changes that would normally be free, including replacement windows, doors, roof tiles, and front boundary walls. Bedford Park (W4), Chiswick Mall (W4), and parts of Hampstead and Highgate all sit under Article 4 Directions.
How much does planning permission cost for windows in London?
A householder planning application costs £206 in 2026 (Town and Country Planning fees, England). Listed Building Consent is free of charge. Pre-application advice from London boroughs typically costs £80–£250. Apex Glazing assists with drawings and supporting documents at no extra cost when we are installing the windows.
How long does planning permission take for windows?
Statutory determination period is 8 weeks for a householder application in England. In practice, simple window applications in London are decided in 5–8 weeks. Listed Building Consent runs in parallel and is also 8 weeks. Conservation area consultation can add 1–2 weeks. Always plan your installation 10–12 weeks after the application is validated.
Do I need Listed Building Consent for windows?
Yes. Any work to a listed building that affects its character, including replacing windows, requires Listed Building Consent under the Planning (Listed Buildings and Conservation Areas) Act 1990. This applies to all grades — Grade I, Grade II*, and Grade II — and to internal as well as external windows. Carrying out work without consent is a criminal offence.
Can I install uPVC windows in a conservation area?
Sometimes yes, often no. In conservation areas without Article 4, like-for-like uPVC replacement of existing uPVC windows is usually permitted. Replacing original timber sash windows with uPVC is rarely approved on front elevations. Article 4 conservation areas almost always require timber or heritage-grade aluminium that visually replicates the original. Apex Glazing's heritage uPVC and heritage aluminium ranges are commonly approved in London conservation areas.
