House Extensions · NW10 Willesden
NW10 borders the major Old Oak Park Royal regeneration; Brent applies suburban householder control across the residential streets.
The borough-level guide to house extensions in Brent sets out how the same work is handled across the rest of the authority.
House extensions in Willesden are dominated by single-storey rear and side-return additions on NW10's victorian and edwardian terraces, inter-war semis and, with double-storey and wrap-around schemes where the plot allows. Brent Council weighs depth, height and neighbour daylight; many extensions across Willesden, Harlesden, Kensal Green, Park Royal fringe, Willesden Green are Permitted Development, which we confirm with a Lawful Development Certificate before you build.
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for victorian and edwardian terraces, inter-war semis and typical of Willesden.
Across Willesden, Harlesden, Kensal Green, Park Royal fringe, Willesden Green in NW10, the dominant property is victorian and edwardian terraces, inter-war semis and substantial industrial-to-residential conversions across willesden, harlesden and kensal green. That stock shapes what house extension drawings looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Brent Council judges each on design quality and neighbour impact. We survey the specific Willesden property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the NW10 streetscape.
Housing stock in NW10: Victorian and Edwardian terraces, inter-war semis and substantial industrial-to-residential conversions across Willesden, Harlesden and Kensal Green.
Within the district: Willesden, Harlesden, Kensal Green, Park Royal fringe, Willesden Green.
Streets we know in NW10: the Kensal Green terraces, Chamberlayne Road, Doyle Gardens and the Willesden Green streets. Each road has its own building line, boundary treatment and precedent that Brent Council weighs when assessing a house extension drawings scheme.
Conservation areas: Kensal Green, Roundwood, Harlesden. Inside these, most external work needs full planning and a Heritage Statement.
Getting around NW10: Willesden Junction, Kensal Green and Willesden Green on the Bakerloo, Jubilee and Overground.
Regeneration: Willesden falls within or beside the Old Oak and Park Royal (OPDC) Opportunity Area, one of the UK's largest, which shapes local planning policy and design expectations.
Property values: the middle half of 2025 NW10 sales ran between £392,000 and £854,000 — a £462,000 spread across 492 transactions in the Land Registry file. The median landed at £580,000. That range covers everything from studio flats to large houses.
Borough character: Highly diverse borough; Queen's Park and Mapesbury are heritage-controlled; Wembley is a major regeneration hub.
Measured existing survey, photographic record, Article 4 and conservation check specific to Willesden before we quote.
2–3 design options at concept stage — alternative layouts, glazing, roof forms.
Site location plan, existing and proposed plans, elevations, sections, D&AS where required.
Part L thermal, Part B fire, Part M accessibility, structural strategy.
Steel beam, foundation, lintel design. Chartered engineer sign-off.
Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.
Yes. The Victorian and Edwardian terraces around Chamberlayne Road and Doyle Gardens suit side-return and rear extensions plus loft conversions, much of it Permitted Development outside the conservation areas, confirmed with a Lawful Development Certificate. We confirm the route and draw to Brent's checklist.
OPDC is one of the UK's largest regeneration schemes — tens of thousands of new homes and an Elizabeth line / HS2 interchange — lifting values across NW10. For a house project it mainly improves the backdrop; your scheme is still governed by Permitted Development limits and Brent householder policy, which we apply.
Usually yes — a rear dormer (and hip-to-gable on the semis) within the volume allowance, confirmed by a Lawful Development Certificate, provided you're not in the Kensal Green or Roundwood conservation areas. We check the constraints for your road and draw it for Building Control.
With houses around £650,000-£900,000 and the OPDC regeneration improving the area, a well-designed rear extension or loft adds family space worth comfortably above the build and drawing cost.
Brent Council charges its own statutory application fee (currently £548 for a householder planning application, £610 for a full application). We quote the drawings as one fixed price and the free site survey covers every NW10 address.
For a NW10 project across Willesden, Harlesden, Kensal Green, Park Royal fringe, Willesden Green, expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Brent Council (8 weeks for a householder application). We carry the Willesden application through every officer query to the decision.
Willesden (NW10) sits primarily in Brent, so applications are decided by Brent Council. Conservation areas within NW10 include Kensal Green, Roundwood, Harlesden, where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind house extension drawings in Willesden — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Brent Council Building Control or an approved inspector. On NW10's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on NW10 homes.
Planning history and precedent stop at the borough line, so the comparable approvals nearby may sit elsewhere. See all services in NW2 and NW6.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every NW10 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. NW10 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| NW10 | Willesden / Harlesden / Kensal Green | Modern apartments, post-war estates | Willesden / Harlesden / Kensal Green is split at NW10. Either Brent Council or Ealing Council can determine a house extension here, so the NW10 address is checked against both policies maps first. |
| NW10 | Harlesden | Victorian terraces | Harlesden sits inside NW10; house extension proposals here are determined by Brent Council. |
| NW10 | Kensal Green | Victorian terraces | Kensal Green sits inside NW10; house extension proposals here are determined by Brent Council. |
| NW10 | Willesden | Victorian terraces, Edwardian terraces | Willesden sits inside NW10; house extension proposals here are determined by Brent Council. |
| NW10 | Neasden | 1930s semi-detached, post-war | Neasden sits inside NW10; house extension proposals here are determined by Brent Council. |
| NW10 | Park Royal | Modern apartments, post-war estates | Park Royal sits inside NW10; house extension proposals here are determined by Ealing Council. |
| NW2 | Cricklewood / Neasden | Edwardian villas and terraces | Adjoining district to NW10, also inside Brent for house extension purposes. |
| HA0 | Wembley / Sudbury | 1930s semi-detached, new-build | Adjoining district to NW10, also inside Brent for house extension purposes. |
| HA9 | Wembley / Wembley Park | 1930s semi-detached, new-build | Adjoining district to NW10, also inside Brent for house extension purposes. |
| W3 | Acton | Victorian and Edwardian terraces | Adjoining district to NW10, also inside Ealing for house extension purposes. |
| W5 | Ealing | Edwardian villas, Victorian terraces | Adjoining district to NW10, also inside Ealing for house extension purposes. |
| W7 | Hanwell | Edwardian villas, 1930s semi-detached | Adjoining district to NW10, also inside Ealing for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few NW10 streets, and each one changes what a house extension can achieve at that address.
Conservation areas covering NW10 (Willesden / Harlesden / Kensal Green): Brent Council runs 22, and Queen's Park, Mapesbury, Kensal Green are the ones NW10 (Willesden / Harlesden / Kensal Green) owners meet most. A house extension inside a NW10 (Willesden / Harlesden / Kensal Green) conservation area loses permitted development, so the NW10 (Willesden / Harlesden / Kensal Green) submission is a householder application at £548 decided in 8 weeks — not a £249 prior approval decided in 6 weeks. In Sudbury Court a house extension is judged on the street elevation first.
What Article 4 removes near NW10 (Willesden / Harlesden / Kensal Green): Article 4 for HMO conversions in specific streets around Wembley and Harlesden. Before pricing a house extension we check whether the NW10 address is inside the mapped area, because Brent Council draws the NW10 (Willesden / Harlesden / Kensal Green) boundary street by street rather than across the whole of NW10 (Willesden / Harlesden / Kensal Green).
The building fabric around NW10 (Willesden / Harlesden / Kensal Green): Edwardian villas in Queen's Park and Mapesbury; Victorian terraces in Kilburn and Harlesden; 1930s semi-detached in Wembley; post-war tower blocks in Church End. Highly diverse borough; Queen's Park and Mapesbury are heritage-controlled; Wembley is a major regeneration hub. A house extension in NW10 (Willesden / Harlesden / Kensal Green) is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Brent Council.
Conservation areas covering NW10 (Willesden / Harlesden / Kensal Green): Ealing Council runs 30, and Ealing Broadway, Pitshanger, Bedford Park are the ones NW10 (Willesden / Harlesden / Kensal Green) owners meet most. A house extension inside a NW10 (Willesden / Harlesden / Kensal Green) conservation area loses permitted development, so the NW10 (Willesden / Harlesden / Kensal Green) submission is a householder application at £548 decided in 8 weeks — not a £249 prior approval decided in 6 weeks. In Hanwell a house extension is judged on the street elevation first.
What Article 4 removes near NW10 (Willesden / Harlesden / Kensal Green): Article 4 for HMOs in specific streets in Acton, Ealing and Southall. Before pricing a house extension we check whether the NW10 address is inside the mapped area, because Ealing Council draws the NW10 (Willesden / Harlesden / Kensal Green) boundary street by street rather than across the whole of NW10 (Willesden / Harlesden / Kensal Green).
The building fabric around NW10 (Willesden / Harlesden / Kensal Green): Victorian and Edwardian villas in Ealing central; 1930s semi-detached in Northolt and Hanwell; mansion blocks along main roads; Bedford Park is a listed Arts & Crafts garden suburb. Leafy outer-west London; Bedford Park conservation area has strict heritage controls; rest of borough generally permissive. A house extension in NW10 (Willesden / Harlesden / Kensal Green) is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Ealing Council.
Sources for this NW10 house extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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