Which postcode districts around Camden do we cover for basement extension work?
Every Camden postcode district we draw in, the stock that dominates
it and the authority that validates a basement extension there. Camden fees below are the
statutory England rates for 2026, not basement extension estimates.
| Postcode | Area | Dominant stock | What it means for a basement extension |
|---|
| N19 | Archway / Tufnell Park | Victorian terraces, post-war flats | A basement extension in Archway / Tufnell Park may land with Islington Council or Camden Council — N19 crosses the boundary, and the N19 policies map decides it street by street. |
| NW2 | Cricklewood / Neasden | Edwardian villas and terraces | Cricklewood / Neasden is split at NW2. Either Brent Council or Barnet Council or Camden Council can determine a basement extension here, so the NW2 address is checked against both policies maps first. |
| NW8 | St John's Wood | Victorian villas, mansion blocks | St John's Wood is split at NW8. Either Westminster City Council or Camden Council can determine a basement extension here, so the NW8 address is checked against both policies maps first. |
| WC2B | Covent Garden / Holborn | Victorian and Edwardian terraces | Covent Garden / Holborn is split at WC2B. Either Westminster City Council or Camden Council can determine a basement extension here, so the WC2B address is checked against both policies maps first. |
| N1C | King's Cross | Modern apartments, converted warehouses | N1C covers King's Cross only; Camden Council handles the basement extension. |
| N6 | Highgate | Georgian villas, Victorian and Edwardian semis | Highgate is split at N6. Either Camden Council or Haringey Council can determine a basement extension here, so the N6 address is checked against both policies maps first. |
| NW1 | Camden Town / Regent's Park | Victorian terraces, mansion blocks | A basement extension in Camden Town / Regent's Park may land with Camden Council or Westminster City Council — NW1 crosses the boundary, and the NW1 policies map decides it street by street. |
| NW3 | Hampstead / Belsize Park | Georgian and Victorian villas, listed buildings | Hampstead / Belsize Park sits wholly inside NW3, so Camden Council validates every basement extension submitted from an NW3 address. |
How does a basement extension differ street by street across Camden?
Roof pitch, wall build-up and plot depth change every few Camden
streets, and each one changes what a basement extension can achieve at that address.
- Gospel Oak (NW5) — Victorian terraces and estates near the Heath defines Gospel Oak, where victorian terraces, post-war estates set what a basement extension can do. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged across NW5. Any Gospel Oak basement extension is validated by Camden Council, with Gospel Oak station the usual Gospel Oak reference point on the site plan.
- West Hampstead (NW6) — Victorian and Edwardian villa streets defines West Hampstead, where edwardian mansion blocks, victorian villas set what a basement extension can do. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged across NW6. Any West Hampstead basement extension is validated by Camden Council, with West Hampstead Thameslink the usual West Hampstead reference point on the site plan.
- Camden Town (NW1) — dense mixed-use, Victorian terraces, canal-side defines Camden Town, where victorian terraces, mansion blocks set what a basement extension can do. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged across NW1. Any Camden Town basement extension is validated by Camden Council, with Camden Market the usual Camden Town reference point on the site plan.
- Hampstead (NW3) — basement extension work in Hampstead means georgian and victorian villas, listed buildings. Hampstead is affluent, listed Georgian and Victorian villas. Georgian houses here already have a vault and a lower-ground floor throughout NW3. Camden Council decides the Hampstead application, and Hampstead Heath anchors the Hampstead location plan.
- Primrose Hill (NW1) — boutique village atmosphere, painted terraces defines Primrose Hill, where victorian and edwardian terraces set what a basement extension can do. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged across NW1. Any Primrose Hill basement extension is validated by Camden Council, with Primrose Hill park the usual Primrose Hill reference point on the site plan.
- Kentish Town (NW5) — basement extension work in Kentish Town means victorian terraces. Kentish Town is Victorian terraced streets, gentrifying. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged throughout NW5. Camden Council decides the Kentish Town application, and Kentish Town City Farm anchors the Kentish Town location plan.
- Belsize Park (NW3) — basement extension work in Belsize Park means edwardian mansion blocks, victorian villas. Belsize Park is tree-lined avenues, Edwardian mansion blocks. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged throughout NW3. Camden Council decides the Belsize Park application, and Belsize Park station anchors the Belsize Park location plan.
What local planning policy applies to a basement extension in Camden?
How designation changes a Camden basement extension: Camden Council maintains 40 conservation areas, including Bloomsbury, Camden Town, Fitzrovia. Inside any of them a Camden basement extension cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Fitzrovia sets the tone for Camden casework.
What Article 4 removes near Camden: Article 4 removes permitted development for HMO conversions (C3 to C4) across the borough, plus restrictions on basement extensions in 12 conservation areas. Before pricing a basement extension we check whether the N1C address is inside the mapped area, because Camden Council draws the Camden boundary street by street rather than across the whole of Camden.
Camden below-ground policy: Camden's basement policy (Policy A5) restricts single-storey basements to 50% of garden area; double-storey basements generally refused outside commercial zones. Any basement extension in Camden that goes below existing foundations triggers two months notice under section 6 of the Party Wall etc. Act 1996, and Camden Council will want the N1C ground and groundwater position set out.
The building fabric around Camden: Victorian and Edwardian terraces, Georgian townhouses in Bloomsbury and Hampstead, post-war mansion blocks, modern developments in King's Cross. Creative, affluent in Hampstead and Primrose Hill; dense mixed-use around Camden Town and Kings Cross; academic character in Bloomsbury. A basement extension in Camden is scoped against that stock first.
Who decides a basement extension on the edge of Camden?
- City of London — adjoining Camden, with 27 conservation areas centred on EC1. A basement extension on the far side of the Camden line is determined by City of London Corporation, so the Camden quote for basement extensions is checked against City of London guidance before it is issued.
- Westminster — the Westminster boundary runs against Camden, so a basement extension a street from Camden is decided by Westminster City Council instead. Westminster runs 56 conservation areas across SW1 and its neighbours, which is why basement extensions priced for Camden are re-checked against Westminster policy whenever the Camden address sits on that edge.
- Islington — the Islington boundary runs against Camden, so a basement extension a street from Camden is decided by Islington Council instead. Islington runs 40 conservation areas across N1 and its neighbours, which is why basement extensions priced for Camden are re-checked against Islington policy whenever the Camden address sits on that edge.
- Barnet — the Barnet boundary runs against Camden, so a basement extension a street from Camden is decided by Barnet Council instead. Barnet runs 20 conservation areas across N2 and its neighbours, which is why basement extensions priced for Camden are re-checked against Barnet policy whenever the Camden address sits on that edge.
Sources for this Camden basement 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.
