Wrap-around extension in Westminster

Which Westminster postcodes does this wrap around extension service cover?

Every Westminster postcode district we draw in, the stock that dominates it and the authority that validates a wrap around extension there. Westminster fees below are the statutory England rates for 2026, not wrap around extension estimates.

How does a wrap around extension differ street by street across Westminster?

Roof pitch, wall build-up and plot depth change every few Westminster streets, and each one changes what a wrap around extension can achieve at that address.

• Maida Vale (W9) — Edwardian mansion blocks, canal-side defines Maida Vale, where edwardian mansion blocks, victorian villas set what a wrap around extension can do. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage across W9. Any Maida Vale wrap around extension is validated by Westminster City Council, with Little Venice the usual Maida Vale reference point on the site plan.
• Mayfair (W1J, W1K) — wrap around extension work in Mayfair means georgian townhouses, listed buildings. Mayfair is Georgian listed townhouses, luxury. Georgian rear elevations here are usually the listed or locally listed face of the building throughout W1J. Westminster City Council decides the Mayfair application, and Berkeley Square anchors the Mayfair location plan.
• Belgravia (SW1X, SW1W) — white stucco Regency terraces defines Belgravia, where regency stucco terraces, listed buildings set what a wrap around extension can do. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage across SW1X. Any Belgravia wrap around extension is validated by Westminster City Council, with Eaton Square the usual Belgravia reference point on the site plan.
• Marylebone (W1U, W1G, W1H) — wrap around extension work in Marylebone means georgian terraces, edwardian mansion blocks. Marylebone is Georgian and Victorian terraces, mansion blocks. Georgian rear elevations here are usually the listed or locally listed face of the building throughout W1U. Westminster City Council decides the Marylebone application, and Marylebone High Street anchors the Marylebone location plan.
• Pimlico (SW1V) — a wrap around extension in Pimlico starts from regency terraces, post-war estates, and Pimlico reads as Regency stucco terraces, grid plan. Post-war houses on these estates often sit under an estate management scheme in SW1V. Westminster City Council assesses Pimlico wrap around extensions against its own Pimlico character guidance, and the location plan we draw for Pimlico references Tate Britain.
• Soho (W1D, W1F) — wrap around extension work in Soho means georgian terraces, mixed-use. Soho is Georgian fragments, mixed-use. Georgian rear elevations here are usually the listed or locally listed face of the building throughout W1D. Westminster City Council decides the Soho application, and Soho Square anchors the Soho location plan.
• Covent Garden (WC2E, WC2H) — Georgian piazza, listed buildings defines Covent Garden, where georgian terraces, conversions set what a wrap around extension can do. Georgian rear elevations here are usually the listed or locally listed face of the building across WC2E. Any Covent Garden wrap around extension is validated by Westminster City Council, with Royal Opera House the usual Covent Garden reference point on the site plan.

What local planning policy applies to a wrap around extension in Westminster?

How designation changes a Westminster wrap around extension: Westminster City Council maintains 56 conservation areas, including Soho, Covent Garden, St John's Wood. Inside any of them a Westminster wrap around 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. Marylebone sets the tone for Westminster casework.

Article 4 and your Westminster wrap around extension: Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones. At a NW8 address that matters twice over, because Westminster City Council applies the direction unevenly across Westminster — we read the Westminster policies map for the exact NW8 address before quoting wrap around extensions.

Digging below a Westminster property: Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Where a wrap around extension in Westminster involves excavation that is read beside the Party Wall etc. Act 1996, which needs two months notice for a Westminster dig within 3 m of a neighbour, and Westminster City Council expects the NW8 ground conditions addressed in the application.

What Westminster is built from: Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density. Heritage-first planning approach; listed buildings on almost every street; basement and rear extension policies particularly strict. That mix decides the wrap around extension route in Westminster more than the postcode does.

Which neighbouring authorities border Westminster?

• Kensington and Chelsea — cross the Westminster boundary and RBKC Planning takes the wrap around extension instead, applying 38 conservation areas of its own around SW1. We re-price wrap around extensions at the Westminster edge because Kensington and Chelsea policy and Westminster policy rarely align on wrap around extension depth.
• Wandsworth — adjoining Westminster, with 45 conservation areas centred on SW8. A wrap around extension on the far side of the Westminster line is determined by Wandsworth Council, so the Westminster quote for wrap around extensions is checked against Wandsworth guidance before it is issued.
• Lambeth — adjoining Westminster, with 64 conservation areas centred on SE1. A wrap around extension on the far side of the Westminster line is determined by Lambeth Council, so the Westminster quote for wrap around extensions is checked against Lambeth guidance before it is issued.
• City of London — cross the Westminster boundary and City of London Corporation takes the wrap around extension instead, applying 27 conservation areas of its own around EC1. We re-price wrap around extensions at the Westminster edge because City of London policy and Westminster policy rarely align on wrap around extension depth.

Sources for this Westminster wrap around 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.