Single-storey basement cost in Westminster

Which Westminster postcodes does this basement extension cost single service cover?

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

What changes about a basement extension cost single in each part of Westminster?

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

• Westbourne Green (W2, W9) — basement extension cost single work in Westbourne Green means victorian terraces, mansion blocks. Westbourne Green is Victorian terraces and mansion blocks. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged throughout W2. Westminster City Council decides the Westbourne Green application, and Royal Oak anchors the Westbourne Green location plan.
• Maida Vale (W9) — a basement extension cost single in Maida Vale starts from edwardian mansion blocks, victorian villas, and Maida Vale reads as Edwardian mansion blocks, canal-side. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged in W9. Westminster City Council assesses Maida Vale basement extension cost singles against its own Maida Vale character guidance, and the location plan we draw for Maida Vale references Little Venice.
• Mayfair (W1J, W1K) — Georgian listed townhouses, luxury defines Mayfair, where georgian townhouses, listed buildings set what a basement extension cost single can do. Georgian houses here already have a vault and a lower-ground floor across W1J. Any Mayfair basement extension cost single is validated by Westminster City Council, with Berkeley Square the usual Mayfair reference point on the site plan.
• Belgravia (SW1X, SW1W) — a basement extension cost single in Belgravia starts from regency stucco terraces, listed buildings, and Belgravia reads as white stucco Regency terraces. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged in SW1X. Westminster City Council assesses Belgravia basement extension cost singles against its own Belgravia character guidance, and the location plan we draw for Belgravia references Eaton Square.
• Marylebone (W1U, W1G, W1H) — Georgian and Victorian terraces, mansion blocks defines Marylebone, where georgian terraces, edwardian mansion blocks set what a basement extension cost single can do. Georgian houses here already have a vault and a lower-ground floor across W1U. Any Marylebone basement extension cost single is validated by Westminster City Council, with Marylebone High Street the usual Marylebone reference point on the site plan.
• Pimlico (SW1V) — a basement extension cost single in Pimlico starts from regency terraces, post-war estates, and Pimlico reads as Regency stucco terraces, grid plan. Post-war slab foundations make basements here expensive and rarely viable in SW1V. Westminster City Council assesses Pimlico basement extension cost singles against its own Pimlico character guidance, and the location plan we draw for Pimlico references Tate Britain.
• Soho (W1D, W1F) — Georgian fragments, mixed-use defines Soho, where georgian terraces, mixed-use set what a basement extension cost single can do. Georgian houses here already have a vault and a lower-ground floor across W1D. Any Soho basement extension cost single is validated by Westminster City Council, with Soho Square the usual Soho reference point on the site plan.

What local planning policy applies to a basement extension cost single in Westminster?

How designation changes a Westminster basement extension cost single: Westminster City Council maintains 56 conservation areas, including Pimlico, Soho, Covent Garden. Inside any of them a Westminster basement extension cost single 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. Pimlico sets the tone for Westminster casework.

What Article 4 removes near Westminster: Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones. Before pricing a basement extension cost single we check whether the NW8 address is inside the mapped area, because Westminster City Council draws the Westminster boundary street by street rather than across the whole of Westminster.

Westminster below-ground policy: Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Any basement extension cost single in Westminster that goes below existing foundations triggers two months notice under section 6 of the Party Wall etc. Act 1996, and Westminster City Council will want the NW8 ground and groundwater position set out.

The building fabric around Westminster: 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. A basement extension cost single in Westminster is scoped against that stock first.

Who decides a basement extension cost single on the edge of Westminster?

• Kensington and Chelsea — the Kensington and Chelsea boundary runs against Westminster, so a basement extension cost single a street from Westminster is decided by RBKC Planning instead. Kensington and Chelsea runs 38 conservation areas across SW1 and its neighbours, which is why basement extension cost singles priced for Westminster are re-checked against Kensington and Chelsea policy whenever the Westminster address sits on that edge.
• Wandsworth — cross the Westminster boundary and Wandsworth Council takes the basement extension cost single instead, applying 45 conservation areas of its own around SW8. We re-price basement extension cost singles at the Westminster edge because Wandsworth policy and Westminster policy rarely align on basement extension cost single depth.
• Lambeth — the Lambeth boundary runs against Westminster, so a basement extension cost single a street from Westminster is decided by Lambeth Council instead. Lambeth runs 64 conservation areas across SE1 and its neighbours, which is why basement extension cost singles priced for Westminster are re-checked against Lambeth policy whenever the Westminster address sits on that edge.
• City of London — adjoining Westminster, with 27 conservation areas centred on EC1. A basement extension cost single on the far side of the Westminster line is determined by City of London Corporation, so the Westminster quote for basement extension cost singles is checked against City of London guidance before it is issued.

Sources for this Westminster basement extension cost single 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.