Building work in Westminster: area guide

Westminster City Council is the planning and building control authority for Westminster, which covers W1, SW1, W2, WC2, NW1, NW8, W9 and W10 and takes in Marylebone, Mayfair, Pimlico, Belgravia, Soho, Paddington and St John's Wood. This is our area guide to building work in the borough; for whole-house refurbishment go to Home renovation in Westminster.

Westminster counts roughly 132,230 homes for Council Tax; 48% are older than 1919, 10% interwar and 40% post-war, with 91% flats and 9% houses. VOA Council Tax stock of properties, March 2025, for all 24 statistical areas in Westminster. Counts rounded by the VOA.

Planning and building control in Westminster

What Westminster City Council publishes about building work in the borough, with each point linked to the council page it comes from:

• There are 56 conservation areas in Westminster, designated by the council for their special architectural and historic interest. westminster.gov.uk
• Westminster's city-wide Basement Development Article 4 Direction came into force on 31 July 2016 and removes permitted development rights for basement development throughout the city. westminster.gov.uk
• Westminster has also removed permitted development rights in eight conservation areas, where planning permission is required for the specified minor alterations. westminster.gov.uk
• The statutory list includes around 11,000 buildings and other structures in Westminster. westminster.gov.uk
• Following a Partial Review, the current version of Westminster's City Plan was adopted by full council on 21 January 2026. westminster.gov.uk
• Westminster City Council runs its own building control service, the District Surveyors Building Control Service, whose schedule of fees and charges took effect on 1 April 2026. westminster.gov.uk
• Westminster City Council accepts building control applications online as full plans, building notice or regularisation. westminster.gov.uk
• Westminster building control aims to contact applicants within 5 weeks with a decision on a full plans application, but says it may take longer. westminster.gov.uk
• Westminster City Plan Policy 50 supports basements only where they do not extend beneath more than 50% of the garden land, with a separate allowance on small sites where the garden is 8m or less at its longest point. westminster.gov.uk

With 91% of Westminster's homes flats, the lease comes first on many jobs. Flats have no householder permitted development, so an extension or most external changes to a flat need planning permission from Westminster City Council as well as the freeholder's consent. The 9% that are houses keep the householder rights within the size limits, and in a conservation area a single-storey rear extension survives unless an Article 4 direction removes it. Taking out a wall or a chimney breast is building regulations work, not planning, unless the building is listed.

Westminster covers W1, W2, SW1, WC2, NW1, NW8, W9 and W10, and the building stock is unlike anywhere else in London: stucco-fronted Regency terraces in Pimlico and Belgravia, Georgian townhouses in Marylebone and Mayfair and red-brick mansion flats around St John's Wood. On VOA figures, flats are the norm. Much of it is listed and more than three quarters of the City sits inside a conservation area, so the question is what you can change behind an elevation that stays exactly as it is.

Working behind protected Westminster facades starts with listed building consent

Listed status is common across Pimlico, Belgravia and much of Mayfair, and it applies to the inside as well as the front. Cornices, panelled doors, shutter boxes and original staircases all form part of what is protected. Listed building consent from Westminster City Council, a separate application from planning permission, comes before any structural alteration job touches them. We build to the consent granted and coordinate with your architect to get there.

In the houses, the front is fixed, so the gains come from the plan. Lower ground floors get reworked into usable rooms, rear closet wings are opened up, and daylight is pulled through from the garden side. Openings go through nine-inch solid brick laid in lime mortar, so they are RSJ installation work: we appoint a structural engineer, build precisely to the beam design produced, and keep everything propped and monitored while the load transfers.

Mansion flats and central London access put the lease first

Most of the work here happens in flats rather than houses. Mansion blocks around Marylebone, Paddington and St John's Wood come with a lease, a managing agent and a schedule of hours. A kitchen renovation or bathroom renovation there turns first on freeholder consent, the shared soil stack and the floor over the flat below, then on getting materials in through a single lift, protecting communal stairs and hallways, and containing dust and noise.

Parking is the other constant. Bays around Soho, Mayfair and the West End are controlled, loading windows are narrow, and a skip needs a permit before it lands. We plan deliveries around those windows, use bagged waste and staged collections where a skip is impractical, and keep the site tight so your neighbours notice as little as possible. Building control is handled for you.

Popular starting points in Westminster: kitchen renovation in Westminster, house extensions across Westminster, builders in London and Renovations That Add Value.