Basement conversion in Bromley and Bickley

Investigate the structure and ground before design.

Start with the basement conversion brief

Distinguish an existing cellar conversion from excavation for a new basement. Record levels, drainage, access and the adjoining structures, and obtain project-specific ground and structural investigations before relying on a design or budget.

Plan temporary works, waterproofing, ventilation, escape and spoil removal as part of the same brief. Ask Hampstead Chartered Surveyors to assess party-wall matters and Hampstead Architecture & Planning to coordinate the design requirements. An area name alone does not establish ground conditions.

The local building context

Bromley Council’s Urban Design Guide of July 2023 describes Bickley as a predominantly residential suburban area of mainly detached houses, with no clearly defined centre; public open space is limited, but well-spaced houses have large gardens. It describes the conservation area there, listed by the council as Bickley Park and designated on 28 October 1986, as around 90 mainly residential properties, mostly large houses on spacious plots, together with St George’s Church of 1864, and notes good examples of Arts and Crafts buildings, a style mirrored in modern housing throughout Bickley.

The Local Plan’s Bickley Area of Special Residential Character stretches from the railway south of Bickley Park Road north to Chislehurst Road, and from Pines Road east to Station Approach, plus an enclave around Merlewood Drive. It excludes the 1960s redevelopment of the former Bickley Hall and surrounds a conservation area in Woodlands Road. The plan calls its character spacious inter-war development, with large houses in substantial plots beside the conservation areas at Chislehurst and Bickley. The design guide says the Mavelstone Road, Bickley Conservation Area, designated in May 1987, has a strong representation of the Arts and Crafts Movement.

Bromley Town Centre Conservation Area, designated in January 1985, has an appraisal and management plan adopted on 25 June 2025 replacing the 2011 version. Beyond its High Street, Market Square and lower London Road spine, it has homes: North Street, West Street and Queen’s Road contain residential properties, Queen’s Road with pairs of two-storey red brick Victorian houses with canted bay windows. From the Kentish Way junction east to 85 Widmore Road on the north side and 60 on the south, the council wants to keep the character of a residential road with elegant rows of houses on either side.

Local design and consent context

An Area of Special Residential Character is a Local Plan designation, not a conservation area. Policy 44 requires development in one to respect, enhance and strengthen its special and distinctive qualities, and the plan’s guidelines for these areas say backland development will not be permitted, new development must take account of existing front and rear building lines, mature trees and landscaping are to be kept wherever possible, and proposals that significantly increase hard surfacing in front of houses will be resisted unless they come with satisfactory landscaping.

The Bickley ASRC direction, made on 3 March 2021 and sealed on 15 March 2021, was confirmed to come into effect on 15 March 2022. Its schedule removes Part 1 Class AA, the right to add storeys to a house, and Part 20 Classes A and AA to AD, which allow new homes to be built on top of existing buildings; it does not deal with ordinary extensions, and it applies only inside the ASRC boundary. A separate 2023 direction for the Southborough Road, Bickley neighbourhood centre, later modified by the Secretary of State, concerns changing commercial premises into homes; it does not cover houses.

None of the documents on the council’s Article 4 list is named for the Bickley Park, Mavelstone Road, Sundridge Avenue or Bromley Town Centre conservation areas. That is an absence on a list, not proof that no direction touches a given house, so check the council’s map for the address.

Access and site planning

A skip on the public highway needs Bromley’s temporary highway licence, which only skip companies on the council’s register can apply for; it is valid for two weeks, and the council asks you to allow two working days for processing. No licence is needed on a private road where public access is restricted or controlled, but an unadopted road the public can pass along still needs one. For the red routes, the A21, including Kentish Way, and the A232, the council sends enquiries to Transport for London, which licenses skips there, and it grants no parking dispensations on them. Scaffolding or a hoarding on the highway needs consent too; a parking bay suspension needs an application at least three working days before it starts.

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The Bromley and Bickley area guide · Basement conversion across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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