Project guidePlanning required

Basement in Lambeth: Planning Permission Guide

What you need to know about basement extensions in Lambeth — planning requirements, costs, and professional guidance.

88%
approved in Lambeth
£548
application fee
8 wks
typical decision
Planning required

Based on 89 decided applications in Lambeth over 12 months (78 granted, 11 refused).

Lambeth has numerous conservation areas including Clapham, Brixton, Herne Hill, Stockwell, and Kennington. The borough has substantial Article 4 coverage restricting external alterations to Victorian and Edwardian terraces, particularly around Clapham and Stockwell. Listed buildings cluster around Kennington Park and Lambeth Palace. The Thames frontage adds flood zone considerations for properties in Vauxhall and Nine Elms.

Council planning portalPre-application advice

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Recent basement decisions in Lambeth

The 5 most recent decided applications. Addresses redacted to postcode area.

Granted

Approval of details pursuant to condition 18 ( Energy and Sustainability Statement) of planning permission 19/02325/FUL (Erection of 4-st…

SE192026-07-30
Granted

Application for Listed Building Consent for internal and external alterations, including the following: Internal Removal of existing box…

SW42026-07-24
Granted

Approval of details pursuant to conditions 4 (Construction Management Plan) and 7 (Basement Impact Assessment) of Planning Permission Ref…

SW42026-07-13
Granted

Approval of details pursuant to condition 7 (Secured by Design) of Planning permission ref: 21/02688/FUL (Demolition of the existing dwel…

SW42026-07-08
Granted

Partial demolition, excavation and retention of 91, 93-95 and 97 Vauxhall Walk, including erection of new upper floors for office use (Cl…

SE112026-07-08

These are borough-wide. See the 5 nearest to your address.

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Permitted Development Rules

Basement excavation requires a full planning application.

Basement excavation does not have permitted development rights under Part 1 of the GPDO. A full planning application is always required.

Typical Costs in London

Basements are among the most expensive home improvement projects. Costs vary enormously depending on depth, ground conditions, and access.

Basement extensionLondon

Cost per m²

£3,500£6,000

construction rate

Typical total

£100,000£250,000

Based on 25–50

Typically includes

ExcavationUnderpinningWaterproofingStructureElectricsPlumbingBasic finishes

Typically excludes

Planning application feeBuilding regs feeStructural engineerParty wall surveyorArchitect fees

Basement projects are complex and costs vary enormously depending on depth, ground conditions, waterproofing, and access. Professional advice is essential.

Get a personalised cost estimate based on your actual basement dimensions.

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Which Professionals Do You Need?

Basement projects are complex and always require specialist professional input — an architect, structural engineer, and usually a party wall surveyor.

You'll need an architect, a structural engineer, and a party wall surveyor for this project.

Architect / designerEssential

Basement projects are complex and require specialist architectural and structural design.

Typical fee: £5,000£15,000 (Full architectural service)

Structural engineerEssential

Basement excavation requires detailed structural engineering for underpinning, retaining walls, and waterproofing.

Typical fee: £2,000£5,000

Party wall surveyorEssential

Basement excavation almost always triggers the Party Wall Act due to work near neighbouring foundations.

Typical fee: £700£1,500 (per neighbour)

Planning consultantNot needed

This guidance is based on a typical semi-detached house with no special constraints. Listed buildings, conservation areas, and attached properties may require additional professional input.

Find out exactly which professionals you need for your basement.

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Conservation Areas & Listed Buildings

In conservation areas, basement applications receive additional scrutiny. The council will consider the impact on neighbouring properties and the character of the area.

Conservation areas

Properties in conservation areas often have reduced permitted development rights. Some project types (like side extensions) lose PD rights entirely. An Article 4 Direction can remove additional PD rights.

Listed buildings

Listed buildings (Grade I, II*, or II) have no permitted development rights at all. Any external alteration requires Listed Building Consent in addition to any planning permission. An architect experienced in heritage work is essential.

Check if your property is in a conservation area or has other planning constraints.

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Frequently Asked Questions

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