Basement in Brighton and Hove: Planning Permission Guide

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

Check if your basement qualifies

Basements in Brighton and Hove at a glance

£548

application fee

8

weeks typical

Brighton and Hove includes or borders South Downs National Park — properties in or near those areas are on Article 1(5) land where permitted-development rights are restricted. Brighton and Hove has 32 conservation areas — extensive heritage coverage restricting external alterations across many streets. 1,229 listed buildings recorded.

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Approval probability, 5 nearest comparables, refusal reasons — for your specific address.

Recent basement decisions in Brighton and Hove

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

Granted

Replacement of existing terracotta floor tiles to front step with new checkerboard tiles, replacement of existing front door, installatio…

BN12026-04-28
Granted

New double doors to rear at basement level, revised fenestration, lanscaping and new patio areas to rear garden and internal alterations.

BN12025-12-18
Granted

Creation of a new basement and lightwell including insertion of windows at basement level and associated works.

BN12025-11-25
Withdrawn

Removal of existing access stair to the front elevation and erection of access stair in new location, landscaping alterations to provide …

BN32025-10-22
Granted

Application to vary condition 1 of planning permission BH2024/02026 to permit alterations to design incorporating change to basement loca…

BN32025-06-18

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 South East England

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

Basement extensionSouth East England

Cost per m²

£3,300£5,600

construction rate

Typical total

£88,000£230,000

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.

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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.

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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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