Basement in Southwark: Planning Permission Guide
What you need to know about basement extensions in Southwark — planning requirements, costs, and professional guidance.
Based on 175 decided applications in Southwark over 12 months (174 granted, 1 refused).
Southwark has numerous conservation areas including Borough, Bermondsey, Dulwich Village, Herne Hill, and Peckham Rye. Dulwich Village has a unique Dulwich Estate Scheme of Management layering private controls over standard planning. Article 4 Directions cover many Victorian terraces. Listed buildings are concentrated along the Thames frontage and around Southwark Cathedral. Flood zones apply near the river.
Recent basement decisions in Southwark
The 5 most recent decided applications. Addresses redacted to postcode area.
Details of condition 55 (Piling method and foundation design) for Plot B pursuant to planning permission 24/AP/3718 'Full planning permis…
Details of condition 55 (Archaeological Post-Excavation Assessment) as required by planning permission ref. 22/AP/1602 dated ref. 24/01/2…
Details of Condition 3b (Remediation Strategy) and Condition 24 (Verification Report) pursuant to planning permission 23/AP/0543 'Constru…
Details of Condition 54 'Mechanical Ventilation' required by planning permission ref. 24/AP/3718 'Demolition of all buildings and struct…
Listed Building Consent for internal refurbishment of the public house across ground floor, mezzanine and basement levels, together with …
These are borough-wide. See the 5 nearest to your address.
Check your address freePermitted 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.
Cost per m²
construction rate
Typical total
Based on 25–50 m²
Typically includes
Typically excludes
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.
Get my estimateWhich 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.
Basement projects are complex and require specialist architectural and structural design.
Typical fee: £5,000–£15,000 (Full architectural service)
Basement excavation requires detailed structural engineering for underpinning, retaining walls, and waterproofing.
Typical fee: £2,000–£5,000
Basement excavation almost always triggers the Party Wall Act due to work near neighbouring foundations.
Typical fee: £700–£1,500 (per neighbour)
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.
Get personalised guidanceConservation 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.
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 (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.
Check my propertyFrequently Asked Questions
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