Basement in Croydon: Planning Permission Guide
What you need to know about basement extensions in Croydon — planning requirements, costs, and professional guidance.
Check if your basement qualifiesBasements in Croydon at a glance
approved *
application fee
weeks typical
Based on 16 decided applications in Croydon over 12 months (16 granted, 0 refused). * Limited data — treat as indicative.
Croydon is a large and diverse south London borough with conservation areas around Croydon Minster, Addington Village, Coulsdon, South Norwood, and Waddon. The south of the borough borders Green Belt and the Surrey Hills AONB (National Landscape), triggering Article 2(3) designated land rules in the Biggin Hill and Kenley fringe. Article 4 Directions restrict specific rights in some conservation areas including parts of Shirley, Coulsdon, and Upper Norwood. Flood zones apply along the Wandle valley.
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Approval probability, 5 nearest comparables, refusal reasons — for your specific address.
Recent basement decisions in Croydon
The 5 most recent decided applications. Addresses redacted to postcode area.
Merging of existing commercial units at nos. 7 & 9 Godstone Road, Purley into a single Class E unit with associated internal alterations.…
Submission of details pursuant to conditions 5 (CEMP) and 6 (CMS) related to planning permission 21/02912/FUL for the, "Demolition of exi…
Erection of 4-bedroom two storey detached single family dwelling with basement, off street parking, cycle and waste storage, hard and sof…
Demolition of the existing house and erection of new four storey building to contain 19no. flats plus a basement with car parking, all ma…
Details pursuant to condition 6 (Piling Method) of planning permission 21/00173/FUL (allowed on appeal APP/L5240/W/23/3316205) for "Demol…
These are borough-wide. See the 5 nearest to your address.
Get my report — £9Permitted 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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Run our free 2-minute check to see whether your project likely qualifies as permitted development in Croydon. For personalised approval odds and nearby comparables, get the full report above.
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