Side extension in Ealing: Planning Permission Guide

A complete guide to building a side extension in Ealing, covering permitted development rules, costs, and professional requirements.

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Side extensions in Ealing at a glance

89%

approved

£258

application fee

8

weeks typical

Based on 138 decided applications in Ealing over 12 months (123 granted, 15 refused).

Ealing has over 30 conservation areas including Bedford Park — England's first garden suburb, with notoriously strict design controls — plus Ealing Common, Hanwell, Northfields, and Walpole. Listed building density is high in Bedford Park. Article 4 Directions restrict external changes in Bedford Park and other heritage areas, targeting window replacements and external alterations. The council's conservation enforcement is consistently active.

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

Recent side extension decisions in Ealing

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

Granted

Second floor side extension over existing first floor flat roof, subdivision of a residential dwelling (Flat 5) into three residential dw…

W32026-04-01
Permitted Development

Continued use of property as large HMO (Sue Generis) of 10 rooms for up to 10 people; alteration of roof from hip to gable end; rear roof…

W32026-03-19
Granted

Part two, part single storey side/rear wrap-around extension (Following demolition of existing garage)

W52026-03-13
Granted

Single storey side extension (following demolition of existing side extension); alterations to ground floor rear elevation fenestrations

W52026-03-13
Granted

Part two, part single storey side/rear wraparound extension (Following demolition of existing side extension); front porch extension

UB52026-03-06

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

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Permitted Development Rules

Class APart 1

Enlargement, improvement or other alteration of a dwellinghouse

GPDO 2015, Schedule 2, Part 1, Class A

Side extensions are also covered by Part 1, Class A of the GPDO. They must be single storey and cannot exceed half the width of the original house.

Key dimension limits

Max 2.8m width (half of house)Max 4m heightSingle storey only

These are the maximum GPDO limits for a detached house with no constraints. Your actual limits depend on your property type, location, and any planning restrictions.

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Typical Costs in London

Side extension costs in London depend on the width of your side return and the specification of the build.

Single storey side extensionLondon

Cost per m²

£2,000£3,500

construction rate

Typical total

£30,000£55,000

Based on 10–18

Typically includes

FoundationsStructureRoofElectricsPlumbingBasic finishes

Typically excludes

Kitchen fittingPlanning application feeBuilding regs feeParty wall surveyorArchitect fees

Costs vary depending on whether the side return is narrow or full-width.

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Which Professionals Do You Need?

For a side extension, you'll typically need drawings for Building Regulations approval and may need a party wall surveyor if you share a boundary.

You'll need a party wall surveyor for this project.

Architect / designerOptional

A draughtsperson or architectural technician can prepare the plans needed for a single storey extension. A full architect may not be necessary.

Typical fee: £1,500£3,500 (Plans + Building Regs)

Structural engineerRecommended

Single storey extensions typically need structural calculations for any openings in existing walls and for foundations.

Typical fee: £500£1,500

Party wall surveyorEssential

Your semi-detached house shares a boundary with neighbours. Extensions and loft work within 3 metres of a shared wall trigger the Party Wall Act.

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

Side extensions are not permitted development in conservation areas or Areas of Outstanding Natural Beauty. You will need to apply for full planning permission.

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.

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Frequently Asked Questions

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Run our free 2-minute check to see whether your project likely qualifies as permitted development in Ealing. For personalised approval odds and nearby comparables, get the full report above.

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