Side extension in Leeds: Planning Permission Guide

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

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Side extensions in Leeds at a glance

84%

approved

£258

application fee

8

weeks typical

Based on 427 decided applications in Leeds over 12 months (359 granted, 68 refused).

Leeds has numerous conservation areas including Headingley, Roundhay, Chapel Allerton, Armley Mills, and around the city centre. Listed buildings are concentrated in the Victorian warehouse and retail heritage of the city centre and around Kirkstall Abbey. The Yorkshire Dales National Park fringe affects some northern parishes, triggering Article 2(3) designated land rules. Flood zones along the Aire are extensive, affecting many city-centre and riverside properties. Article 4 Directions cover parts of Headingley.

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

Recent side extension decisions in Leeds

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

Granted

Certificate of Proposed Lawful Development for partial demolition of existing single storey side aspect and rebuild using brick, replacem…

LS222026-04-13
Granted

Variation of condition 2 (Approved Plans) to previously approved Planning Application 25/03257/FU (Two storey and single storey side exte…

LS192026-04-10
Granted

First floor side extension; porch to front, including steps and ramp; new doors and glazed screen to ground floor in rear elevation; colo…

LS212026-04-10
Granted

Demolition of single storey detached garage to side; construction of new single storey side extension with roof light; rear window/door e…

LS222026-04-08
Granted

Single storey side extension; alterations to rear fenestration, including new sliding doors and new rooflights; enlarged steps to rear.

LS172026-04-07

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.

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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