Dormer in Tower Hamlets: Planning Permission Guide

A guide to dormer extensions in Tower Hamlets — PD rules, costs, and what you need to know.

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Dormers in Tower Hamlets at a glance

£258

application fee

8

weeks typical

Tower Hamlets has conservation areas in Spitalfields, Bow, Limehouse, Wapping, and around the Isle of Dogs. Article 4 Directions restrict alterations to Georgian and Victorian terraces, particularly around Spitalfields and Fournier Street. Listed building density is notably high in Spitalfields and Wapping. Flood zones along the Thames and Lea add restrictions for outbuildings and basement extensions.

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Permitted Development Rules

Class BPart 1

Additions etc to the roof of a dwellinghouse

GPDO 2015, Schedule 2, Part 1, Class B

Dormers are covered by Part 1, Class B of the GPDO alongside other roof additions. They're subject to volume limits and restrictions on which roof slopes they can face.

Key dimension limits

Within 50m³ total roof volumeNot on front roof slopeNot on highway-facing slope in conservation area

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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Which Professionals Do You Need?

Dormer construction involves significant structural work to your roof, so professional design and engineering input is recommended.

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

Architect / designerRecommended

Loft conversions involve structural alterations and Building Regulations requirements that benefit from professional design.

Typical fee: £2,000£5,000 (Plans + Building Regs)

Structural engineerEssential

Loft conversions require structural calculations for floor strengthening, roof alterations, and any steelwork.

Typical fee: £800£2,500

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

In conservation areas, dormers facing a highway are not permitted development. Rear dormers may still be possible if they meet the volume limits.

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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