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Tower Hamlets · Rear Extension · 2026

Rear Extension Planning Permission in Tower Hamlets: 2026 Guide

Tower Hamlets has one of London's highest conservation area coverages at 43%, which affects many rear extension proposals. Householder approvals in Tower Hamlets run at around 72% with an average decision time of 11 weeks.

Verdict
Depends on constraints

In Tower Hamlets, whether a rear extension needs planning permission depends on specific constraints — conservation area, Article 4, listed status or flood risk. Check your address to see which apply.

Planning Constraints in Tower Hamlets for Rear Extension

Conservation area coverage
43%
Approval rate (Tower Hamlets)
72%
Avg. decision time
11 weeks
Article 4 directions
1
Dense historic terraces in Spitalfields and Bow
Tall buildings policy around the Isle of Dogs
Listed buildings across the East End
Article 4 directions in Tower Hamlets
  • HMO Article 4 in specified areas

Permitted Development Rules

Rear extensions are permitted development for houses (not flats) within specific size and height limits set by the GPDO, Schedule 2, Part 1, Class A.

  • Single-storey: max 4m deep for detached, 3m for semi or terraced (or up to 8m/6m under the Larger Home Extension prior approval route).
  • Maximum eaves height 3m if within 2m of a boundary.
  • Maximum overall height 4m.
  • Materials must be similar in appearance to the existing house.
  • No part of the extension may extend beyond the principal elevation fronting a highway.
  • Total extended footprint cannot exceed 50% of the original curtilage.
  • Two-storey extensions must be at least 7m from the rear boundary and no higher than the main roof.

Read the full rear extension planning guide for the national rules and application process.

Recent Rear Extension Decisions in Tower Hamlets

The CanUBuild checker surfaces real recent applications close to your address — approvals and refusals — so you can see what the planning officers at Tower Hamlets Council have approved for comparable schemes. Nearby precedent is one of the strongest signals for your own chances.

Frequently Asked Questions

Do I need planning permission for a rear extension in Tower Hamlets?

In Tower Hamlets, the answer depends on whether your property sits in a conservation area (43% of the borough), is listed, or falls within an Article 4 direction. Most rear extension proposals are permitted development for houses when they stay within GPDO limits and no local constraint applies. Check your exact address with the CanUBuild checker before spending on drawings.

Can I build a rear extension in a conservation area in Tower Hamlets?

Conservation areas in Tower Hamlets typically remove several permitted development freedoms. For a rear extension, the Larger Home Extension route and some external alterations do not apply, so a full householder application is usually required. Planning officers at Tower Hamlets Council assess conservation area proposals against the specific character appraisal for the street.

How long does a rear extension application take to decide in Tower Hamlets?

Tower Hamlets Council currently averages around 11 weeks for householder applications. Complex rear extension proposals — particularly those in conservation areas or on listed buildings — can take longer. Prior approval decisions for Larger Home Extensions are typically issued in 42 days.

How big can a rear extension be in Tower Hamlets under permitted development?

A single-storey rear extension on a house in Tower Hamlets can be up to 4m deep (detached) or 3m deep (semi/terraced) under standard PD. The Larger Home Extension prior approval route extends this to 8m and 6m respectively, but is not available in conservation areas — which cover 43% of Tower Hamlets.

Next step

Check your specific address in Tower Hamlets

Address-level constraints and recent decisions around the corner. No drawings needed.