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Hackney · Rear Extension · 2026

Rear Extension Planning Permission in Hackney: 2026 Guide

Hackney has significant conservation area coverage at 32%, and several streets are covered by design guidance that affects rear extension applications. Householder approvals in Hackney run at around 77% with an average decision time of 10 weeks.

Verdict
Depends on constraints

In Hackney, 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 Hackney for Rear Extension

Conservation area coverage
32%
Approval rate (Hackney)
77%
Avg. decision time
10 weeks
Article 4 directions
1
Residential Extensions and Alterations SPD (Dec 2025) applies
Over 30 conservation areas
HMO controls in specified wards
Article 4 directions in Hackney
  • HMO Article 4 in specified wards

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 Hackney

The CanUBuild checker surfaces real recent applications close to your address — approvals and refusals — so you can see what the planning officers at Hackney 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 Hackney?

In Hackney, the answer depends on whether your property sits in a conservation area (32% 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 Hackney?

Conservation areas in Hackney 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 Hackney Council assess conservation area proposals against the specific character appraisal for the street.

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

Hackney Council currently averages around 10 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 Hackney under permitted development?

A single-storey rear extension on a house in Hackney 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 32% of Hackney.

Next step

Check your specific address in Hackney

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