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Greenwich · Loft Conversion · 2026

Loft Conversion Planning Permission in Greenwich: 2026 Guide

Greenwich has significant conservation area coverage at 16%, and several streets are covered by design guidance that affects loft conversion applications. Householder approvals in Greenwich run at around 79% with an average decision time of 10 weeks.

Verdict
May be permitted development

A loft conversion in Greenwich can often be permitted development when it stays within size and design limits and no local constraint applies to your address. Always confirm at address level.

Planning Constraints in Greenwich for Loft Conversion

Conservation area coverage
16%
Approval rate (Greenwich)
79%
Avg. decision time
10 weeks
Article 4 directions
1
Maritime Greenwich World Heritage Site
Thames floodplain in northern wards
Numerous conservation areas in Blackheath and Greenwich
Article 4 directions in Greenwich
  • HMO Article 4 in specified wards

Permitted Development Rules

Loft conversions are permitted development for houses (not flats) under GPDO Schedule 2, Part 1, Class B, within strict volume and design limits.

  • Maximum added volume 40 cubic metres for terraced houses, 50 cubic metres for detached and semi-detached.
  • No part of the extension above the highest part of the existing roof.
  • No extensions on the principal elevation fronting a highway.
  • Side-facing windows must be obscure-glazed and non-opening below 1.7m from floor level.
  • Materials must be similar in appearance to the existing house.
  • Hip-to-gable extensions are not permitted in conservation areas.
  • Dormers must be set back at least 20cm from the eaves.

Read the full loft conversion planning guide for the national rules and application process.

Recent Loft Conversion Decisions in Greenwich

The CanUBuild checker surfaces real recent applications close to your address — approvals and refusals — so you can see what the planning officers at Royal Borough of Greenwich 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 loft conversion in Greenwich?

In Greenwich, the answer depends on whether your property sits in a conservation area (16% of the borough), is listed, or falls within an Article 4 direction. Most loft conversion 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 loft conversion in a conservation area in Greenwich?

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

How long does a loft conversion application take to decide in Greenwich?

Royal Borough of Greenwich currently averages around 10 weeks for householder applications. Complex loft conversion 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.

Are rear dormer loft conversions permitted development in Greenwich?

In Greenwich, rear dormer loft conversions on houses are generally permitted development provided the added volume is under 40m³ (terraced) or 50m³ (semi/detached), the dormer is set back from the eaves and the materials match. Hip-to-gable is excluded from PD in the borough's conservation areas.

Next step

Check your specific address in Greenwich

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