Lewisham has significant conservation area coverage at 18%, and several streets are covered by design guidance that affects loft conversion applications. Householder approvals in Lewisham run at around 78% with an average decision time of 10 weeks.
A loft conversion in Lewisham 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.
Loft conversions are permitted development for houses (not flats) under GPDO Schedule 2, Part 1, Class B, within strict volume and design limits.
Read the full loft conversion planning guide for the national rules and application process.
The CanUBuild checker surfaces real recent applications close to your address — approvals and refusals — so you can see what the planning officers at Lewisham Council have approved for comparable schemes. Nearby precedent is one of the strongest signals for your own chances.
In Lewisham, the answer depends on whether your property sits in a conservation area (18% 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.
Conservation areas in Lewisham 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 Lewisham Council assess conservation area proposals against the specific character appraisal for the street.
Lewisham Council 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.
In Lewisham, 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.
Address-level constraints and recent decisions around the corner. No drawings needed.