House Extension Drawings in Lewisham

Which postcode districts around Lewisham do we cover for house extension work?

Every Lewisham postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. Lewisham fees below are the statutory England rates for 2026, not house extension estimates.

What changes about a house extension in each part of Lewisham?

Roof pitch, wall build-up and plot depth change every few Lewisham streets, and each one changes what a house extension can achieve at that address.

• Hither Green (SE13) — Edwardian terraces, 1930s semi-detached defines Hither Green, where edwardian terraces, 1930s semi-detached set what a house extension can do. Edwardian plots here are wider across SE13. Any Hither Green house extension is validated by Lewisham Council, with Mountsfield Park the usual Hither Green reference point on the site plan.
• Sydenham (SE26) — house extension work in Sydenham means victorian villas, edwardian terraces. Sydenham is Victorian villas, Edwardian terraces. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage throughout SE26. Lewisham Council decides the Sydenham application, and Sydenham Wells Park anchors the Sydenham location plan.
• Brockley (SE4) — house extension work in Brockley means victorian and edwardian terraces. Brockley is Victorian and Edwardian terraces. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage throughout SE4. Lewisham Council decides the Brockley application, and Brockley station anchors the Brockley location plan.
• Forest Hill (SE23) — Victorian villas, Edwardian terraces defines Forest Hill, where victorian villas, edwardian terraces set what a house extension can do. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage across SE23. Any Forest Hill house extension is validated by Lewisham Council, with Horniman Museum the usual Forest Hill reference point on the site plan.
• Honor Oak (SE23) — Victorian villas on the hill defines Honor Oak, where victorian villas, edwardian terraces set what a house extension can do. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage across SE23. Any Honor Oak house extension is validated by Lewisham Council, with One Tree Hill the usual Honor Oak reference point on the site plan.
• Lewisham (SE13) — a house extension in Lewisham starts from victorian terraces, post-war flats, and Lewisham reads as Victorian terraces, post-war centre. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage in SE13. Lewisham Council assesses Lewisham house extensions against its own Lewisham character guidance, and the location plan we draw for Lewisham references Lewisham station.
• Blackheath (SE3) — Georgian and Victorian villas around the heath defines Blackheath, where georgian villas, victorian terraces set what a house extension can do. Georgian rear elevations here are usually the listed or locally listed face of the building across SE3. Any Blackheath house extension is validated by Lewisham Council, with Blackheath the usual Blackheath reference point on the site plan.

What local planning policy applies to a house extension in Lewisham?

Lewisham conservation designations: there are 30 across Lewisham Council, Hither Green, Lee Green, Blackheath among them. Designation costs a Lewisham owner the permitted-development route: a house extension then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Deptford High Street is the Lewisham designation that most often changes a house extension design.

Lewisham permitted development status: there is no borough-wide direction from Lewisham Council, so a house extension at a SE4 address is normally still permitted development. We certify that with a £274 Lawful Development Certificate rather than leaving a Lewisham sale to argue it later.

The building fabric around Lewisham: Victorian and Edwardian terraces across Brockley, Honor Oak, Forest Hill; 1930s semi-detached in Catford and Hither Green; post-war mixed in Deptford. Generally permissive planning compared to central boroughs; loft conversions and side-return extensions routinely approved under PD. A house extension in Lewisham is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Lewisham Council.

Who decides a house extension on the edge of Lewisham?

• Southwark — cross the Lewisham boundary and Southwark Council takes the house extension instead, applying 43 conservation areas of its own around SE1. We re-price house extensions at the Lewisham edge because Southwark policy and Lewisham policy rarely align on house extension depth.
• Greenwich — cross the Lewisham boundary and Greenwich Council takes the house extension instead, applying 20 conservation areas of its own around SE3. We re-price house extensions at the Lewisham edge because Greenwich policy and Lewisham policy rarely align on house extension depth.
• Bromley — adjoining Lewisham, with 48 conservation areas centred on BR1. A house extension on the far side of the Lewisham line is determined by Bromley Council, so the Lewisham quote for house extensions is checked against Bromley guidance before it is issued.
• Tower Hamlets — cross the Lewisham boundary and Tower Hamlets Council takes the house extension instead, applying 58 conservation areas of its own around E1. We re-price house extensions at the Lewisham edge because Tower Hamlets policy and Lewisham policy rarely align on house extension depth.

Sources for this Lewisham house extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.