House Extensions · SE4 Brockley
Lewisham controls the large Brockley conservation area, one of south London's most extensive; the bay-fronted villas are a strong extension market.
This page covers one part of the borough. For the full picture — fees, timelines and the council's current position — read house extensions in Lewisham.
House extensions in Brockley are dominated by single-storey rear and side-return additions on SE4's victorian terraces and bay-fronted villas around brockley, with double-storey and wrap-around schemes where the plot allows. Lewisham Council weighs depth, height and neighbour daylight; many extensions across Brockley, Crofton Park, Honor Oak fringe, Ladywell fringe are Permitted Development, which we confirm with a Lawful Development Certificate before you build.
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for victorian terraces and bay-fronted villas around brockley typical of Brockley.
Across Brockley, Crofton Park, Honor Oak fringe, Ladywell fringe in SE4, the dominant property is victorian terraces and bay-fronted villas around brockley, with conservation streets on the hill and post-war pockets toward crofton park. That stock shapes what house extension drawings looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Lewisham Council judges each on design quality and neighbour impact. We survey the specific Brockley property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SE4 streetscape.
Housing stock in SE4: Victorian terraces and bay-fronted villas around Brockley, with conservation streets on the hill and post-war pockets toward Crofton Park.
Within the district: Brockley, Crofton Park, Honor Oak fringe, Ladywell fringe.
Streets we know in SE4: the Brockley Conservation Area roads (Wickham Road, Tressillian Road), Breakspears Road and the Crofton Park streets. Each road has its own building line, boundary treatment and precedent that Lewisham Council weighs when assessing a house extension drawings scheme.
Conservation areas: Brockley, Crofton Park / Ewhurst. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SE4: Brockley and Crofton Park on the Overground and Thameslink to London Bridge.
Property values: 346 homes changed hands in SE4 during 2025 and the median price was £558,750, about 4% below the previous year. Semi-detached houses across Lewisham had a median of £763,000 from 279 sales; the borough's 50 detached sales came in at £911,250.
Borough character: Generally permissive planning compared to central boroughs; loft conversions and side-return extensions routinely approved under PD.
Measured existing survey, photographic record, Article 4 and conservation check specific to Brockley before we quote.
2–3 design options at concept stage — alternative layouts, glazing, roof forms.
Site location plan, existing and proposed plans, elevations, sections, D&AS where required.
Part L thermal, Part B fire, Part M accessibility, structural strategy.
Steel beam, foundation, lintel design. Chartered engineer sign-off.
Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.
Yes. The bay-fronted villas and terraces around Wickham Road and Tressillian Road suit side-return and rear extensions and loft conversions, but much of SE4 sits in the Brockley conservation area, so changes there need full planning with a Heritage Statement. We design to match the period detailing and submit to Lewisham.
It is one of south London's largest, covering a great many of the Victorian streets around Brockley and Crofton Park, with controls on materials, bays, front gardens and roofscape. We check whether your exact road falls within it, because that decides whether you need full planning rather than a Lawful Development Certificate.
Outside the conservation area, usually yes — a rear dormer or L-shape within the volume allowance, confirmed by a Lawful Development Certificate. Inside the Brockley designation, roof changes need full planning and are assessed on the roofscape impact. We confirm which applies to your road.
With SE4 houses around £700,000-£1m and Overground and Thameslink links to the City, a side-return or loft adds family space worth comfortably above the build and drawing cost. Brockley's strong period character keeps demand high.
Lewisham Council charges its own statutory application fee (currently £548 for a householder planning application, £610 for a full application). We quote the drawings as one fixed price and the free site survey covers every SE4 address.
For a SE4 project across Brockley, Crofton Park, Honor Oak fringe, Ladywell fringe, expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Lewisham Council (8 weeks for a householder application). We carry the Brockley application through every officer query to the decision.
Brockley (SE4) sits primarily in Lewisham, so applications are decided by Lewisham Council. Conservation areas within SE4 include Brockley, Crofton Park / Ewhurst, where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind house extension drawings in Brockley — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Lewisham Council Building Control or an approved inspector. On SE4's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on SE4 homes.
If your site sits close to the edge of the borough, it is worth checking the authority next door. Browse everything we do in SE3, SE6, SE12, SE13, SE23 and SE26.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every SE4 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. SE4 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| SE4 | Brockley | Victorian and Edwardian terraces | A house extension at an SE4 address in Brockley is determined by Lewisham Council under its own Local Plan policies for Brockley. |
| SE6 | Catford / Bellingham | 1930s semi-detached, post-war flats | Adjoining district to SE4, also inside Lewisham for house extension purposes. |
| SE8 | Deptford | Georgian terraces, post-war estates, new-build | Adjoining district to SE4, also inside Lewisham for house extension purposes. |
| SE12 | Lee / Grove Park | mixed stock | Adjoining district to SE4, also inside Lewisham for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few SE4 streets, and each one changes what a house extension can achieve at that address.
How designation changes a SE4 (Brockley) house extension: Lewisham Council maintains 30 conservation areas, including Hither Green, Lee Green, Blackheath. Inside any of them a SE4 (Brockley) house extension cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Deptford High Street sets the tone for SE4 (Brockley) casework.
Article 4 and your SE4 (Brockley) house extension: Lewisham Council has made no borough-wide direction, so permitted development for a house extension in SE4 (Brockley) generally survives outside SE4 (Brockley) conservation areas and listed curtilages. A Lawful Development Certificate at £274 is how a SE4 owner records that a house extension was lawful.
The building fabric around SE4 (Brockley): 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 SE4 (Brockley) 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.
Sources for this SE4 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.
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