House Extensions · SE20 Anerley
Bromley controls SE20's conservation areas around Penge; SE20 is one of south-east London's most affordable period markets.
If your property sits elsewhere in the borough, the borough-wide page for house extensions in Bromley covers the same service across every ward.
House extensions in Anerley are dominated by single-storey rear and side-return additions on SE20's victorian and edwardian terraces and villas around, with double-storey and wrap-around schemes where the plot allows. Bromley Council weighs depth, height and neighbour daylight; many extensions across Penge, Anerley, Crystal Palace Park 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 and edwardian terraces and villas around typical of Anerley.
Across Penge, Anerley, Crystal Palace Park fringe in SE20, the dominant property is victorian and edwardian terraces and villas around penge and anerley, with mansion blocks and post-war pockets near the crystal palace 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 Bromley Council judges each on design quality and neighbour impact. We survey the specific Anerley property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SE20 streetscape.
Housing stock in SE20: Victorian and Edwardian terraces and villas around Penge and Anerley, with mansion blocks and post-war pockets near the Crystal Palace park.
Within the district: Penge, Anerley, Crystal Palace Park fringe.
Streets we know in SE20: the Alexandra Cottages, the Penge High Street area, Maple Road and the Anerley streets. Each road has its own building line, boundary treatment and precedent that Bromley Council weighs when assessing a house extension drawings scheme.
Conservation areas: Alexandra Cottages, Penge High Street, Crystal Palace Park. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SE20: Penge West and Anerley on the Overground, plus Penge East and Kent House rail.
Property values: semi-detached houses across Bromley had a 2025 median of £625,000, and the borough's all-type median was £525,000. Neither is an SE20 number; the district's own median was £420,000.
Borough character: Largest London borough by area; substantial Green Belt; conservation areas in most town centres; generally permissive elsewhere.
Measured existing survey, photographic record, Article 4 and conservation check specific to Anerley 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 Victorian and Edwardian terraces and villas around Maple Road and the Anerley streets suit side-return, rear and loft extensions, much of it within Permitted Development outside the conservation areas, confirmed with a Lawful Development Certificate. We confirm the route and draw to Bromley's checklist.
Alexandra Cottages is a conservation area of distinctive Victorian model-housing with strong uniform character, so external changes there are tightly assessed on materials and form. We design sympathetically and submit a full application with a Heritage Statement where the designation applies.
Usually yes outside the conservation areas — a rear dormer or L-shape within the volume allowance, confirmed by a Lawful Development Certificate. Inside the Alexandra Cottages or Penge High Street designations, roof changes need full planning. We confirm which applies to your road.
The Overground link keeps demand strong.
Bromley 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 SE20 address.
For a SE20 project across Penge, Anerley, Crystal Palace Park 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 Bromley Council (8 weeks for a householder application). We carry the Anerley application through every officer query to the decision.
Anerley (SE20) sits primarily in Bromley, so applications are decided by Bromley Council. Conservation areas within SE20 include Alexandra Cottages, Penge High Street, Crystal Palace Park, 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 Anerley — 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 Bromley Council Building Control or an approved inspector. On SE20'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 SE20 homes.
Working across a borough boundary, or unsure which council will decide your application? Every service we offer is listed for SE9, SE12, SE26, BR1, BR2, BR3, BR6 and BR7.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every SE20 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. SE20 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| SE20 | Anerley / Penge | Victorian and Edwardian terraces | SE20 straddles a boundary: Anerley / Penge addresses fall to Bromley Council or Croydon Council, so confirm which authority validates the house extension before submitting SE20 drawings. |
| SE20 | Penge | Victorian and Edwardian terraces | Penge sits inside SE20; house extension proposals here are determined by Bromley Council. |
| BR1 | Bromley / Bickley | Victorian terraces, Edwardian villas, post-war flats | Adjoining district to SE20, also inside Bromley for house extension purposes. |
| BR2 | Hayes / Keston | Victorian terraces, Edwardian villas, post-war flats | Adjoining district to SE20, also inside Bromley for house extension purposes. |
| BR3 | Beckenham | Edwardian villas, 1930s semi-detached | Adjoining district to SE20, also inside Bromley for house extension purposes. |
| SE19 | Upper Norwood / Crystal Palace | Victorian villas, Edwardian terraces | Adjoining district to SE20, also inside Croydon for house extension purposes. |
| SE25 | South Norwood / Selhurst | Victorian terraces | Adjoining district to SE20, also inside Croydon for house extension purposes. |
| CR0 | Croydon / Addiscombe / Shirley | Edwardian terraces, post-war flats | Adjoining district to SE20, also inside Croydon for house extension purposes. |
| CR2 | South Croydon | mixed stock | Adjoining district to SE20, also inside Croydon for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few SE20 streets, and each one changes what a house extension can achieve at that address.
How designation changes a SE20 (Anerley / Penge) house extension: Bromley Council maintains 48 conservation areas, including Bickley, Bromley Town, Chislehurst. Inside any of them a SE20 (Anerley / Penge) 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. Bromley Town sets the tone for SE20 (Anerley / Penge) casework.
No blanket Article 4 over SE20 (Anerley / Penge): Bromley Council has not withdrawn permitted development across SE20 (Anerley / Penge), so a house extension outside a SE20 (Anerley / Penge) conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a SE20 owner wants on file.
What SE20 (Anerley / Penge) is built from: Large 1930s detached and semi-detached in Chislehurst and Bickley; Edwardian in Beckenham; Victorian in Bromley town; Metropolitan Green Belt covers significant rural-fringe land. Largest London borough by area; substantial Green Belt; conservation areas in most town centres; generally permissive elsewhere. That mix decides the house extension route in SE20 (Anerley / Penge) more than the postcode does, and it is what a Bromley Council case officer reads first. A householder application costs £548 paid to Bromley Council direct, with 8 weeks to a decision once validated.
How designation changes a SE20 (Anerley / Penge) house extension: Croydon Council maintains 24 conservation areas, including Shirley Park, South Norwood, Crystal Palace. Inside any of them a SE20 (Anerley / Penge) 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. South Norwood sets the tone for SE20 (Anerley / Penge) casework.
No blanket Article 4 over SE20 (Anerley / Penge): Croydon Council has not withdrawn permitted development across SE20 (Anerley / Penge), so a house extension outside a SE20 (Anerley / Penge) conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a SE20 owner wants on file.
What SE20 (Anerley / Penge) is built from: Victorian villas in Upper Norwood and Crystal Palace; Edwardian terraces in Thornton Heath and Selhurst; 1930s semi-detached in Purley and Coulsdon; post-war in Croydon central. Large, mixed-density outer borough; permissive in outer areas; heritage controls in conservation pockets; major regeneration in central Croydon. That mix decides the house extension route in SE20 (Anerley / Penge) more than the postcode does, and it is what a Croydon Council case officer reads first. A householder application costs £548 paid to Croydon Council direct, with 8 weeks to a decision once validated.
Sources for this SE20 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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