House Extensions · SW16 Streatham
SW16 spans Lambeth and Croydon; Lambeth controls the Telford Park and Leigham Court conservation areas around Streatham.
If your property sits elsewhere in the borough, the borough-wide page for house extensions in Lambeth covers the same service across every ward.
House extensions in Streatham are dominated by single-storey rear and side-return additions on SW16's victorian and edwardian terraces and bay-fronted semis, with double-storey and wrap-around schemes where the plot allows. Lambeth Council weighs depth, height and neighbour daylight; many extensions across Streatham, Norbury, Streatham Hill, Furzedown 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 bay-fronted semis typical of Streatham.
Across Streatham, Norbury, Streatham Hill, Furzedown in SW16, the dominant property is victorian and edwardian terraces and bay-fronted semis, with mansion blocks and larger villas around streatham and norbury. 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 Lambeth Council judges each on design quality and neighbour impact. We survey the specific Streatham property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SW16 streetscape.
Housing stock in SW16: Victorian and Edwardian terraces and bay-fronted semis, with mansion blocks and larger villas around Streatham and Norbury.
Within the district: Streatham, Norbury, Streatham Hill, Furzedown.
Streets we know in SW16: the Streatham Hill and Telford Park roads, Mount Ephraim Lane and the Furzedown streets. Each road has its own building line, boundary treatment and precedent that Lambeth Council weighs when assessing a house extension drawings scheme.
Conservation areas: Telford Park, Streatham Lodge, Leigham Court. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SW16: Streatham, Streatham Hill and Streatham Common rail to Victoria and London Bridge.
Regeneration: Streatham falls within or beside the Streatham town centre regeneration, which shapes local planning policy and design expectations.
Property values: SW16 registered 978 sales in 2025 at a median of £467,500. Lambeth's own terraced median for the year was £880,000 over 751 sales, but the borough reaches a long way north of Streatham and that number should not be read as a house price here. Contains HM Land Registry data (c) Crown copyright and database right 2026
Borough character: Mix of dense Victorian residential and post-war estate; strong conservation area coverage; generally design-led planning decisions.
Measured existing survey, photographic record, Article 4 and conservation check specific to Streatham 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 bay-fronted semis around Telford Park and Furzedown suit side-return and rear extensions plus loft conversions, much of it within Permitted Development outside the conservation areas, confirmed with a Lawful Development Certificate. We confirm the route and draw to Lambeth's checklist.
SW16 straddles the boundary — Streatham and Streatham Hill sit in Lambeth, while Norbury falls into Croydon. The two councils apply different conservation and householder controls, so we confirm your exact authority before quoting and submit accordingly.
Usually yes — a hip-to-gable plus rear dormer on the semis, within the volume allowance and confirmed by a Lawful Development Certificate, provided you're not in the Telford Park or Leigham Court conservation areas. We check the constraints for your road and draw it for Building Control.
With SW16 houses around £700,000-£1m and Streatham's town-centre regeneration improving the area, a well-designed rear extension or loft adds family space worth comfortably above the build and drawing cost.
Lambeth 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 SW16 address.
For a SW16 project across Streatham, Norbury, Streatham Hill, Furzedown, 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 Lambeth Council (8 weeks for a householder application). We carry the Streatham application through every officer query to the decision.
Streatham (SW16) sits primarily in Lambeth, so applications are decided by Lambeth Council. Conservation areas within SW16 include Telford Park, Streatham Lodge, Leigham Court, 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 Streatham — 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 Lambeth Council Building Control or an approved inspector. On SW16'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 SW16 homes.
Moving, or weighing up a site in the next borough along? Here is the complete service list for SE5, SE19, SE21, SE24, SE27, SW2, SW4 and SW9.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every SW16 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. SW16 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| SW16 | Streatham / Norbury | Edwardian terraces, post-war flats | A house extension in Streatham / Norbury may land with Lambeth Council or Wandsworth Council or Merton Council or Croydon Council — SW16 crosses the boundary, and the SW16 policies map decides it street by street. |
| SW16 | Streatham | Edwardian terraces, post-war flats | Streatham sits inside SW16; house extension proposals here are determined by Lambeth Council. |
| SE11 | Kennington / Vauxhall | Georgian terraces, post-war estates | Adjoining district to SW16, also inside Lambeth for house extension purposes. |
| SE24 | Herne Hill | Victorian villas, Edwardian terraces | Adjoining district to SW16, also inside Lambeth for house extension purposes. |
| SE27 | West Norwood / Tulse Hill | Victorian terraces, Edwardian villas | Adjoining district to SW16, also inside Lambeth for house extension purposes. |
| SW2 | Brixton Hill / Tulse Hill | Victorian terraces, post-war estates | Adjoining district to SW16, also inside Lambeth for house extension purposes. |
| SW11 | Battersea / Clapham Junction | Victorian terraces, mansion blocks | Adjoining district to SW16, also inside Wandsworth for house extension purposes. |
| SW12 | Balham | Victorian and Edwardian terraces | Adjoining district to SW16, also inside Wandsworth for house extension purposes. |
| SW15 | Putney / Roehampton | Edwardian terraces, Victorian villas, mansion blocks | Adjoining district to SW16, also inside Wandsworth for house extension purposes. |
| SW17 | Tooting / Earlsfield | Edwardian terraces | Adjoining district to SW16, also inside Wandsworth for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few SW16 streets, and each one changes what a house extension can achieve at that address.
SW16 (Streatham / Norbury) conservation designations: there are 64 across Lambeth Council, Herne Hill, Brixton Road, Kennington among them. Designation costs a SW16 (Streatham / Norbury) 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. Kennington is the SW16 (Streatham / Norbury) designation that most often changes a house extension design.
SW16 (Streatham / Norbury) and Article 4: Borough-wide Article 4 for HMO conversions; plus office-to-residential restrictions. A house extension planned at a SW16 address is checked against that direction first; Lambeth Council publishes the SW16 (Streatham / Norbury) extent, and the SW16 line rarely follows the SW16 (Streatham / Norbury) boundary you would expect.
What SW16 (Streatham / Norbury) is built from: Victorian terraces in Clapham, Brixton, Herne Hill; Edwardian villas; 1930s and post-war estates in parts of Streatham; Georgian in Kennington. Mix of dense Victorian residential and post-war estate; strong conservation area coverage; generally design-led planning decisions. That mix decides the house extension route in SW16 (Streatham / Norbury) more than the postcode does, and it is what a Lambeth Council case officer reads first. A householder application costs £548 paid to Lambeth Council direct, with 8 weeks to a decision once validated.
SW16 (Streatham / Norbury) conservation designations: there are 45 across Wandsworth Council, Wandsworth Common, Clapham Common West, Tonsley among them. Designation costs a SW16 (Streatham / Norbury) 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. Nightingale Triangle is the SW16 (Streatham / Norbury) designation that most often changes a house extension design.
SW16 (Streatham / Norbury) and Article 4: Article 4 for HMO conversions covering the whole borough. A house extension planned at a SW16 address is checked against that direction first; Wandsworth Council publishes the SW16 (Streatham / Norbury) extent, and the SW16 line rarely follows the SW16 (Streatham / Norbury) boundary you would expect.
What SW16 (Streatham / Norbury) is built from: Extensive Victorian terraced streets — the classic London side-return extension opportunity; Edwardian villas around the commons; 1930s semi-detached in Southfields. Family-oriented, high side-return extension and loft conversion rates; planning department experienced with Victorian terrace modifications. That mix decides the house extension route in SW16 (Streatham / Norbury) more than the postcode does, and it is what a Wandsworth Council case officer reads first. A householder application costs £548 paid to Wandsworth Council direct, with 8 weeks to a decision once validated.
Sources for this SW16 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.
Free fixed quote in 60 seconds. MCIAT chartered.
Get my free quote →Or contact us about your project firstBefore you commit, 30% below London architects and seeing why work with us. You can find your service to find the right fit, or create a free account to track your project. When you are ready, get a quote in minutes — most homeowners have a fee in minutes — or contact us for a chat and a chartered technologist will be in touch.
