House Extensions · SW13 Barnes
Richmond controls Barnes's extensive conservation areas and the Thames frontage; SW13 is an affluent, tightly protected village market.
The borough-level guide to house extensions in Richmond upon Thames sets out how the same work is handled across the rest of the authority.
House extensions in Barnes are dominated by single-storey rear and side-return additions on SW13's victorian and edwardian terraces and large detached, with double-storey and wrap-around schemes where the plot allows. Richmond Council weighs depth, height and neighbour daylight; many extensions across Barnes, Barnes Village, Castelnau, Little Chelsea 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 large detached typical of Barnes.
Across Barnes, Barnes Village, Castelnau, Little Chelsea in SW13, the dominant property is victorian and edwardian terraces and large detached houses around barnes, with riverside houses along the thames and the barnes village core. 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 Richmond Council judges each on design quality and neighbour impact. We survey the specific Barnes property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SW13 streetscape.
Housing stock in SW13: Victorian and Edwardian terraces and large detached houses around Barnes, with riverside houses along the Thames and the Barnes village core.
Within the district: Barnes, Barnes Village, Castelnau, Little Chelsea.
Streets we know in SW13: the Castelnau villas, the Barnes village streets, Lonsdale Road riverside and the Westmoreland Road terraces. Each road has its own building line, boundary treatment and precedent that Richmond Council weighs when assessing a house extension drawings scheme.
Conservation areas: Barnes Green, Castelnau, Barnes riverside, The Terrace. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SW13: Barnes and Barnes Bridge rail to Waterloo, plus the river and bus links to Hammersmith.
Property values: around £600,000 for a flat and £1.3m-£2.5m for a house — a useful gauge of the build value an extension or loft adds in SW13.
Borough character: Highest conservation area coverage in London; Royal Parks and Thames corridor add heritage layers; design quality heavily scrutinised.
Measured existing survey, photographic record, Article 4 and conservation check specific to Barnes 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.
Strongly. The Barnes Green, Castelnau and riverside conservation areas, with many attractive period houses and a protected village character, mean external changes need full planning with a Heritage Statement, and Richmond scrutinises materials, boundaries and roofscape closely. We design to that standard for SW13 addresses.
Yes. The Thames frontage along Lonsdale Road and The Terrace sits in the flood zone, so riverside extensions and basements need a flood-risk assessment alongside conservation-area planning. We design within those constraints and produce the survey and heritage drawings required.
Yes. The substantial Castelnau villas suit rear and side extensions and the occasional basement, but they sit in a conservation area, so schemes are designed to match the Italianate detailing and submitted by full planning with a Heritage Statement. We coordinate any structural calculations for the larger schemes.
With SW13 houses around £1.3m-£2.5m, a well-designed extension or loft adds floor area worth well above the build and drawing cost, and Barnes's village appeal keeps demand high. A carefully detailed, conservation-compliant scheme protects both approval and resale.
With Barnes property at around £600,000 for a flat and £1.3m-£2.5m for a house, the professional drawing fee is a small fraction of the value the work adds to SW13's victorian and edwardian terraces and large detached. Richmond Council charges its own statutory application fee on top (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 SW13 address.
For a SW13 project across Barnes, Barnes Village, Castelnau, Little Chelsea, 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 Richmond Council (8 weeks for a householder application). We carry the Barnes application through every officer query to the decision.
Barnes (SW13) sits primarily in Richmond upon Thames, so applications are decided by Richmond Council. Conservation areas within SW13 include Barnes Green, Castelnau, Barnes riverside, The Terrace, 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 Barnes — 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 Richmond Council Building Control or an approved inspector. On SW13'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. With Barnes (SW13) property at around £600, 000 for a flat and £1.3m-£2.5m for a house, a well-designed extension or loft typically returns more than it costs in added floor area and sale value. 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 SW13 homes.
Planning history and precedent stop at the borough line, so the comparable approvals nearby may sit elsewhere. See all services in SW14, TW1, TW2, TW9, TW10, TW11 and TW12.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every SW13 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. SW13 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| SW13 | Barnes | Georgian villas, Edwardian terraces | A house extension at an SW13 address in Barnes is determined by Richmond Council under its own Local Plan policies for Barnes. |
| SW14 | Mortlake / East Sheen | Edwardian villas, 1930s semi-detached | Adjoining district to SW13, also inside Richmond upon Thames for house extension purposes. |
| TW1 | Twickenham | Georgian fragments, Victorian terraces, Edwardian villas | Adjoining district to SW13, also inside Richmond upon Thames for house extension purposes. |
| TW2 | Twickenham / Whitton | Georgian fragments, Victorian terraces, Edwardian villas | Adjoining district to SW13, also inside Richmond upon Thames for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few SW13 streets, and each one changes what a house extension can achieve at that address.
SW13 (Barnes) conservation designations: there are 72 across Richmond Council, Barnes Village, Ham Common, Richmond Green among them. Designation costs a SW13 (Barnes) 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. Ham Common is the SW13 (Barnes) designation that most often changes a house extension design.
No blanket Article 4 over SW13 (Barnes): Richmond Council has not withdrawn permitted development across SW13 (Barnes), so a house extension outside a SW13 (Barnes) conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a SW13 owner wants on file.
The building fabric around SW13 (Barnes): Georgian in Richmond Green and Twickenham; Edwardian villas in Barnes and East Sheen; 1930s semi-detached in Whitton; riverside cottages along the Thames. Highest conservation area coverage in London; Royal Parks and Thames corridor add heritage layers; design quality heavily scrutinised. A house extension in SW13 (Barnes) 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 Richmond Council.
Sources for this SW13 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, it is worth understanding what it costs and seeing why homeowners choose us. You can search the site 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.
