Sitting within the SW17 postcode in the London Borough of Wandsworth, Tooting has firmly established itself as one of South West London's most popular and energetic residential neighbourhoods. From the solid Victorian terraces lining Franciscan Road and Broadwater Road, to the Edwardian semis surrounding Tooting Common and the well-kept period streets near Tooting Bec and Tooting Broadway stations, the area combines genuine architectural character with outstanding green space and fast transport connections into central London.
For SW17 homeowners, extending rather than relocating is the most practical and financially sound route to gaining additional space. Tooting's property values have grown consistently, supported by strong school catchments, the appeal of Tooting Common, and reliable Northern line links into the city. A well-designed extension delivers a meaningful improvement to daily living and a reliable return at resale. This guide is written specifically for Tooting homeowners and reflects Buildaway's experience delivering extensions across Wandsworth, combining transparent 2026 pricing, local planning knowledge, and an 18-month labour warranty on every completed build.
How Much Does a House Extension Cost in Tooting (2026)?
Tooting sits in the mid to upper-mid range of South West London's construction market, offering competitive build costs that reflect the quality and scale of SW17's Victorian and Edwardian housing stock. Below are realistic 2026 mid-market figures:
Single-Storey Rear Extension
- Build-only: £2,600 – £3,400 per m²
- Fully finished with kitchen: £3,400 – £4,600 per m²
- Example: 25 m² kitchen-diner = £65,000 – £85,000 build-only or £85,000 – £115,000 turnkey.
Double-Storey Rear Extension
- Build-only: £2,400 – £3,200 per m²
- Fully finished: £3,200 – £4,400 per m²
- Example: 40 m² across two floors = £96,000 – £128,000 build-only or £128,000 – £176,000 turnkey.
Side Return & Wrap-Around Extensions
A consistently popular choice for Tooting's Victorian mid-terrace stock: £2,600 – £3,800 per m², depending on structural requirements, roof specification, and glazing choice.
All figures reflect fully compliant, Building Control certified builds meeting Wandsworth Council's current planning and construction standards.
What Drives the Price Up or Down
- Total floor area — the primary cost variable across all project types; a larger footprint increases structural, insulation, and finishing expenditure proportionally.
- Structural steelwork — load-bearing wall removal is routine across Tooting's Victorian and Edwardian terrace stock and typically adds £3,000–£7,000 to the overall project cost.
- Roof design and specification — flat roofs with quality membranes and rooflights are the most cost-effective solution; pitched or lantern roof designs add cost but meaningfully improve natural light in the extended space.
- Glazing and doors — bi-fold or sliding doors opening onto a rear garden are popular across SW17 and add £4,000–£10,000 depending on opening width and frame specification.
- Conservation area obligations — parts of Tooting, including streets within the Tooting Bec Common and Tooting Graveney conservation zones, are subject to Wandsworth's heritage controls, influencing material choices and design requirements for consent.
- Kitchen and bathroom fit-out — kitchens in the SW17 market typically range from £11,000 to £29,000+; bathrooms from £6,500 to £15,500.
- Heating and mechanical upgrades — Megaflo unvented systems or boiler replacements are commonly required when extensions increase floor area or add new bathrooms: £3,000–£5,500.
- Site access and logistics — residential parking zones, the density of SW17's terrace streets, and the constraints of Tooting's busier roads all contribute to preliminary costs and require thoughtful programme planning.
Planning Permission & Building Control in Tooting
- Permitted Development (PD): Smaller single-storey rear extensions in Tooting may qualify under PD rights, provided they meet Wandsworth's criteria for depth, height, and materials. Properties within conservation areas or those subject to Article 4 Directions require careful individual assessment before PD is assumed.
- Neighbour Consultation Scheme: Extensions beyond standard PD depth limits — up to 6 metres for terraced and semi-detached properties, 8 metres for detached — require formal notification to Wandsworth Council and neighbouring owners before works begin. Buildaway manages this process on your behalf.
- Full Planning Permission: Required for double-storey extensions, proposals with street-facing visibility, front alterations, and all projects falling outside PD thresholds.
- Conservation Areas: The Tooting Bec Common and Tooting Graveney conservation areas, along with other designated zones within SW17, impose material and design controls on extensions. Wandsworth's planning officers assess all proposals within these areas for visual compatibility with the original building and wider streetscape.
- Party Wall Act: The density of terraced and semi-detached housing throughout Tooting means the Party Wall etc. Act 1996 applies to the majority of extension projects in SW17. Written notices must be formally served on all affected adjoining owners before any structural or excavation works commence.
- Building Control: Mandatory for all extension types — covering structural calculations, thermal performance, drainage, fire safety, and electrical compliance. Buildaway coordinates with Wandsworth's building control team and accredited private inspectors as appropriate to each project.
How Long Will It Take?
- Design and planning preparation: 4–10 weeks
- Technical drawings, approvals, and statutory notices: 3–7 weeks
- On-site construction:
- Single-storey: 10–14 weeks
- Double-storey: 14–20 weeks
- Conservation area applications, bespoke glazing, or premium kitchen installations may extend the overall programme by two to four weeks.
Typical Full Project Budget Breakdown (30 m² Double-Storey)
| Element | Typical Cost |
|---|---|
| Core structure & shell | £76,000 – £96,000 |
| Windows / doors / glazing | £5,500 – £11,500 |
| Kitchen supply & fit | £11,000 – £27,000 |
| Bathroom fit-out | £6,500 – £14,500 |
| Heating / boiler / Megaflo | £3,000 – £5,500 |
| Flooring & decorating | £6,500 – £16,000 |
| Professional fees & permissions | £3,500 – £9,000 |
| Total realistic range: | £112,000 – £160,000 |
(Higher-specification finishes, conservation area requirements, or complex groundworks can push costs beyond £192,000.)
Why Tooting Clients Choose Buildaway
- Wandsworth planning knowledge — practical familiarity with Wandsworth Council's planning policies, conservation area guidance, and the Victorian and Edwardian housing stock that defines Tooting's residential character.
- Fully transparent pricing — detailed, itemised quotations broken down by trade and project stage, with no vague allowances or charges introduced once work is underway.
- 18-month labour warranty — delivering greater post-completion assurance to Tooting homeowners than the standard defects liability period offered by most comparable local contractors.
- Fully accredited and insured — Gas Safe registered, NICEIC certified, and carrying comprehensive public liability insurance on every project without exception.
- Complete project management — Buildaway coordinates architects, structural engineers, Party Wall surveyors, and all specialist trades from first consultation through to final Building Control sign-off.