Skip to content
ProjectsCost GuidesGuidesAnswersInsightsAbout
Get a Quote

SW11 · SW12 · SW15 · SW17

BuilderrinWandsworth.

Premium south-west borough including Clapham and Putney — extension and loft hotspot.

Quick answer

Builderr has delivered loft conversions, side return extensions, double-storey rear extensions and full renovations across Wandsworth since 2022 — SW11, SW12, SW15, SW17 and SW18. The borough's Victorian and Edwardian terraced stock across Clapham, Battersea, Balham, Putney, Tooting and Wandsworth Town is prime side-return and L-shape loft territory. Most central streets sit within conservation areas requiring full planning; our team holds a 90% first-time planning approval rate across the borough.

About the area

Local context for Wandsworth builds.

Wandsworth covers postcodes SW11, SW12, SW15, SW17, SW18. We've delivered residential construction projects across nearly every street here since 2022 — loft conversions, side-return and rear extensions, double-storey extensions, kitchen and bathroom renovations, full whole-house refurbishments, and a small number of new-build infill homes.

Premium south-west borough including Clapham and Putney — extension and loft hotspot. Our local project manager for this borough has detailed knowledge of the planning department's preferences, the conservation area boundaries, the common construction details for the prevailing housing stock, and which side streets accept skip permits without issue.

Quotes for Wandsworth projects are fixed-scope after a site survey, valid for 60 days, and never carry provisional sums or open-ended day rates. Every project includes our 10-year structural warranty and 12-month defects period.

Build types in Wandsworth

Specialised types popular here.

Dormer Loft Conversion
Dormer Loft Conversion in Wandsworth

The London standard. Rear dormers add a full-height bedroom + ensuite under permitted development on most terraces.

Mansard Loft Conversion
Mansard Loft Conversion in Wandsworth

The premium loft. Vertical rear wall + 70-degree slate roof. Maximum floor area on Georgian and Victorian terraces.

Hip-to-Gable Loft Conversion
Hip-to-Gable Loft Conversion in Wandsworth

The semi-detached upgrade. Replace the hipped side roof with a vertical gable wall to unlock a full dormer behind.

L-Shape Loft Conversion
L-Shape Loft Conversion in Wandsworth

The Victorian terrace specialist. Build a dormer over both the main roof and the rear closet wing for two bedrooms + bathroom.

Velux Loft Conversion
Velux Loft Conversion in Wandsworth

The cheapest, fastest loft. Insulate the existing roof, install rooflights, and add a fire-rated stair — no roof alteration.

Side Return Extension
Side Return Extension in Wandsworth

The classic kitchen-diner extension. Fill the side alley of a Victorian terrace for a 3–4m wider open-plan kitchen.

Rear Extension
Rear Extension in Wandsworth

Extend the back of the house up to 6m under the prior approval route. Open-plan kitchen-diner with garden views.

Wraparound Extension
Wraparound Extension in Wandsworth

Side return + rear extension combined into one L-shape ground floor. Largest single-storey footprint without going double-storey.

Double-Storey Extension
Double-Storey Extension in Wandsworth

Two floors of extension — bigger kitchen below, extra bedroom + bathroom above. The full upsize without moving.

Kitchen Extension
Kitchen Extension in Wandsworth

Extension build plus full kitchen fit-out in one fixed-price project. Open-plan kitchen-diner with bifold doors and roof lantern.

Integral Garage Conversion
Integral Garage Conversion in Wandsworth

Convert an attached garage to a bedroom, office or living room. No new foundations or external walls. From £25,000 in 4–8 weeks.

Detached Garage Conversion
Detached Garage Conversion in Wandsworth

Transform a detached outbuilding into annexe, home office, studio or garden room. Independent from main house, own entrance.

Load-Bearing Wall Removal
Load-Bearing Wall Removal in Wandsworth

Open up your ground floor — steel beam install, structural calcs, building regs and party wall, fixed-scope.

RSJ Installation
RSJ Installation in Wandsworth

Steel beam supply and install for openings, extensions and structural alterations — engineer-signed, building-regs certified.

Underpinning
Underpinning in Wandsworth

Strengthen existing foundations — for subsidence repair, basement excavation or load increase. Engineer-led, building-regs compliant.

Cellar Conversion
Cellar Conversion in Wandsworth

Convert your existing under-house cellar into a habitable home office, utility, gym or guest room — no excavation needed.

Full Basement Excavation
Full Basement Excavation in Wandsworth

Create a new basement under your existing house — full excavation, underpinning, waterproofing and habitable fit-out.

Basement Extension
Basement Extension in Wandsworth

Add basement floor area beyond the existing house footprint — sub-garden excavation with light wells for cinema, gym, spa.

Planning in Wandsworth

Local planning rules and conservation areas.

Wandsworth contains over 40 conservation areas including Clapham Park, Wandsworth Common, Battersea Park, Northcote, Heaver, Magdalen, Putney, Tonsleys and Bellevue. Article 4 directions cover parts of Northcote and Heaver removing PD rights for external alterations. The council's residential design guide pushes mansards over rear dormers in conservation zones and requires detailed visual impact assessments for two-storey rear extensions. Wandsworth offers a paid pre-application advice service with strong recommendation to engage before submission. The borough is one of London's busier planning authorities — typical determination at 10–12 weeks against the 8-week statutory target.

Every quote we issue for Wandsworth includes a free desk-based planning assessment of your specific address — we tell you whether your project is permitted development, prior approval, or full planning before you sign anything. Our planning team handles the full submission including drawings, Design and Access Statements, and pre-application consultation where required.

Compare

Builderr vs other London builders.

The construction industry has a wide distribution of operators. Here's what changes between a directly-employed, fixed-scope outfit and the alternatives.

Builderr fixed price
£120,000
a Wandsworth project · no provisional sums
Typical builder + variations
£144,000
+£24,000 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£174,000
+£54,000 vs Builderr (≈45% overrun)
CriterionBuilderrTypical London builderCowboy outfit
Labour modelDirectly employed team (PAYE)Mixed subcontract gangsDay-rate cash labour
PricingFixed-scope itemised quoteEstimate + provisional sumsVerbal price + variations
Design & engineeringIn-house architect + SEOutsourced, separate billingBuilder draws on the back of an envelope
Planning + LDC handledYes — included in priceOften charged extraBuilder asks you to apply
Party wall surveyorsInstructed by usYour responsibilitySkipped (illegal)
Building controlPlans + site inspections booked by usBuilding Notice routeNot registered
Project managementDedicated PM, weekly photo updatesForeman doubles upOwner-manager juggles 5 jobs
Payment scheduleStage payments against signed-off milestonesWeekly invoicesCash up front
Insurance£10M PL + 10yr structural warranty£2–5M PL onlyNo documented cover
Snags at handover<3 typical20–30 typicalWalk-off mid-job common
Variation creep0% — fixed scope+15–25% over original quote+40%+ regularly
Bottom line

Save £24,000£54,000 on a Wandsworth project.

Industry data (FMB, RICS, Which? Trusted Trader 2024) shows the average London construction project overruns by 18–22% on cost and 25–35% on time. Fixed-scope contracts with a single accountable team eliminate that variance. The savings above assume a typical project at £120,000.

FAQ

Wandsworth questions, answered.

Do you cover all of Wandsworth?+

Yes — every postcode within Wandsworth is within our standard coverage zone. We've delivered projects in nearly every postcode of the borough since 2022.

How do planning rules differ in Wandsworth?+

Wandsworth's planning authority maintains a local plan and conservation area register that differ from the national permitted development baseline. We run a free desk-based planning assessment of your address before quoting so you know whether your project is PD or needs full planning.

How long does a typical Wandsworth project take?+

Bathroom renovations 2–5 weeks, kitchen renovations 3–8 weeks, loft conversions 8–14 weeks, single-storey extensions 10–18 weeks, double-storey or wraparound extensions 16–22 weeks, full house renovations 16–36 weeks. Programme is fixed at contract sign and tracked weekly.

Do you have references in Wandsworth?+

Yes — we maintain a live reference list per borough. We can connect you with two or three completed clients in Wandsworth for an unfiltered conversation about working with us.

Ready to build in Wandsworth?

Senior consultant call within one business hour. Free desk-based planning assessment for SW11, SW12, SW15 and surrounding postcodes.