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Hammersmith and Fulham · London

Rear Extension in Hammersmith and Fulham

Period terraces with strong demand for side return kitchen extensions and lofts.

W6W12W14SW6
Typical Hammersmith and Fulham cost
£50k–£130k
Timeline
1018 wks
Build estimator

Get a 60-second estimate

Indicative range
£45,000£120,000
814 weeks on site

Hammersmith and Fulham

Rear Extension specialists across Hammersmith and Fulham.

We deliver rear extension projects across the full Hammersmith and Fulham postcode set — W6, W12, W14, SW6. Period terraces with strong demand for side return kitchen extensions and lofts.

A rear extension projects from the back of the house into the garden, creating open-plan living, a new kitchen or a family room. Single-storey rears can extend up to 6 metres on detached homes and 8m by prior approval under the Larger Home Extension scheme. They suit terraces, semis and detached houses across London and remain the most popular extension type by volume.

Every Hammersmith and Fulham project includes a free desk-based planning assessment before we quote. We know the local planning officers, party wall surveyors and approved inspectors by name.

Costs

Rear Extension cost in Hammersmith and Fulham 2026.

ConfigurationCost rangeTimeline
Single-storey rear (3m deep)£50,000£75,00010–12 wks
Single-storey rear (5–6m deep)£70,000£100,00012–14 wks
Rear + kitchen install£85,000£120,00013–16 wks
Premium rear (structural glass, Crittall)£105,000£130,00014–18 wks

Local advantage

Eight years of rear extension work in Hammersmith and Fulham.

Familiarity with Hammersmith and Fulham's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 4 postcodes the borough covers.

Recent Hammersmith and Fulham work

Rear Extension examples.

Rear kitchen extension in Hammersmith and Fulham
Open plan dining kitchen in Hammersmith and Fulham
Bifold doors open to garden in Hammersmith and Fulham
Rear extension exterior in Hammersmith and Fulham
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
£90,000
a rear extension in Hammersmith and Fulham · no provisional sums
Typical builder + variations
£108,000
+£18,000 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£130,500
+£40,500 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 £18,000£40,500 on a rear extension in Hammersmith and Fulham.

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 £90,000.

FAQ

Rear Extension in Hammersmith and Fulham.

How much does a rear extension cost in Hammersmith and Fulham?+

Rear Extension projects in Hammersmith and Fulham typically cost £50,000–£130,000. Hammersmith and Fulham sits across postcodes W6, W12, W14, SW6; local rates align with the wider London market.

Do rear extensions in Hammersmith and Fulham need planning permission?+

Period terraces with strong demand for side return kitchen extensions and lofts. We carry out a free desk-based planning assessment for your specific address before quoting, identifying whether permitted development, prior approval, or full planning applies.

Do you work across all Hammersmith and Fulham postcodes?+

Yes — we deliver rear extension projects across all Hammersmith and Fulham postcodes including W6, W12, W14, SW6.

How much does a rear extension cost in London?+

Typically £50,000–£130,000 depending on depth, glazing spec, kitchen inclusion and any structural complications.

Do I need planning permission?+

3m deep and under is permitted development. 3m–6m on a terrace or semi requires prior approval under the Larger Home Extension scheme. Beyond that or in conservation areas, full planning.

Get a Hammersmith and Fulham rear extension quote.

Senior consultant call within one business hour. Fixed-scope quote for your Hammersmith and Fulham project — no provisional sums.