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Richmond upon Thames · London

Rear Extension in Richmond upon Thames

Affluent south-west borough — premium kitchen extensions and full renovations dominate.

TW1TW2TW9TW10TW11KT2
Typical Richmond upon Thames cost
£50k–£130k
Timeline
1018 wks
Build estimator

Get a 60-second estimate

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

Richmond upon Thames

Rear Extension specialists across Richmond upon Thames.

We deliver rear extension projects across the full Richmond upon Thames postcode set — TW1, TW2, TW9, TW10, TW11, KT2. Affluent south-west borough — premium kitchen extensions and full renovations dominate.

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 Richmond upon Thames 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 Richmond upon Thames 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 Richmond upon Thames.

Familiarity with Richmond upon Thames's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 6 postcodes the borough covers.

Recent Richmond upon Thames work

Rear Extension examples.

Rear kitchen extension in Richmond upon Thames
Open plan dining kitchen in Richmond upon Thames
Bifold doors open to garden in Richmond upon Thames
Rear extension exterior in Richmond upon Thames
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 Richmond upon Thames · 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 Richmond upon Thames.

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 Richmond upon Thames.

How much does a rear extension cost in Richmond upon Thames?+

Rear Extension projects in Richmond upon Thames typically cost £50,000–£130,000. Richmond upon Thames sits across postcodes TW1, TW2, TW9, TW10; local rates align with the wider London market.

Do rear extensions in Richmond upon Thames need planning permission?+

Affluent south-west borough — premium kitchen extensions and full renovations dominate. 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 Richmond upon Thames postcodes?+

Yes — we deliver rear extension projects across all Richmond upon Thames postcodes including TW1, TW2, TW9, TW10, TW11, KT2.

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 Richmond upon Thames rear extension quote.

Senior consultant call within one business hour. Fixed-scope quote for your Richmond upon Thames project — no provisional sums.