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Croydon · London

Rear Extension in Croydon

South London borough with strong appetite for lofts, extensions and garage conversions.

CR0CR2CR5CR7CR8CR9SE25
Typical Croydon cost
£50k–£130k
Timeline
1018 wks
Build estimator

Get a 60-second estimate

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

Croydon

Rear Extension specialists across Croydon.

We deliver rear extension projects across the full Croydon postcode set — CR0, CR2, CR5, CR7, CR8, CR9, SE25. South London borough with strong appetite for lofts, extensions and garage conversions.

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 Croydon 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 Croydon 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 Croydon.

Familiarity with Croydon's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 7 postcodes the borough covers.

Recent Croydon work

Rear Extension examples.

Rear kitchen extension in Croydon
Open plan dining kitchen in Croydon
Bifold doors open to garden in Croydon
Rear extension exterior in Croydon
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 Croydon · 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 Croydon.

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 Croydon.

How much does a rear extension cost in Croydon?+

Rear Extension projects in Croydon typically cost £50,000–£130,000. Croydon sits across postcodes CR0, CR2, CR5, CR7; local rates align with the wider London market.

Do rear extensions in Croydon need planning permission?+

South London borough with strong appetite for lofts, extensions and garage conversions. 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 Croydon postcodes?+

Yes — we deliver rear extension projects across all Croydon postcodes including CR0, CR2, CR5, CR7, CR8, CR9, SE25.

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 Croydon rear extension quote.

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