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Camden · London

Side Return Extension in Camden

Conservation-heavy central borough — most loft and extension work requires full planning.

NW1NW3NW5WC1WC2
Typical Camden cost
£55k–£120k
Timeline
1016 wks
Build estimator

Get a 60-second estimate

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

Camden

Side Return Extension specialists across Camden.

We deliver side return extension projects across the full Camden postcode set — NW1, NW3, NW5, WC1, WC2. Conservation-heavy central borough — most loft and extension work requires full planning.

A side return extension fills the narrow alleyway running alongside the rear closet wing on Victorian and Edwardian terraces. By extending out to the boundary wall, the kitchen gains 3–4 metres of additional width and connects to the garden through a glazed rear wall. It's the most common ground-floor extension in London — over 60% of inner-London terraced extensions are side returns — because it unlocks a generous open-plan kitchen-diner without losing garden depth.

Every Camden 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

Side Return Extension cost in Camden 2026.

ConfigurationCost rangeTimeline
Standard side return (3m wide, full glazed rear)£55,000£75,00010–12 wks
Side return with steel beams + roof lantern£70,000£90,00011–14 wks
Side return + kitchen install£85,000£110,00012–15 wks
Premium side return (Crittall, structural glass)£100,000£120,00013–16 wks

Local advantage

Eight years of side return extension work in Camden.

Familiarity with Camden's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 5 postcodes the borough covers.

Recent Camden work

Side Return Extension examples.

Side return kitchen extension in Camden
Bifold doors to garden in Camden
Open plan kitchen island in Camden
Kitchen with roof lantern in Camden
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
£87,500
a side return extension in Camden · no provisional sums
Typical builder + variations
£105,000
+£17,500 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£126,875
+£39,375 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 £17,500£39,375 on a side return extension in Camden.

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 £87,500.

FAQ

Side Return Extension in Camden.

How much does a side return extension cost in Camden?+

Side Return Extension projects in Camden typically cost £55,000–£120,000. Camden sits across postcodes NW1, NW3, NW5, WC1; local rates align with the wider London market.

Do side return extensions in Camden need planning permission?+

Conservation-heavy central borough — most loft and extension work requires full planning. 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 Camden postcodes?+

Yes — we deliver side return extension projects across all Camden postcodes including NW1, NW3, NW5, WC1, WC2.

How much does a side return extension cost in London?+

Typically £55,000–£120,000 depending on size, glazing spec and kitchen inclusion. A 3m × 4m side return without kitchen runs around £60–80k; with premium kitchen and Crittall glazing closer to £110k+.

Do I need planning permission for a side return?+

Most fall under permitted development. Conservation areas and Article 4 zones usually need full planning. We screen this on every quote.

Get a Camden side return extension quote.

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