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Merton · London

Hip-to-Gable Loft Conversion in Merton

South-west borough including Wimbledon — premium extensions and full refurbs common.

SW19SW20CR4SM4
Typical Merton cost
£75k–£130k
Timeline
1014 wks
Build estimator

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

Merton

Hip-to-Gable Loft Conversion specialists across Merton.

We deliver hip-to-gable loft conversion projects across the full Merton postcode set — SW19, SW20, CR4, SM4. South-west borough including Wimbledon — premium extensions and full refurbs common.

A hip-to-gable converts the sloping hip on the side of a semi-detached or end-of-terrace house into a vertical brick gable wall. This rebuilds the roof footprint into a simple pitched form that mirrors a mid-terrace, and almost always pairs with a rear dormer to deliver a master suite, two bedrooms, or a bedroom-plus-office layout with full headroom across both. It's the highest-value loft conversion for 1930s and 1950s London semis — the kind that line streets across Barnet, Enfield, Bromley, Croydon, Sutton, Harrow and Ealing.

Every Merton 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

Hip-to-Gable Loft Conversion cost in Merton 2026.

ConfigurationCost rangeTimeline
Hip-to-gable only£65,000£85,0009–11 wks
Hip-to-gable + rear dormer (1 bed + ensuite)£80,000£105,00010–13 wks
Hip-to-gable + L-shape dormer£95,000£125,00012–14 wks
End-terrace hip-to-gable + double dormer£105,000£130,00012–14 wks

Local advantage

Eight years of hip-to-gable loft conversion work in Merton.

Familiarity with Merton'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 Merton work

Hip-to-Gable Loft Conversion examples.

Hip-to-gable loft bedroom in Merton
Loft with rear dormer in Merton
Loft ensuite shower room in Merton
Loft interior with Velux in Merton
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
£102,500
a hip-to-gable loft conversion in Merton · no provisional sums
Typical builder + variations
£123,000
+£20,500 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£148,625
+£46,125 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 £20,500£46,125 on a hip-to-gable loft conversion in Merton.

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 £102,500.

FAQ

Hip-to-Gable Loft Conversion in Merton.

How much does a hip-to-gable loft conversion cost in Merton?+

Hip-to-Gable Loft Conversion projects in Merton typically cost £75,000–£130,000. Merton sits across postcodes SW19, SW20, CR4, SM4; local rates align with the wider London market.

Do hip-to-gable loft conversions in Merton need planning permission?+

South-west borough including Wimbledon — premium extensions and full refurbs common. 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 Merton postcodes?+

Yes — we deliver hip-to-gable loft conversion projects across all Merton postcodes including SW19, SW20, CR4, SM4.

How much does a hip-to-gable loft conversion cost?+

Hip-to-gable with rear dormer runs £80,000–£130,000 fully fitted across most London semis and end-terraces.

Do I need planning permission for hip-to-gable?+

Usually no — hip-to-gable on semis and end-of-terrace falls under permitted development. Corner plots and conservation areas need full planning.

Get a Merton hip-to-gable loft conversion quote.

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