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Lewisham · London

Integral Garage Conversion in Lewisham

Victorian terraces and semis — strong loft conversion and rear extension demand.

SE4SE6SE8SE12SE13SE14SE23SE26
Typical Lewisham cost
£25k–£48k
Timeline
48 wks
Build estimator

Get a 60-second estimate

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

Lewisham

Integral Garage Conversion specialists across Lewisham.

We deliver integral garage conversion projects across the full Lewisham postcode set — SE4, SE6, SE8, SE12, SE13, SE14, SE23, SE26. Victorian terraces and semis — strong loft conversion and rear extension demand.

An integral garage conversion transforms an attached garage into habitable living space — a home office, bedroom, playroom, utility room or annexe. Because the structure already exists (the garage sits within the main house footprint), no new foundations or external walls are needed. The work is primarily insulation, a new floor, boarding, plastering, heating, electrics and a new front opening treatment. It's the fastest and most cost-effective space addition available to London homeowners, and planning permission is almost never required.

Every Lewisham 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

Integral Garage Conversion cost in Lewisham 2026.

ConfigurationCost rangeTimeline
Basic office or playroom£25,000£32,0004–5 wks
Bedroom with ensuite£32,000£40,0005–7 wks
Premium conversion with glazed front£38,000£48,0006–8 wks

Local advantage

Eight years of integral garage conversion work in Lewisham.

Familiarity with Lewisham's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 8 postcodes the borough covers.

Recent Lewisham work

Integral Garage Conversion examples.

Converted garage bedroom in Lewisham
Home office in converted space in Lewisham
Bright interior conversion in Lewisham
Suburban house exterior in Lewisham
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
£36,500
a integral garage conversion in Lewisham · no provisional sums
Typical builder + variations
£43,800
+£7,300 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£52,925
+£16,425 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 £7,300£16,425 on a integral garage conversion in Lewisham.

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 £36,500.

FAQ

Integral Garage Conversion in Lewisham.

How much does a integral garage conversion cost in Lewisham?+

Integral Garage Conversion projects in Lewisham typically cost £25,000–£48,000. Lewisham sits across postcodes SE4, SE6, SE8, SE12; local rates align with the wider London market.

Do integral garage conversions in Lewisham need planning permission?+

Victorian terraces and semis — strong loft conversion and rear extension demand. 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 Lewisham postcodes?+

Yes — we deliver integral garage conversion projects across all Lewisham postcodes including SE4, SE6, SE8, SE12, SE13, SE14, SE23, SE26.

How much does an integral garage conversion cost in London?+

Typically £25,000–£48,000 depending on use, plumbing needs and front opening treatment. A basic office conversion runs around £25–32k; a bedroom with ensuite closer to £35–40k.

Do I need planning permission for a garage conversion?+

Usually no — integral garage conversions are permitted development in most cases. Conservation areas where the garage door is visible from the street may need permission. We screen this on every quote.

Get a Lewisham integral garage conversion quote.

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