Skip to content
ProjectsCost GuidesGuidesAnswersInsightsAbout
Get a Quote

Richmond upon Thames · London

Full Basement Excavation in Richmond upon Thames

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

TW1TW2TW9TW10TW11KT2
Typical Richmond upon Thames cost
£150k–£350k
Timeline
2228 wks
Build estimator

Get a 60-second estimate

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

Richmond upon Thames

Full Basement Excavation specialists across Richmond upon Thames.

We deliver full basement excavation 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.

Full basement excavation creates a new habitable floor below your existing house. The process: excavate 2.5–3m below the existing floor level, underpin the perimeter walls to the new founding depth, install a new structural slab and retaining walls, waterproof to grade 3 (habitable), and fit out as living space — gym, cinema, guest suite, utility, or any combination. Builderr delivers full basement excavations across London in 22–28 weeks at £150,000–£350,000 fixed-scope.

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

Full Basement Excavation cost in Richmond upon Thames 2026.

ConfigurationCost rangeTimeline
Standard 30–40m² basement under terrace, single room£150,000£220,00022–26 wks
40–55m² basement under terrace, multi-room layout£200,000£280,00024–28 wks
Premium 55–70m² basement with light wells£260,000£350,00026–32 wks
Inner London K&C/Westminster premium spec£320,000£480,00028–36 wks

Local advantage

Eight years of full basement excavation 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

Full Basement Excavation examples.

Finished basement living space in Richmond upon Thames
Basement gym interior in Richmond upon Thames
Excavation work in progress in Richmond upon Thames
Basement open-plan room 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
£250,000
a full basement excavation in Richmond upon Thames · no provisional sums
Typical builder + variations
£300,000
+£50,000 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£362,500
+£112,500 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 £50,000£112,500 on a full basement excavation 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 £250,000.

FAQ

Full Basement Excavation in Richmond upon Thames.

How much does a full basement excavation cost in Richmond upon Thames?+

Full Basement Excavation projects in Richmond upon Thames typically cost £150,000–£350,000. Richmond upon Thames sits across postcodes TW1, TW2, TW9, TW10; local rates align with the wider London market.

Do full basement excavations 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 full basement excavation projects across all Richmond upon Thames postcodes including TW1, TW2, TW9, TW10, TW11, KT2.

How much does a full basement excavation cost in London?+

A typical 30–40m² basement under a London terrace costs £150,000–£220,000 in 2025. Larger basements (40–55m²) £200,000–£280,000. Premium fit-outs in zone 1–2 with light wells £260,000–£350,000. K&C and Westminster premium spec can exceed £480,000.

Is a basement worth it on a London house?+

On a zone 1–3 property where a basement creates significant habitable floor area, ROI is typically positive — a £250,000 basement on a £1.5m house typically adds £350,000–£500,000 in value. Outer London ROI is usually negative — the build cost exceeds value uplift in zones 4–6.

Get a Richmond upon Thames full basement excavation quote.

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