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Richmond upon Thames · London

RSJ Installation in Richmond upon Thames

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

TW1TW2TW9TW10TW11KT2
Typical Richmond upon Thames cost
£5k–£14k
Timeline
13 wks
Build estimator

Get a 60-second estimate

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

Richmond upon Thames

RSJ Installation specialists across Richmond upon Thames.

We deliver rsj installation 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.

An RSJ (Rolled Steel Joist) is the standard structural beam used to carry loads across a new opening in a wall — wall removal, kitchen extension opening, double-storey-extension flank beam, or supporting a chimney breast above a removed lower section. Builderr supplies and installs RSJs across London for ground-floor knockthroughs, extension openings and structural reconfigurations. Engineer's calcs, padstone preparation, install, fire protection, building control sign-off — fixed-scope contract under one team.

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

RSJ Installation cost in Richmond upon Thames 2026.

ConfigurationCost rangeTimeline
Single RSJ to ground-floor opening (≤3m span)£4,500£7,5001–2 wks
Standard knockthrough RSJ (3–4m)£6,500£10,5002–3 wks
Large opening twin-RSJ (>4m span)£9,000£14,0002–3 wks
Extension flank beam over bifold (4–5m)£7,500£12,5002–3 wks

Local advantage

Eight years of rsj installation 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

RSJ Installation examples.

Steel RSJ being installed in Richmond upon Thames
Wall opening with new beam in Richmond upon Thames
Open-plan space after RSJ install in Richmond upon Thames
Structural work in progress 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
£9,250
a rsj installation in Richmond upon Thames · no provisional sums
Typical builder + variations
£11,100
+£1,850 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£13,413
+£4,163 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 £1,850£4,163 on a rsj installation 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 £9,250.

FAQ

RSJ Installation in Richmond upon Thames.

How much does a rsj installation cost in Richmond upon Thames?+

RSJ Installation projects in Richmond upon Thames typically cost £5,000–£14,000. Richmond upon Thames sits across postcodes TW1, TW2, TW9, TW10; local rates align with the wider London market.

Do rsj installations 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 rsj installation projects across all Richmond upon Thames postcodes including TW1, TW2, TW9, TW10, TW11, KT2.

How much does an RSJ cost installed in London?+

A standard single RSJ for a domestic knockthrough costs £4,500–£10,500 installed in London 2025 — including engineer's calcs, beam supply, padstones, install, fire protection, building regs and certificate. Wider openings or twin-RSJ installs run £9,000–£14,000+.

How long does it take to install an RSJ?+

1–3 weeks on site for a standard install. Day 1–2: propping. Day 3–5: wall removal and beam install. Day 6–10: fire protection, plaster, decoration. Add 4–8 weeks pre-install for engineer's calcs and building regs approval.

Get a Richmond upon Thames rsj installation quote.

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