Genuinely fixed-scope, genuinely on time.
We went through six contractors before Builderr. The others all quoted day-rate or with vague provisional sums. Builderr quoted fully itemised, fixed-scope, with variations only by written instruction. Total cost at completion was £4,200 over the original quote — every penny of that was variations we signed for. 14 weeks on site, finished one week early. Site was clean every Friday, weekly progress photo, monthly walkthrough. We've recommended them to three friends already.
Sarah Mitchell
Wandsworth · SW18
Side return kitchen extension + full ground floor reno
The structural detail was meticulous.
Our previous extension had been done by a cowboy and had subsequent settlement issues. We were nervous about doing more work. Builderr's structural engineer came on site twice before quoting, identified the prior issues, and quoted to remediate alongside the loft work. The detailing on the steel pad-stones, the dormer cheek waterproofing, the floor build-up — everything was thought through and documented. 12 weeks, on programme, on budget. Building control sign-off first time. Couldn't be happier.
James & Emily Carter
Hammersmith and Fulham · SW6
L-shape dormer loft conversion with ensuite
Heritage knowledge we couldn't find elsewhere.
Listed building work is a different animal. We interviewed eight contractors; only two understood the conservation officer's requirements and only Builderr had a conservation specialist architect already part of their team. They co-ordinated listed building consent with English Heritage, sourced reclaimed materials matching the original, used lime mortar throughout. The work passed listed building consent inspection without a single comment. Total project £1.85M over 11 months — every milestone hit on programme.
David Thompson
Kensington and Chelsea · SW7
Heritage refurbishment of Grade II listed townhouse
Best decision we made on the whole project.
We very nearly went with a cheaper contractor whose quote was £18k less. Glad we didn't — friend used him on a similar project, ended up paying £35k more in variations and is now mid-dispute over snags. Builderr's quote was higher but it held. Project came in £1,800 under the quoted figure because one variation went our way. Living through 17 weeks of building with two young kids was hard, but their dust separation was excellent — bedroom and main bathroom usable throughout.
6m rear extension + full kitchen install
Got planning approved after another contractor's refusal.
Different contractor submitted a planning application for us that got refused. Builderr's planning lead spent 90 minutes on site, identified what the planning officer had flagged, redesigned the front mansard profile to match the conservation area requirements, resubmitted, got approved. Then built it. The whole thing took 14 months from first call to handover, but the result is exceptional and the planning history is clean. The kind of long view we couldn't find with smaller firms.
Mansard loft on Victorian terrace + interior refurbishment
Project management was the difference.
We've done two renovations before this one — both painful. Builderr's project manager was on site daily, gave us a Friday update every week, kept the trades in sequence, prevented the cost-overrun spiral we'd seen before. 28-week programme; finished week 27. Final invoice matched the contract sum plus six signed variations totalling £14k. Their MVHR install plus insulation upgrade has cut our heating bill by 60% versus the same month last winter. Honestly transformative.
Charlotte Wright
Camden · NW3
Full house renovation, 220m² Edwardian semi
Structural engineering done right.
Two-storey extension over an existing single-storey garage was structurally complex — the original garage couldn't carry the new upper floor. Builderr's structural team designed a new foundation system that worked around the existing structure without full demolition, saving 6 weeks and £35k. The build itself was efficient — 21 weeks for a 48m² extension that delivered a master suite and bathroom upstairs. Senior team responsive throughout, every email replied to within 4 hours.
Robert Liu
Richmond upon Thames · TW10
Double-storey side extension on detached house
Finish quality on par with a £4M new build.
We've recently spent time in a friend's new build by one of the premium London developers, and our kitchen extension by Builderr feels equal quality. The joinery is mitred and routed beautifully, the marble worktop has barely-perceptible joints, the floor levels are perfectly flush across the threshold to the original house. Builderr's in-house joinery team built our island bespoke. We pay attention to detail, and so did they. £165k total, every penny visible.
Olivia Roberts
Wandsworth · SW11
Side return + rear wraparound extension with bespoke kitchen
Small project done with the same care as a big one.
£32k garage conversion isn't a huge project but Builderr treated it the same way they would a £300k extension. Senior PM on site twice during the 6 weeks. Insulation upgrade to current standards. Proper drainage redesign. New consumer unit. Building control sign-off first time. I work from the office every day now and it's transformed how I work from home. The original quote was the final invoice — no variations, no surprises.
Tomek Kowalski
Lewisham · SE12
Garage conversion to home office with ensuite
Sensitive to the heritage context.
Our Georgian terrace is grade-listed, the kitchen was a 1980s mess we'd inherited. Builderr's design team produced a kitchen that respects the period architecture (no anachronistic modern features) but functions perfectly for daily use. The conservation officer specifically complimented the brassware choice and the period-correct cornicing they restored. £48k for the kitchen renovation, 5 weeks on site, handover one day early.
Eleanor Hayes-Brown
Islington · N1
Premium kitchen renovation, Georgian terrace
Tight schedule, perfect execution.
Both bathrooms needed full strip-out and rebuild in 4 weeks while we had a baby due 5 weeks out. Builderr ran two trades simultaneously across both bathrooms, finished in 3.5 weeks, immaculate result. Wet room install with full tanking, marble walls, premium brassware. Total cost £42k, on budget. Their willingness to compress programme for our family situation without compromising quality — really meaningful at a stressful time.
Naomi Adeyemi
Tower Hamlets · E14
Two-bathroom renovation in modern apartment
44 weeks from groundbreak to handover.
Custom new build on an infill plot we'd had planning for. Builderr ran the full project from groundwork through fit-out. Heat pump, MVHR, solar PV with battery, oak triple-glazed windows. NHBC warranty plus EPC band A. Total project £1.4M, on budget within 2% (our variation, not theirs). 44 weeks on site, snagging done in 5 days post-handover. We've been in the house 8 months now and every system works exactly as designed. The single best project decision we made.
George & Helena Larsen
Merton · SW19
New build infill, 195m² family home, Wimbledon
