London Refurbishment & Building Contractor
Build.
Improve.
Certify.
One trusted team for every stage of your project — full home refurbishments, kitchens, bathrooms, loft conversions and extensions. A single point of contact, every trade coordinated, finished to a standard you'd put your name to.
Every service
one team.
Refurbishment, structural alteration, energy upgrades and the compliance certificates that go with them — carried out by our own qualified engineers across all 32 London boroughs.
End-to-end renovations, project-managed from first drawing to final handover. Single point of contact, every trade coordinated, finished to a standard we put our name to.
See refurbishment service →Design-led kitchen fit-outs. Plumbing, electrical, tiling and joinery — all in-house, fixed price, on schedule.
Get a kitchen quote →Complete bathroom transformations, from wet rooms to family suites. Specification-grade finishes, every trade ours.
Get a bathroom quote →Velux, dormer, hip-to-gable and mansard conversions. Free structural survey, fixed quote, full project management.
Book a free survey →Single-storey, double-storey, side-return and wraparound extensions. All trades in-house, fully managed end-to-end.
Get an extension quote →Brickwork, garden walls, boundary walls, retaining walls and structural alterations. Matching brickwork sourced. Free survey.
See wall rebuild service →New boiler installation, system upgrades and replacement runs. Gas Safe registered, often delivered as part of a wider refurbishment.
Get a boiler quote →EICR, Gas Safety (CP12) and EPC certificates from one team. Same-day issue, all of London. The compliance run made simple for landlords and sales.
See compliance services →A clear path from
first call to final handover.
We visit, listen and understand the scope, budget and timeline.
A clear specification and a transparent, itemised quote — no surprises.
One point of contact coordinates every trade, on schedule.
Snagged, certified, and finished to a standard we put our name to.
Built on trust. Backed by results.
Every job carried out by accredited, in-house tradespeople. No subcontractor lottery, no surprises mid-project, no finger-pointing — one point of contact, all the way through.
About GMAS GroupOne project manager. One number to call. Every trade coordinated by us, not by you.
Itemised written specification. No "day rates," no creeping scope, no surprise invoices.
Our own electricians, gas engineers, plumbers and builders — accredited, insured, accountable.
Finished to a standard we'd put our name to. Snagged, certified, handed over clean.
Refurbishment & building across
all 32 London boroughs.
Concentrated in west and south-west London — Chelsea, Kensington, Fulham, Chiswick, Wandsworth and the surrounding postcodes — but covering every borough with the same team, same standards.