Complete Flat Renovation in Chelsea: What It Involves and What It Costs (2026)
When a client buys a flat, the works usually have to happen fast, in one go, and before the furniture arrives. This project was exactly that: a complete renovation of a Chelsea flat for a client who had just bought it, taken from tired and dated to a finished home with new joinery, new bathrooms and a herringbone floor throughout. Here is what a full flat renovation involves, how the programme is organised, and what one costs in London in 2026.
The brief: buy, renovate, move in
The client had just completed on the flat and wanted the whole place done before moving in. No living on a building site, no phasing the work room by room. That is the ideal way to renovate a flat, because empty property means trades can overlap: the electrician can be first-fixing the bedrooms while the bathroom is being tanked and the joiner is measuring the alcoves.
The scope covered every room: reception, kitchen area, bedrooms, two bathrooms, hallway, and all the joinery, decoration, flooring, electrics and plumbing in between.
What a complete flat renovation actually includes
- Strip-out: old kitchen, bathrooms, floor coverings, dated joinery and any partitions coming out
- First fix: new wiring and consumer unit, new pipework, any structural alterations, new stud walls
- Plastering: full skim throughout, new cornice and panelling where specified
- Second fix: sanitaryware, kitchen, sockets and switches, lighting, doors and ironmongery
- Joinery: bespoke alcove units, wardrobes, panelling and the banquette seating
- Finishes: tiling, flooring, decoration, mirrors and glazed screens
The joinery is what makes a flat feel finished
In a London flat, floor area is fixed, you cannot extend. The way you gain usable space is with joinery built to the exact dimensions of the room. On this project that meant alcove shelving flanking the fireplace, floor-to-ceiling wardrobes in the bedrooms, a panelled headboard wall, and a banquette bench in the dining area that seats four in a space a table and chairs could not.
Crittall-style screens instead of walls
Two of the internal divisions are glazed steel-look screens rather than solid walls. In a flat with windows on one elevation only, that is often the difference between a dark internal room and a bright one. The glazing borrows daylight from the room next door while still giving separation.
The bathrooms
Both bathrooms are fully tiled in marble, with herringbone-laid tiling in the shower, recessed niches lit from within, and a stone basin on a fitted vanity. The key detail in a flat bathroom is the waterproofing: tanking behind every tiled surface, and careful attention to the waste runs, because a leak in a flat is not just your problem. It is the flat below’s.
Working in a block of flats
A flat renovation has constraints a house does not, and they need planning for before the first tool comes out:
- Freeholder consent (a licence to alter) is usually needed for anything structural, for moving bathrooms or kitchens, and often for changing floor coverings
- Working hours set by the building management, typically 8am, 5pm weekdays, no weekends
- Lift bookings and protection for materials and waste, and floor protection in the common parts
- Acoustic underlay is normally a lease requirement under hard flooring
- Waste removal has to be scheduled, since there is rarely space for a skip
None of that is difficult, but each one adds days if it is discovered mid-project rather than agreed at the start. A builder who works in blocks regularly will raise them at the quote stage.
What a complete flat renovation costs in London (2026)
| Project | 2026 price (excl. VAT) | Typical programme |
|---|---|---|
| One-bed flat, standard specification | £45,000 to £70,000 | 6 to 10 weeks |
| Two-bed flat, standard specification | £65,000 to £95,000 | 8 to 12 weeks |
| Two-bed flat, high specification (as this project) | £95,000 to £160,000 | 12 to 18 weeks |
| Three-bed flat, high specification | £140,000 to £250,000 | 16 to 24 weeks |
| Single bathroom, high specification | £12,000 to £25,000 | 3 to 4 weeks |
| Bespoke joinery (per room) | £3,500 to £12,000 | , |
The spread is mostly specification, not labour: marble instead of ceramic, bespoke joinery instead of flat-pack, and Crittall-style screens instead of stud walls can double the figure for the same floor area. For room-by-room prices see our refurbishment page and the kitchen renovation cost guide.
Five things worth doing on any flat renovation
- Do it before you move in if you possibly can, it is faster, cheaper and far less stressful than living through it
- Sort freeholder consent first, and get it in writing before the strip-out starts
- Rewire and re-pipe while walls are open, going back later means redecorating twice
- Order long-lead items early: stone, bespoke joinery and glazed screens are typically 6 to 10 weeks
- Spend on what you touch daily: taps, door ironmongery, worktops and lighting, rather than on things nobody notices
Bought a flat that needs everything doing?
GSM Builders Ltd carries out complete flat and house renovations across London. Strip-out to final decoration, one team, one written price and a 12-month workmanship warranty. Free site survey and an itemised quote before anything starts.
Frequently asked questions
How much does it cost to fully renovate a flat in London?
In 2026, expect £45,000 to £70,000 for a one-bed to a standard specification and £65,000 to £95,000 for a two-bed. A high-specification renovation with bespoke joinery, marble bathrooms and glazed screens runs £95,000 to £160,000 for a two-bed. Figures exclude VAT.
How long does a complete flat renovation take?
Six to ten weeks for a one-bed, eight to twelve for a two-bed to a standard specification, and twelve to eighteen weeks for a high-specification two-bed. Empty flats are quicker than occupied ones because trades can overlap.
Do I need the freeholder’s permission to renovate a flat?
Usually yes. Most leases require a licence to alter for structural work, moving bathrooms or kitchens, and often for changing floor coverings. Get written consent before the strip-out begins, retrospective consent is much harder and can hold up a future sale.
Should I renovate before moving in?
If you can, yes. An empty flat lets trades overlap, removes the need to protect furniture and work around a household, and typically shortens the programme by several weeks. It usually costs less for the same scope.
Can you do the whole flat, building, electrics, plumbing and joinery?
Yes. GSM Builders Ltd runs the whole project with one team and one point of contact: strip-out, structural work, electrics, plumbing, plastering, bespoke joinery, tiling, flooring and decoration, with certificates issued at the end.
Do you work outside West London?
Our yard is in Hayes and most projects are in Hillingdon, Ealing, Hounslow and Harrow, but we take on full renovations across London. This project was in Chelsea, SW3.
