Bathroom Renovation St John's Wood
Bathroom and wet-room refurbishment in St John's Wood, tanked, plumbed and tiled by one team.
- Rated 4.9 from 31 reviews on MyBuilder
- London guide: £6,000 to £20,000+
- 10 to 15 working days on site
- Free design visit, itemised quote
GS Renovation refurbishes bathrooms across St John's Wood, from en-suites in the NW8 mansion flats and blocks where most people live to family bathrooms in its few period houses. We handle the waterproofing, drainage, tiling, heating and fit-out so the bathroom is dry, warm and properly finished.
In St John's Wood, a full bathroom refit typically costs £6,000 to £20,000 or more (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in St John's Wood: we carry the tanking, plumbing and tiling as one contract, with the electrics certified by a registered electrician.
Price guide
| Work | Indicative London range |
|---|---|
| Bathroom renovation, full refit | £6,000 to £20,000+ |
Indicative London ranges (MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Bathroom Renovation Cost.
Quick estimate for St John's Wood
St John's Wood range: choose above
How the job runs
- Free design visit at your St John's Wood home and an itemised quote.
- Strip-out, then first-fix plumbing and electrics.
- Tanking to the wet areas, then tiling.
- Sanitaryware and second fix, with notifiable electrics certified by a registered electrician. Typically 10 to 15 working days on site.
Waterproofing bathrooms in St John's Wood
The bathrooms in a St John's Wood villa or divided house are often tucked into a rear wing or carved out of a former bedroom, where solid walls, timber floors and older drainage make leaks a real risk. We tank and waterproof the wet areas properly before any tile goes down, so moisture cannot track into the structure below. Getting the falls, the drainage and the mechanical ventilation right is what keeps a period bathroom sound.
Walk-in showers and full wet rooms are popular here, but they demand a fully tanked floor and walls and a reliable fall to the drain, especially over a suspended timber floor. We form the substrate, tank it, then tile in stone, porcelain or mosaic and add underfloor heating to counter the chill of a period property. Ventilation is sized to clear moisture so the finish lasts rather than blackening at the edges within a year.
Housing in St John's Wood
Count the homes in St John's Wood and you get about 8,840: 46% built since 1945, 31% between the wars and 23% before 1919, with flats at 90% and houses at 10%. Where most homes are flats, a bathroom in a flat in St John's Wood sits over a neighbour's ceiling, so tanking comes first.
Bathroom extraction in St John's Wood interwar blocks
A new bathroom in a St John's Wood mansion flat has to breathe somewhere. 31% of homes here were built between 1919 and 1939, and in an interwar block the original bathroom may vent through a window onto a lightwell or into a shaft shared with the flats above and below. A modern extract fan pushing into a shared shaft can carry moisture and smells into other flats. The freeholder's agreement and a check of the shaft's condition come before the fan is chosen, and the fan is sized for the route it actually has.
The alternative, a new terminal through the outside wall, meets the conservation area. The St John's Wood designation dates from 1967 and was widened in 1979 and 2007, and inside a Westminster conservation area some external changes need planning permission even though the same change elsewhere would not. A grille on a rear lightwell elevation is a different proposition from one on the street front of a mansion block, so we look for a route to a hidden elevation first and settle the planning position before anything is cored through.
En-suites and wet rooms in NW8
Space is tight in St John's Wood period homes, so we plan bathrooms and en-suites to make the most of an awkward footprint, borrowing from a landing, a closet wing or a chimney recess to fit a shower, basin and WC without it feeling cramped. Careful setting-out of the drainage runs and the layout means the fittings sit where they work, not just where the old pipes happened to run.
In the mansion flats around NW8, a leaking bathroom affects the flat below, so waterproofing, sound insulation and the freeholder's rules on wet works all matter, and the managing agent will usually need to agree the works first. We tank thoroughly, upgrade the drainage and ventilation, and finish with tiling, underfloor heating and the fittings you choose. One team runs the plumbing, electrics and tiling so the bathroom is watertight and complete.
- Shower pumps and pressure improvements where flow is poor
- Complete bathroom design and planning
- Underfloor heating and heated towel rails
VOA Council Tax stock of properties, March 2025, for St John's Wood North and St John's Wood South. Counts rounded by the VOA.
Why St John's Wood Homeowners Choose GS Renovation
St John's Wood homeowners choose GS Renovation because a bathroom in a mansion flat or period home lives or dies on the waterproofing beneath the tiles, and we get that right. With our founder's 30+ years on the tools, we tank, sort drainage and ventilation, handle leasehold wet-works rules, and finish with tiling, underfloor heating and fittings that last.
Saiid did a complete refurbishment of our small bathroom. This involved ripping out the existing bath/shower, basin, toilet, pipework, and tiles and…
George was a great find. The job required re-plastering the walls before fitting acrylic panels. He also re-plumbed the shower waste under the solid…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
FAQ
Frequently Asked Questions about Bathroom Renovation St John's Wood
Can I get a fixed price for bathroom renovation at an NW8 address?
Fixed pricing is the default for bathroom renovation in St John's Wood, not the exception. What prevents it is real uncertainty about the structure at the NW8 address, and then GS Renovation prices the investigation first and the job afterwards, within £6,000 to £20,000 or more (indicative). Once it is done, the build follows its set sequence: the fall to the waste is set and the walls tanked before tiling.
How do you stop leaks when putting a wet room into my St John's Wood home?
The key is proper tanking. In a St John's Wood period house or converted flat the bathroom often sits over a suspended timber floor, so we form a solid substrate, fully waterproof the floor and walls, and build in a reliable fall to the drain before tiling. We also fit adequate mechanical ventilation. Together these keep moisture out of the structure and stop the leaks older period bathrooms are prone to.
How long is a bathroom renovation in a St John's Wood flat?
Expect 10 to 15 working days of site time, the longer end where waste pipes are rerouted or a concrete floor needs levelling. Mansion block restrictions on noisy hours, plus protecting the lift and hallways each morning, can stretch that further. If this is your only bathroom, we aim to leave a usable toilet every evening.
Can the toilet move in my St John's Wood flat bathroom?
Only as far as the shared soil stack allows. The stack usually serves the flats above and below, so it stays where it is. The toilet's large waste pipe needs a steady fall to reach it, and in a concrete-floored block that often means a raised floor or boxing. The freeholder's consent may be needed to alter drainage. If the move is too far, a macerator is the fallback.
Can I have electric underfloor heating on a concrete floor in my St John's Wood flat?
Yes, with insulation board laid first, otherwise much of the heat goes into the slab. The mat sits on the board, then tile adhesive and tiles. It needs a new circuit, which Part P makes notifiable, so a registered electrician installs and certifies it. The floor build-up raises the level slightly, which matters at the door threshold.
Should my St John's Wood flat bathroom run from a combi or a cylinder?
It depends on how many outlets run at once and where a cylinder could fit. A combi gives mains pressure without storage, which suits one bathroom well. Two bathrooms used at once may need an unvented cylinder, which takes cupboard space. Any new boiler flue through the external wall needs the freeholder's consent, and gas work is done by a Gas Safe engineer.
Does a St John's Wood bathroom refit need a building control application?
Where it includes controlled work, such as new drainage, an extract fan to outside or new electrical circuits, yes. Westminster's schedule has a minor works charge for bathroom and kitchen fit outs in a single property, identical on either route. A bathroom created in a new position changes the layout, so under Westminster's rule full plans applies. Swapping sanitaryware on existing pipework is not building work in itself.
What does Westminster need at the end of a St John's Wood bathroom job?
The fees settled and the relevant certificates, because Westminster issues the completion certificate only after all fees due are received and relevant electrical and gas certificates are supplied. A bathroom with a new circuit, electric underfloor heating or a relocated boiler produces one of those certificates. We hand them over at the final inspection. The completion certificate is then kept with the freeholder's licence, since a buyer's solicitor is likely to ask for both.
Does the lease allow a wet room in a St John's Wood mansion flat?
Read it before designing one. With 90% of St John's Wood homes being flats, the lease is the first document for any bathroom. Some leases restrict wet rooms or level-access showers because a failure floods the flat below, and others allow them only with a specified waterproofing system and an inspection. The freeholder's licence then names the system used, which protects you if a leak is later disputed.
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