Bathroom Refurbishment in London: En-Suite, Family Bathroom and Wet Room Guide

London bathroom refurbishments fall into three broad categories: Full strip-out and replacement: removing everything down to the structural shell (floor, walls, ceiling — back to the joists and masonry) and rebuilding the bathroom from scratch. This is the correct approach for any bathroom with suspected or confirmed moisture damage behind the existing finishes; any bathroom where the drainage layout is to be changed; and any bathroom where the room layout is to be reconfigured. Full strip-out allows the contractor to inspect and remedy any substrate issues (rot, damp, inadequate drainage fall) before reinstating the new bathroom. Surface-level replacement: removing sanitaryware, tiles, and existing wall and floor finishes while retaining the existing drainage positions and substrate. This approach is appropriate where: the existing drainage and substrate are in good condition (confirmed by inspection); the layout is not being changed; and the primary purpose is to update the aesthetics. Surface-level replacement is faster (5-8 working days) and cheaper than a full strip-out, but does not address hidden moisture damage. Conversion (creating a new bathroom or en-suite where none existed): creating a new bathroom in an existing bedroom, building an en-suite in a loft conversion, or converting a storage room to a compact WC. This involves new drainage runs to the nearest soil stack, new waterproofing substrate, new M&E, and a full fit-out from a bare room. New bathroom conversions are the most programme-intensive category and the most technically demanding — drainage gradients, ventilation, and waterproofing must all be designed and constructed correctly from the outset.

A professionally executed London bathroom refurbishment — full strip-out category — follows this sequence: Strip-out: remove existing sanitaryware, tiles, wall boarding or plaster, floor finishes, and existing waterproofing. The structural substrate (joists, masonry, concrete floor) is exposed. Inspection: the contractor inspects the substrate for moisture damage, rotten joists (in a first-floor London Victorian terrace bathroom above a timber suspended floor), inadequate drainage falls, and deteriorated plumbing. Any defects found at this stage are remedied before the new bathroom is installed. Drainage: new or adjusted drainage waste pipes (soil stack for WC, 40mm waste pipe for basin, 40mm or 50mm waste pipe for shower or bath) are installed with the correct gradient (1:40-1:80 fall to drain). This is the most critical element — inadequate drainage falls cause blockages and standing water. Plumbing first fix: hot and cold supply pipes positioned to feed the shower valve, bath taps, basin tap, and WC cistern. If thermostatic shower is specified, the plumber confirms the shower valve position and supply pipe sizes before the wall substrate is installed. Substrate: the walls are lined with moisture-resistant substrate (Hardiebacker cement board, Schluter KERDI-BOARD, or similar — not standard plasterboard) and waterproofed with a tanking system (brush-applied tanking slurry to all walls and floor, or a sheet tanking membrane). The floor is typically tanked. En-suite and wet room floors require a falls system (a pre-formed wet room former with fall to the floor drain, or a screeded fall). Tiling: tiles are fixed to the tanked substrate using flexible adhesive (S1 or S2 rated — do not use standard cement adhesive in a wet environment). All grout joints are sealed with flexible grout (colour-matched); all movement joints (at wall/floor junctions and in field tiles) are filled with silicone sealant (not grout). Second fix plumbing: sanitaryware (bath, shower enclosure or wet room screen, WC, basin, basin furniture) installed and connected to waste, overflow, and supply pipes. Shower valve, basin tap, and bath tap fitted. Heated towel rail or radiator fitted and connected to the heating system. Electrical second fix: spotlights (IP65-rated for zones within 600mm of the shower or bath, IP44 minimum for the rest of the room) fitted and circuits connected. Shaving socket (IP44) fitted. Ventilation: extract fan (typically 100mm or 150mm diameter ducted extract fan — confirmed to achieve a minimum air change rate for the room volume) installed and connected to extract ductwork and an external wall/ceiling termination.

A wet room (a fully waterproofed shower area without a shower tray or enclosure — the entire floor is waterproofed and drains to a linear or centre drain in the floor) is an increasingly popular specification in London bathroom refurbishments — particularly in compact en-suites in loft conversions where a separate shower tray and enclosure would consume too much floor area. Key design and installation considerations for a London wet room: Floor structure suitability: a wet room requires a completely flat and structurally stable floor substrate. In a London Victorian terrace, the bathroom floor is typically a timber suspended floor — timber joist floors deflect under load, and deflection in a wet room floor causes tile cracking at the grout joints. Best practice: a new wet room on a timber-joist floor should incorporate a tile-backing board system (Schluter DITRA-HEAT, Wedi Board, or similar) that decouples the tile finish from the substrate and accommodates minor substrate movement without cracking. Falls to drain: the entire wet room floor must fall to the linear or centre drain — typically 1:60 to 1:100 gradient. This requires either a pre-formed wet room former (a factory-profiled board that incorporates the required fall to the drain position) or a sand-cement screed laid to the required fall. The drain position is fixed before the former or screed is installed — changing the drain position after screeding is a significant and expensive remediation. Waterproofing: the entire wet room envelope — all walls to 1.8m minimum height, all floor, and the ceiling of the wet room area — must be fully waterproofed. A brush-applied tanking system (Aquafix, Hydroban, or similar) applied in two coats to all surfaces, with tanking tape at all wall-floor and wall-wall junctions, is the minimum waterproofing standard. Tiling: non-slip floor tiles (slip resistance rating: R11 minimum for a wet room — check the tile manufacturer's slip resistance rating before specifying) with minimum 600mm x 300mm format (a common specification for London wet rooms). Large-format floor tiles (600mm x 600mm and above) are difficult to lay with a fall in a wet room — the required fall means the tile cannot be level and a level floor cannot be achieved across a large tile. 300mm x 600mm or 300mm x 300mm tiles are more appropriate for wet room floors. Screen: a frameless or semi-frameless glass screen (typically 8mm or 10mm toughened safety glass) to contain splash from the shower zone. The screen should cover the shower head zone and return along the wall to contain the spray.

Bathroom refurbishment is one of the areas of residential construction where the quality difference between contractors is most stark — and where poor workmanship has the most severe consequences. What to check when selecting a London bathroom contractor: Specialist experience: ask specifically about their bathroom refurbishment experience — how many wet rooms have they installed? Do they carry out their own waterproofing or subcontract it? Who does their plumbing — do they employ a Gas Safe and experienced plumber, or use a subcontractor? References: ask for at least two references from similar projects — ideally a wet room or en-suite in a London Victorian terrace or loft conversion. Phone references rather than just reading written testimonials. Waterproofing system: ask which tanking system they use and whether they carry out a water test (filling the tanked room with water before tiling to confirm the waterproofing is intact). A contractor who does not test their waterproofing before tiling is a risk. Tile fixing: ask whether they use flexible S1 or S2 adhesive throughout (not standard cement adhesive). Ask how they handle movement joints and silicone sealant application. Trade qualifications: confirm that the plumber is Gas Safe registered (if gas works are involved) and that the electrician is Part P registered. How to avoid the most common London bathroom mistakes: do not use standard plasterboard on bathroom walls — use moisture-resistant cement board substrate only; do not grout wall/floor junctions — fill with silicone; do not use rigid adhesive on wet room floors — use flexible S1/S2 adhesive; always test drainage falls before tiling.

Indicative 2025 costs for bathroom refurbishment in London: Compact en-suite refurbishment (2-2.5m x 1.8m typical en-suite in a loft conversion — WC, shower, basin, full strip-out, new drainage if required): Budget/standard specification: £5,000-£8,500 supply and install. Mid-range specification (good-quality tile, thermostatic shower valve, semi-frameless screen): £8,500-£13,000 supply and install. Premium specification (designer sanitaryware, large-format tile, frameless screen, underfloor heating): £12,000-£20,000 supply and install. Full family bathroom refurbishment (2.1m x 2.8m to 3m x 2m typical London Victorian family bathroom — bath, WC, basin, shower over bath or separate shower, full strip-out): Budget/standard: £7,000-£12,000 supply and install. Mid-range: £12,000-£20,000 supply and install. Premium: £18,000-£35,000 supply and install. Wet room conversion (new wet room in an existing bathroom or en-suite — floor former, full tanking, glass screen, linear drain): Add approximately £2,000-£4,000 to the above costs for the wet room former, tanking system, linear drain, and non-slip floor tile specification compared with a standard shower tray specification. Cloakroom / WC only refurbishment (compact WC, wash basin): £2,500-£6,000. What is typically included in the above costs: all sanitaryware supply and installation; plumbing labour and materials; tiling labour and materials (mid-range tile allowance typically £30-£60/m² supply, plus adhesive and grout); waterproofing substrate and tanking; extract fan; heated towel rail or radiator. What is typically excluded: premium designer tile (over £60/m² supply price — add the premium tile cost difference to the above figures); bespoke shower screen (add £400-£1,200 for frameless or bespoke vs standard semi-frameless); underfloor heating (add £800-£2,000 for electric UFH under floor tiles); specialist finishes (coloured plumbing fixtures, statement brassware — add £500-£3,000 for premium brassware versus standard); access hatch or boxing for waste pipes.