Wet Room vs Bathroom Renovation: Which Is Right for Your London Home

Wet room and standard bathroom renovation: what each actually involves

A standard bathroom renovation, in the sense used throughout this guide, retains a defined wet zone, a bath, a shower tray and enclosure, or both, sitting within an otherwise conventional floor. The floor around that zone is generally flat, finished at a consistent level throughout the room, and the wet zone itself is waterproofed to a recognised standard before tiling. This is the format most London bathrooms are built to, and it covers everything from a budget like-for-like refresh through to a high-specification refit with a walk-in shower enclosure and a freestanding bath, provided the tray or enclosure still defines where the water is contained.

A wet room, sometimes called a tanked wetroom conversion, removes that containment altogether. The entire floor is formed with a fall, usually towards a linear drain along one wall or a point drain roughly central to the shower area, using a tapered screed or a purpose-made tapered former beneath the tiling. The waterproof membrane isn't limited to a zone around the shower, it runs continuously across the whole floor and up the walls to a set height, so there's no single point of containment for the room to rely on, the entire floor is the containment. There's no tray, no step and no upstand, which is what gives a wet room its level, walk-in finish, but it also means every part of the floor build-up and waterproofing has to be right, since there's no secondary line of defence if a detail fails.

In practice, plenty of rooms sit somewhere between the two: a large-format walk-in shower with a low-profile, near-flush tray recessed slightly into the floor gives much of the visual openness of a wet room without needing the whole floor built to fall. That hybrid is often the sensible middle ground where a genuine wet room isn't achievable for the reasons covered next, and it's worth raising as an option at survey stage rather than assuming the choice is strictly one or the other.

The floor build-up constraint: why a wet room isn't right for every room

Forming a floor to fall towards a drain needs extra depth that a flat floor doesn't. A tapered screed or former typically adds tens of millimetres of build-up at its shallowest point, rising further towards the edges of the fall, on top of the waterproof membrane and tile bed above it. That extra depth has to go somewhere, and the two realistic options are raising the finished floor level of the whole room, which creates a step at the door threshold into the hallway or landing, or dropping the structural floor locally to keep the finished level consistent with the rest of the property. Which of these is achievable, and how much room there genuinely is to work with, is the single biggest factor in whether a wet room is realistic for a given bathroom, and it needs checking before a wet room is specified, not discovered once the floor is already opened up.

Ground floor bathrooms sitting on a solid concrete slab are generally the more forgiving case. Where the slab has enough depth, or where there's scope to break out and locally lower a section of it, forming the fall without a noticeable step at the door is usually achievable, and there's no joist structure underneath to worry about weakening. This is the reason wet rooms are so often specified on ground floor extensions and new-build ground floor bathrooms in London: the structure underneath simply gives more room to work with.

Upper floor bathrooms in suspended timber floor construction, which describes the great majority of London's Victorian and Edwardian upstairs bathrooms, are a genuinely different technical situation. Joists can't be notched or dropped arbitrarily to create a recess for a wet room floor without weakening the structure, and there are recognised limits on how much a joist can be notched or drilled depending on its depth and span. Where a deeper recess is needed than a joist can safely accommodate, the alternative is dropping the floor structure itself, which then depends on how much ceiling void exists in the room directly below, whether that's another room in the same property or, in a converted flat, a ceiling shared with the flat below. If there isn't enough void to drop into without reducing head height below to an unacceptable degree, or without disturbing a ceiling that isn't within the scope of the works, a full wet room conversion on that floor genuinely isn't achievable without wider structural changes.

This is a real technical constraint, not a sales caveat, and it's why not every upstairs bathroom in a Victorian terrace can simply become a wet room by changing the floor finish. Where the floor build-up is genuinely tight, a standard renovation with a low-profile or flush shower tray is usually the more realistic route on an upper floor, giving much of the same finished look without needing to touch the structure beneath it.

This is also where the boundary of our own scope sits clearly. We survey the room, take a genuine measurement of the depth available and the joist span and depth involved, and tell you honestly whether a wet room is achievable within that depth or whether it needs the floor structure altering to work. Where joists need notching beyond what's structurally sound, or the floor needs dropping in a way that affects the structure of the room below, that assessment and specification comes from a structural engineer, not from us. We'll flag early in the survey where that's likely to be needed, so it can be built into the programme and budget from the outset rather than surfacing as a delay once floorboards are already up.

Waterproofing and tanking: how the two compare

A standard bathroom renovation is tanked to the zone approach set out in BS 5385: the shower enclosure itself, the floor area immediately around a bath, and a reasonable margin beyond a basin splash zone get a waterproof membrane before tiling, while the rest of the room's floor and walls are finished conventionally without needing the same treatment. This is a well-understood, widely applied standard, and it's proportionate to the actual water exposure those areas see.

A wet room's waterproofing has to go considerably further, because there's no tray or upstand acting as a backstop. The membrane covers the entire floor, not just the shower area, and is dressed up the walls to a set height around the whole room, with particular care taken at the drain itself, where the membrane needs to seal correctly around the gulley or channel without a gap for water to track behind it. Because a wet room floor holds no water back mechanically, the fall and the membrane are doing all the work that a tray would otherwise share, which is why a wet room floor is a genuinely bigger and more exacting waterproofing job than the zoned tanking a standard bathroom needs, not simply a stylistic variation on the same theme.

This is also why testing before tiling matters more on a wet room than on a standard renovation. Flood or pressure testing a wetroom floor, filling it with a set depth of water and leaving it for a defined period while checking below for any sign of a leak, catches a poorly formed fall or a compromised membrane before it's covered in tiles. Correcting a wrong fall or a failed membrane after tiling means lifting the finished floor and starting the build-up again, which is a far more disruptive and costly fix than finding the same problem at test stage. We test wetroom floors and shower waterproofing before tiling wherever practical, for exactly this reason.

Wet room vs bathroom renovation: cost comparison

The table below sets out realistic 2027 London price ranges for both formats, grounded in the same published bathroom renovation figures we quote across our other bathroom guides. A wet room sits at the premium end of the overall bathroom renovation range rather than in a separate price bracket of its own, reflecting the extra floor preparation, whole-floor waterproofing, testing and, in some cases, structural work involved rather than a different category of job entirely.

Which suits which property type

Beyond the floor build-up constraint covered above, a handful of practical factors tend to decide which format actually suits a specific room.

Resale and everyday practicality trade-offs

Where a property has more than one bathroom, converting a spare bathroom or an ensuite to a wet room carries little practical downside, since a bath remains available elsewhere in the property for anyone who wants one. Where a wet room would become the only bathroom in the property, it's worth thinking through who's likely to buy or rent the property in future as much as how it suits the current household, since a meaningful proportion of family buyers still expect at least one bath somewhere in the property, and a home with no bath at all can narrow that pool of interest, even where the wet room itself is finished to a high standard.

Day to day, a wet room's level, step-free floor is genuinely easier to move around in and to keep clean, since there's no tray edge or enclosure frame collecting grime, and it suits anyone thinking ahead to long-term accessibility in the property, whether that's a change in mobility over time or simply not wanting to deal with a shower tray. A standard bathroom with a bath and separate shower gives more flexibility for different household members' preferences day to day, a quick shower for one person and a bath for another, without either being a compromise on the other's needs.

Maintenance: what changes once the room is finished

A standard bathroom's most common point of failure over time is the sealant and grout line where a shower tray or bath meets the surrounding tiling, a joint that flexes slightly every time the room is used and eventually needs resealing, typically every few years, to stop water tracking behind it. A wet room removes that specific joint, since there's no tray edge for a seal to fail at, but in exchange, a larger area of floor is permanently wet in daily use, so grout across the whole floor, and the seal around the linear or point drain specifically, needs the same kind of periodic attention instead. Neither format is maintenance-free, the maintenance simply moves to a different part of the room.

Ventilation matters for both, and arguably more for a wet room, since a larger wet floor area holds more residual moisture after use than a contained shower zone does, and adequate mechanical extraction, required under Building Regulations Part F in any bathroom without an openable window, helps that floor dry out fully between uses rather than staying damp and encouraging mould at grout lines over time.

Getting your bathroom or wet room specified correctly

Whether you're planning a straightforward like-for-like bathroom refresh, converting a spare bathroom into a wet room, or genuinely unsure which format your room's floor structure can support, our bathroom renovation London team surveys the room, measures the floor build-up actually available, and gives you an honest answer on what's achievable before any specification is finalised. Where tiling to falls or large-format wet room tiling is part of the job, our tiling contractors London team works to the same setting-out and waterproofing standards covered in this guide. Get in touch for a survey and a written quote based on what your specific room and floor structure actually allow.