A compact family bathroom in a London period property, refurbished end-to-end in three weeks. Three pattern languages held together in a single room: a 3D cube-pattern tile in coral, navy and white on the bath wall; a black-and-white encaustic-style floor across the entire room; a striped tile splashback to the vanity. Beneath all of it, a Schluter Ditra-Heat electric underfloor heating system, a full-room tanking specification, and the same seven-stage build sequence we deliver on every premium bathroom regardless of size. What follows is the project, stage by stage.
The brief was a small family bathroom in a London period property, with one casement window, a constrained footprint, and a household that uses it daily. The client was clear on two priorities. The first was visual: a confident geometric palette, dense in pattern but legible at the scale of a small room. The second was engineering: every element of the build to the same standard we deliver on master suites — full-room tanking, a Schluter Ditra-Heat electric underfloor heating system, a concealed thermostatic shower valve, and pressure-tested first and second fix throughout. A smaller room is not a smaller specification. It is the same specification in a smaller space.
The room came back to us as a daily-use bathroom that performs and reads well above its footprint — warm underfoot from the moment the user steps in, with the kind of design density that rewards close looking. What follows is the build, stage by stage, in the order it happened. Seven stages, three weeks on site, the same protective layers and pressure tests as a much larger room.
The room was stripped back completely. Old tile, sanitaryware, vanity, the wall linings and the floor sub-deck all out. What remained was the structural shell: solid masonry side walls in original brick, suspended timber joists across the floor, and a multi-pane casement window with its frosted glazing. This is the layer at which a refurbishment quote becomes accurate — the assumptions in the survey are confirmed or revised against what is actually there. In this room the joists were sound, the masonry was dry, and the existing service runs needed full replacement rather than partial reuse.
Strip-out also confirmed the headroom available for the final floor build-up. A bathroom with electric underfloor heating sits on a stack of layers: tanked sub-floor, decoupling and heating membrane, tile adhesive and tile. Every millimetre matters for the door-threshold transition and the final tile level against the existing floors either side of the bathroom. With the joists exposed, that build-up was measured, the new sub-deck cut to the right thickness, and the door threshold pre-resolved before any service routing was finalised. The whole project sequences cleanly from this point only if the dimensions are written down at strip-out.
First fix is the stage at which the finished bathroom is laid out invisibly — in copper, in PVC, in electrical cable — before anything the client will see is installed. The bath position determined the route of the hot and cold supply. The vanity position fixed the basin trap drop. The shower mixer position set the rough-in box and the routing for the concealed thermostatic valve. The UFH thermostat location determined the floor-probe conduit and the dedicated electrical circuit run to the consumer unit. None of this can be moved later without lifting the tile and breaking out the wall, so all of it was set out on the plan and verified on the wall before the studwork was closed up.
The principal supplies are copper, soldered on the runs that disappear behind the tile and push-fit only on the accessible connections where serviceability matters more than aesthetics. The wastes are solvent-welded PVC, falling at one in forty to the soil stack, with rodding access at every change of direction. The electrical first fix included the UFH supply cable to a dedicated 16-amp circuit, the floor-probe conduit, the shower extract fan duct, the lighting loops for the ceiling pendant and the four downlights, and the supply to the heated towel rail. By the end of first fix every service in the room was in its final position, capped, and ready to disappear behind the wall lining.
Once first fix passes pressure test and the electrical inspection on the rough installation, the room is closed up. The wet-zone walls are lined in moisture-resistant plasterboard rather than standard board — the difference matters where any vapour or splash reaches the substrate, and the cost increment is small enough that we specify it across the entire bathroom rather than only the shower wall. The board is screwed at 150-millimetre centres into the stud frame, with all edges supported and every penetration cut tight rather than oversized and filled.
The plastering itself is a two-coat skim across the closed-up walls, finished smooth and left to dry fully before any subsequent layer goes on. Drying time is non-negotiable: applying a tanking membrane over plaster that has not reached the manufacturer’s specified moisture content is the single most common cause of tanking failure. We allow plaster to dry on its own schedule, not on the programme’s — a few extra days at this stage protects everything that follows.
The photograph shows the room at the end of this stage. Plaster fully applied, walls dry, ready to receive the tanking membrane on the lower walls and across the entire floor. The next photo, by the time it is taken, will be on top of a tanking layer that does not appear here.
Two layers go on the floor in sequence at this stage, and they do two different jobs. First, tanking: a liquid-applied waterproof membrane painted across the entire floor and up the lower walls in two coats, with reinforcing tape over every internal corner and every service penetration. Tanking is the layer that prevents a hairline grout crack twenty years from now becoming a slow leak into the ceiling below. We tank the whole wet area, not only the shower zone — the cost increment is small, the protection is comprehensive, and we have never regretted specifying it.
Second, on top of the cured tanking, comes the electric underfloor heating membrane: a Schluter Ditra-Heat uncoupling mat with integrated cable channels. The red dimpled membrane visible here serves two functions in a single layer. It is an uncoupling membrane — absorbing the small movements of a suspended timber sub-floor that would otherwise crack the tile bed above — and it accepts the serpentine electric heating cable clipped into its dimpled surface at the cable spacing required for the room area. The combined layer is thinner than three separate layers (tanking, uncoupling mat, UFH cable) would deliver, and on a small bathroom every millimetre of build-up height matters for the door threshold.
The heating cable is rated at 150 watts per square metre of installed area, the recommended output for a tiled bathroom. The floor-probe conduit runs in a dedicated channel between two cable loops, terminating at the wall-mounted programmable thermostat. The whole electrical installation is signed off by a Part P certified electrician, and the certificate is included in the project handover. The floor is tested cold, energised briefly, and re-tested under load before the tile goes down on top of it.
The room takes three tile patterns and asks them to read together rather than to compete. A 3D cube-pattern wall tile in coral, navy and white clads the full feature wall behind the bath and the WC — an optical illusion at a distance, a craftsman’s grid up close. A black-and-white encaustic-style floor tile in a geometric medallion pattern runs across the entire floor, including under the bath and the vanity, so the floor reads as a single composed surface rather than as cut sections. And a black-and-white striped tile, set vertically, clads the wall behind the vanity as a splashback that picks up the rhythm of the floor without competing with the feature wall.
Tile setting in a small room is the stage where small errors become visually unavoidable ones. The cube tile has to start from a true horizontal datum across the feature wall — not from the floor, which is rarely flat enough in a London period property to serve as a reference. The floor tile has to set out from the room’s focal points (the doorway and the bath edge) back to the perimeter, so the cut tiles fall against the skirting where they read least. The striped tile has to align its stripes to the vertical grid of the vanity below it. None of this is improvised. It is set out on paper, then dry-laid on the floor, and the cut tile positions are confirmed before a single bag of adhesive is mixed. With three patterns in a small room, set-out is the difference between dense and incoherent.
Fit-out is the stage at which the room moves from a tiled shell to a working bathroom. The order matters. The bath is set first, levelled on its plinth, plumbed in and pressure tested before anything else lands. The dark Shaker vanity is fitted next, levelled, screwed to the wall through a noggin set during first fix, and connected to the second-fix plumbing at the trap and the supplies. The black-framed shower screen is set into the tiled corner with a high-grade silicone designed for movement at the bath rim — a junction that flexes under occupancy and is the most common point of long-term sealant failure if specified poorly. The wall-hung mirror cabinet, the heated towel rail and the WC pan and cistern complete the sanitaryware fit.
The UFH thermostat is fitted at this stage, recessed into the wall on its own back-box at the height specified by the client and within the zone allowed by the electrical regulations for a bathroom (outside Zones 0, 1 and 2). The floor probe, run in conduit from first fix, terminates into the thermostat at this stage and is tested before the thermostat fascia goes on. The Part P electrician returns to commission the UFH circuit and to sign off the bathroom electrical installation as a whole — a single certificate for the lighting, the heating cable, the towel rail, the extract fan and the thermostat. The certificate is filed and included in the handover pack.
The final stage is decoration and fittings. The walls above the tile take a dusty pink in a mid-sheen finish chosen to hold the room together with the coral tones of the feature wall without competing with them. A drum-style flush ceiling pendant centred on the room provides ambient light, with four recessed downlights flanking it on a separate switching circuit so the room can be lit either softly or fully. The oak door is hung on quality hinges and finished in a satin lacquer that complements the dark Shaker vanity. The towel rail is wired, the mirror cabinet is fixed, the toilet roll holder is set at the correct height, and the snag list is closed personally before handover.
The room was unusable for three weeks. It came back as a family bathroom that performs at master-suite specification: warm underfoot from the first step out of the shower, watertight from the substrate up, and confident enough in its design language to hold the eye in a small footprint. Compact does not mean simplified. It means every decision has to earn its place, because there is nowhere for a wasted line or a careless joint to hide.
Small bathrooms are where corners are most often cut, because the visible finish hides almost everything. These are the questions worth asking before the work begins.
Ask for the tanking specification in writing — brand, coverage rate, number of coats, reinforcing tape at corners and penetrations. We specify full-room tanking on every bathroom we build. A small bathroom with a slow leak still destroys the ceiling below.
A combined uncoupling-and-heating membrane keeps the floor build-up thin and protects the door-threshold transition. Ask how the floor levels resolve at the threshold — if it is not measured at strip-out, it will be improvised at fit-out, and it will show.
Bathroom electrical work must be carried out by a Part P certified electrician, and you should receive a single certificate at handover covering UFH, lighting, towel rail, extract fan and thermostat. Ask to see it. If it isn’t offered, the work isn’t to standard.
In a small room with three tile patterns, set-out is the difference between dense and incoherent. Ask how the patterns will set out from the focal points — bath rim, doorway, vanity centre — before any tile goes down.
Every joint that disappears behind tile should be pressure tested and signed off before second fix is closed up. If it has not been documented, it has not been done. Photographs of every concealed layer should be in the handover pack.
A small bathroom is not a reduced specification — it is the same specification in a smaller space. The same tanking, the same pressure tests, the same Part P certified electrical work, the same documentation. Anything less is a shortcut against a future leak.
Family bathrooms, en-suites and master suites are built to the same seven-stage sequence whatever the postcode. The local conditions — mansion-block acoustic specifications, listed-building consent, conservation-area constraints — shape what is possible at the design stage. We work to those constraints across Prime London and the wider South East.
Igor will arrange a free consultation at your London property within 48 hours. The brief is written from the room as it actually is, not from assumptions — survey first, design second, build third. Photography of every concealed layer is included on every project at no extra cost.