Renovating a bathroom looks straightforward on paper: a few square metres, a shower, a washbasin and a toilet. In practice it is one of the trickiest jobs in the home, because six different tradespeople have to dovetail exactly in a cramped space, and because mistakes only become visible years later, when a damp patch appears on the neighbours' ceiling. This article is about the execution: the order of the steps, who does what, what makes or breaks the waterproofing and what you arrange in advance with the municipality, the VvE (owners' association) and the neighbours. This article deliberately says nothing about costs; for that, read What does a bathroom renovation cost in 2026.
Step 0: the planning determines everything that follows
Most problems in a bathroom renovation arise before anyone has started work. Start with the layout: will the toilet, shower and washbasin stay where they are, or will they move? Keeping the pipework is quicker and saves time and demolition work; moving the pipework gives you freedom, but requires more cutting and breaking and a new route for the drain. That drain is precisely the limiting factor: a waste pipe needs a fall to flow, at least half a centimetre per metre (1:200 according to NEN 3215), in practice often a centimetre per metre, and must connect to the soil stack or the existing drainage. If you want to move a shower or toilet a few metres on a floor with a concrete slab, you quickly end up with a raised floor or a lowered ceiling at the downstairs neighbours'; on a timber floor there is often more space between the joists.
Also include the following points in the planning:
- Ventilation. The Besluit bouwwerken leefomgeving (Bbl, the Dutch Building Decree) requires an air extraction rate of at least 14 dm³/s for a bathroom, mechanically or via an exhaust duct; for a toilet room the figure is 7 dm³/s (Article 4.122 Bbl). A fan that only switches on with the light and stops immediately does not achieve this; an overrun timer or humidity sensor is a must in practice, especially in a bathroom without a window.
- Electrics and zones. The standard NEN 1010 divides the space around the bath and shower into zones. Zone 0 is the inside of the bath or shower tray, zone 1 the area directly above it up to a fixed height, zone 2 the strip around that. Zone 1 runs up to a height of 2.25 metres, zone 2 is a 60-centimetre strip around it. Each zone has a minimum degree of protection against water (IPX7 in zone 0, IPX4 or higher in zones 1 and 2); switches and ordinary wall sockets are not permitted in the zones, the only exception being a shaver socket with an isolating transformer in zone 2. Outside the zones, ordinary wall sockets are allowed, and all circuits feeding the bathroom must be protected by a 30 mA residual current device. Electric underfloor heating, a washing machine or a water heater usually gets its own circuit. You can read more about the standard in May I install electrics myself.
- Underfloor heating. Water-based underfloor heating requires a thicker screed and a connection to the central heating or heat pump; electric underfloor heating is thin and quickly arranged, but intended as comfort heating, not as the main heating. Decide this before the plumber and the electrician come, because it determines the floor build-up and the height of the drain.
- Walk-in shower or shower tray. A shower tray is the safest choice for waterproofing: the water stands in a tray connected to a drain. A walk-in shower tiled to a fall looks better and has no threshold, but requires a linear drain or floor drain with a sealing flange, a screed sloping towards that drain and waterproofing that forgives no mistakes. On a timber upper floor, this is extra critical.
- Dimensions of the sanitary ware. Wall-hung toilet, shower mixer, washbasin and mirror lighting have fixed heights and connection points. Choose the sanitary ware before the plumber and the electrician start work; moving a pipe afterwards means tiles coming out.
Step 1: demolition and the asbestos check
The demolition is done by a contractor, a handyman firm or a specialist demolition company: tiles, sanitary ware, screed, ceiling and any stud walls come out, down to the bare structure. Have the condition of the floor and walls underneath checked in advance: a damp or rotten timber floor, a sunken screed or a pipe in an unexpected place comes to light at this point and must be resolved first. If your home was built before 1994, an asbestos check is something you must think about, and for demolition it is also the legal starting point: the Bbl requires an asbestos inventory report as soon as asbestos can reasonably be expected and only exempts buildings from after 1 January 1994 (Article 7.9); demolition that releases asbestos must be reported four weeks in advance (Article 7.10). Asbestos is not only found in corrugated sheets, but also in old tile adhesive, window sills, vinyl flooring and the insulation around central heating pipes. A company carrying out demolition may not simply remove material suspected of containing asbestos; that requires a certified inventory and usually a certified removal contractor. What you can recognise yourself and how the rules work is explained in Recognising asbestos when renovating.
Steps 2 and 3: the plumber and electrician lay the invisible work
After the demolition comes the first-fix pipework. The plumber lays the cold and hot water pipes, the drains from the shower, washbasin, toilet and possibly washing machine, the connection to the soil stack and the pipes for the radiator or underfloor heating. They install the concealed cistern of a wall-hung toilet and the concealed parts of the taps at the right height. Ask for a pressure test of the water pipes before the walls are closed: a leak in a pipe that has just been plastered in and tiled over is the most expensive leak you can have. In older homes, this is also the moment to replace lead or outdated pipes and to assess whether the existing drain can cope.
In parallel or immediately afterwards, the electrician lays the cables for lighting, the fan, the mirror lighting, any wall sockets outside the zones, the electric underfloor heating and the supplementary equipotential bonding (the earth connection of metal pipes and parts, if the standard requires it). They install the circuits in the consumer unit and provides the residual current protection. At this point all the pipes and cables are exposed: go through the drawing with both tradespeople, check heights and positions and take photos of where the pipes and cables run. Those photos are worth their weight in gold if someone needs to drill later.
Step 4: walls, screed and drying
The plasterer or contractor closes the chases, puts up stud walls or cement-bonded boards and makes the walls flat and square as a substrate for tiling; the same applies to smooth plasterwork outside the wet zone. In the shower corner, ordinary plasterboard is not a good substrate; even the green moisture-resistant version is moisture-resistant and not waterproof; cement-bonded or foam-core building boards are the norm there. The screed is laid to a fall towards the shower drain if there will be a walk-in shower, and with the underfloor heating pipes embedded in it. Then comes the step that is too tight in every schedule: drying. As a rule of thumb, a cement-bonded screed needs a week per centimetre of thickness before it may be tiled, with a minimum of around four weeks, and more for thicker floors; an anhydrite floor must be sanded and primed. Tiling too early on a wet screed results in tiles coming loose and damp problems coming from below. Have the tiler measure the residual moisture (CM measurement) instead of relying on the calendar.
Step 5: waterproofing, the step where most leaks begin
This is where the misconception that causes most bathroom leaks lies: tiles and grout are not waterproof. Cement grout absorbs water, sealant joints crack or come loose after years, and the water behind the tiles then ends up in the wall or floor. The watertightness of a bathroom therefore does not lie in the tiles, but in the layer next to them: the waterproofing under the tiling. In a properly executed bathroom, this consists of:
- Liquid waterproofing membrane or waterproofing sheet on the floor and walls in the wet zone: the entire shower corner to well above the shower head, the floor around it and, with a timber floor, preferably the entire bathroom floor, applied in two coats and with an upstand along all walls.
- Sealing tape in all corners where floor and wall meet and in vertical corners: a flexible tape that is worked into the waterproofing, so that movement of the structure does not crack the layer.
- Sealing collars around every pipe penetration: tap connections, the penetration of the shower drain and the washbasin waste. A penetration without a collar is a hole in your waterproofing.
- Sealing flange or tape around the shower drain: the linear drain or floor drain has a flange that is incorporated into the waterproofing layer. This is the most critical connection in the entire bathroom.
- Connection of the bath or shower tray to the wall: first a sealing tape under the edge of the tiles, and only then the sealant joint. The sealant is the visible finish, not the waterproofing.
Who does this work differs per project: often the tiler, sometimes the contractor or a specialist company. More important than who is that it is stated explicitly in the quote and that you see it before the tiles go on. Ask for a photo of the finished waterproofing, including sealing tape and collars, as part of the file. A leak from this layer does not show itself in the bathroom itself, but as a damp patch on the ceiling below, loose tiles or mould in the adjoining room, and often only after months or years. How to recognise these kinds of problems and whom to call then is explained in Recognising damp and mould at home.
Step 6: tiling, grouting and sealing
The tiler lays the wall tiles first or the floor first, depending on the working method and the tile format, and starts by determining the tile layout: where the cut tiles fall, how the joints run on from wall to floor and how they line up with the shower drain and the toilet. Large formats and narrow joints require a flatter substrate; mosaic in a shower floor laid to a fall is actually handy, because it follows the slope. The shower floor is given a fall of about 1 to 2 per cent towards the drain, so that water runs away without the floor feeling noticeably sloped. Then comes the grouting, where epoxy grout in the shower corner is more resistant to moisture and dirt than cement grout, and the sealing in all corners, along the bath and shower tray and around sanitary ware: with mould-resistant sanitary sealant on a clean, dry surface and with a backing rod in wider joints, so that the sealant can move. Corners are never grouted, always sealed; a grouted corner cracks at the first movement.
Steps 7 and 8: fitting the sanitary ware, handover and guarantee
Only when the tiling is finished and has cured does the plumber come back for the installation of the sanitary ware: taps, shower head, wall-hung toilet with seat, washbasin with trap, radiator or towel rail. The electrician fits the fan, lighting, switches and mirror and tests the residual current protection and the bonding. Then go through the handover together with the contractor or the individual tradespeople: run every tap and drain, check that the shower floor drains without puddles, inspect all sealant joints and grout and test whether the fan is extracting (a sheet of paper stays against the grille). Record defects in a handover report and agree a period within which they will be repaired; you can find the complete checklist in Handover of your renovation.
Ask for a guarantee on the work, in particular on the watertightness, and record who is liable if a leak develops: with separate tradespeople this differs per part and the parties easily point at each other; with a contractor who takes on the entire job there is a single point of contact. How long a guarantee usually lasts and what it covers is explained in Guarantees after a renovation. Keep the drawing of the pipe routes, the photos of the waterproofing and the product sheets for the tiles, waterproofing and sanitary ware with the guarantee documents.
A contractor or separate tradespeople?
A bathroom requires a demolition worker, a plumber, an electrician, a plasterer or partition builder, a tiler and a sealant specialist, and with a walk-in shower someone who takes responsibility for the waterproofing. You can hire and manage these parties yourself, which can work out cheaper and gives you more choice, but then you are also the one who keeps an eye on the order, plans the drying times, deals with people dropping out and, in the event of a leak, works out who is responsible. A contractor or bathroom specialist takes that over and delivers a complete bathroom under one quote and one guarantee. Many plumbers and tilers work in regular partnerships and together offer a complete bathroom, which is an in-between option. Which choice suits which project is explained in Contractor, construction company or handyman firm. In all cases: the order above is non-negotiable, and whoever keeps an eye on it is the one who carries the project.
In terms of lead time, for a standard bathroom you should count on one to two weeks of demolition and first-fix work, then the drying time of the screed, and then a week to a week and a half for waterproofing, tiling, grouting, sealing and sanitary ware. In total, including waiting times, you will quickly be looking at three to five weeks without a bathroom, preceded by weeks of preparation in which tiles, sanitary ware and tradespeople are booked. Agree where you will shower in the meantime; a temporary shower in the garage or at the neighbours' is not unusual. You can read the comparison with other jobs in How long does a renovation take.
Permit, VvE and neighbours
For a bathroom within the existing walls you generally do not need an omgevingsvergunning (environmental permit): an internal alteration with no consequences for the load-bearing structure, the facade and its insulation, or the fire compartmentation is exempt from permits both technically and in planning terms (Article 2.27 Bbl and Article 22.27 of the bruidsschat, the transitional rules municipalities inherited from national law). That changes if you remove or break through a load-bearing wall to enlarge the bathroom, create a new window in the facade or live in a listed building: then a permit requirement applies, or at the very least a check. For this, read Removing a load-bearing wall and, if in doubt, do the permit check in the Omgevingsloket (the national environment and planning portal). The Bbl also applies without a permit: ventilation, electrical safety and the requirements for drainage and watertightness of a bathroom still apply.
If you live in a flat, the soil stack, the shared drainage and water pipes and often the floor structure are jointly owned. Connecting to or moving those pipes requires permission from the VvE, and the splitsingsreglement (deed of division regulations) or house rules often set requirements for sound insulation under a hard floor and for working hours. Notify the board of the renovation and ask about the rules before the quotes come in; more in Renovating in a VvE flat. Also inform the neighbours: cutting and breaking work in a bathroom is loud and travels through the structure, and a leak ends up with the downstairs neighbours. So check your buildings and contents insurance in advance and ask the contractor about their liability or CAR (Construction All Risks) insurance, so that it is clear who pays if water damage occurs during or after the work. You can read about insurance when renovating in Renovating and insurance.
Checklist for the quote
- Drawing with floor plan, elevations and the positions and heights of all connection points for water, drainage and electrics.
- Material specification: tiles, grout, sealant, waterproofing system, building boards, sanitary ware and taps, with brand and type, and who supplies what.
- Waterproofing explicitly named: which system, on which surfaces and up to what height, with sealing tape, collars and sealing flange, and with a photo as a handover moment.
- Ventilation and electrics: type of fan with overrun timer or humidity sensor, the circuit layout, residual current protection and the zones in which lighting and sockets will be placed.
- Fall and drainage: fall of the shower floor and the drain, type of linear drain or floor drain, and with a timber floor the measures against deflection.
- Demolition and removal: are the demolition, the removal of rubble and old sanitary ware, and an asbestos check for an older home included?
- Schedule: start and end date, drying times stated, and what happens if a subcontractor drops out.
- Extra work and guarantee: provisional sums, the arrangement for unforeseen issues behind the tiles, the guarantee period and who is the point of contact in the event of a leak. How to compare quotes is explained in Comparing quotes; what to do about extra work in Extra work during a renovation.
In short: a bathroom renovation succeeds or fails on the order of work and on the layer you will never see again. First plan the layout, the drainage, the ventilation and the electrical zones; demolish with an asbestos check; have the plumber and electrician do the first-fix work and carry out a pressure test; give the screed time to dry; have the waterproofing with sealing tape, collars and flange applied and photographed before a single tile goes on; and hand over with a handover report and a guarantee on paper. On VerbouwPro you post your bathroom as a job free of charge, and tilers, plumbers, electricians and contractors from your area respond.