A bathroom is small, but it is the most exacting room in a house to get right. It packs plumbing, waterproofing, tiling, ventilation, and electrics into a few square metres, and unlike a bedroom or a living room, almost everything in it is governed by a regulation — because it is a wet room with electricity in it. A checklist is not a nicety here. It is the only way to make sure every decision and every regulatory check happens in the order the work depends on.
The reason the order matters so much is that a bathroom is built in layers that seal each other in. The tanking goes under the tiles, the first-fix plumbing goes into the walls and floor, the electrics follow special-location rules a normal room never sees. Miss a step or run it out of order, and the fix is not a touch-up — it is lifting finished tiling to reach what should have been done first.
A bathroom is decided in layers, and each layer seals the one beneath it. The checklist is the order you cannot reach back into.
What follows is the full bathroom renovation checklist for a UK home, in the order each decision and check has to happen, with the tanking hold point and the bathroom-specific Building Regulations that catch homeowners out across the four UK nations.
Why a bathroom needs a checklist more than any other room
Because it combines water and electricity in a confined space, which means more of it is regulated and more of it is hidden than in any other room. The waterproofing is invisible under the tiles. The electrics follow zone rules that dictate what fitting can go where and how it must be protected. The ventilation is required by regulation, not preference. None of that is obvious from looking at a finished bathroom, which is exactly why it has to be planned rather than discovered.
The checklist turns those hidden, regulated layers into a sequence you can hold a fitter to. A homeowner working from one knows the tanking is verified before the tiling, the first fix before the plastering, the electrical zones confirmed before a single fitting is placed. A homeowner without one finds out about each requirement when an inspector or a fitter raises it, often after the moment to address it cheaply has passed. The budgeting side of the same discipline is in the bathroom renovation cost guide.
The bathroom renovation checklist, in order
Every UK bathroom renovation moves through these stages in this order. Each one produces a decision, a document, or a verified layer the next stage depends on.
- Write the brief. Document who uses the bathroom and how, whether it is a bath, a shower, or both, and the storage and accessibility needs, before any showroom visit.
- Set and validate the budget. Build the number from the trades up, including VAT and a 10 to 20 percent contingency, because a wet room is the most likely to hide a surprise behind the wall.
- Plan the layout. Fix the positions of the bath, basin, WC, and shower, and the drainage falls that serve them. Moving a soil pipe or drain is the most expensive change, so the layout is settled before anything is ordered.
- Choose and specify everything. Lock the suite, taps, shower and valve, tiles, tanking system, extractor, heated towel rail or underfloor heating, lighting, and flooring before quotes go out, so every fitter prices the same bathroom.
- Check the Building Regulations requirements. Confirm the electrical work and zones under Part P, the extractor under Part F, the hot-water scald protection under Part G, drainage, and Building Control if a wall moves. (Detailed below.)
- Get and compare quotes. Issue the written specification to several fitters and compare quotes line by line, with particular attention to whether the tanking and the shower build are fully included. The cheap quote is usually the one that thinned the waterproofing.
- Review and sign the contract. Agree the scope, the stage payments tied to milestones, the dates, and what counts as practical completion, in writing, before any deposit.
- Order the long-lead items. Order the suite, shower screen, and tiles early; the screen is often measured after tiling, so it is ordered to follow. Late items stall an otherwise ready bathroom.
- Strip out and first fix. Remove the old bathroom, then run the first-fix plumbing and electrics to the new layout, and plaster or board the walls ready for tanking.
- Tank and waterproof. Apply the tanking system to the wet areas and let it cure. This is verified before any tiling begins, because once tiles are on it can never be checked again. (Detailed below.)
- Tile. Lay wall and floor tiles onto the cured, verified tanking, then grout and seal.
- Second fix and connect. Fit the suite, taps, shower, screen, extractor, and lighting, connect and test the electrics with the correct RCD protection, and set the scald-protection valve.
- Snag and sign off. Walk the bathroom against a snagging list, have every defect corrected before the final stage payment, and collect the Part P electrical certificate and any Building Regulations paperwork.
Get your bathroom cost baseline first
The free Renovation Cost Calculator gives you a trade-by-trade estimate in under 5 minutes — before your first trade conversation. The number it produces is what every later decision on the checklist is measured against.
The tanking hold point you verify yourself
One step on the checklist matters more than all the others, and it is the one most easily rushed: the tanking. Tanking is the waterproof layer applied to the walls and floor of the wet areas before tiling, and it is what keeps water out of the structure for the life of the bathroom. Once tiles are laid over it, it can never be inspected again — which makes the moment between tanking and tiling the single most important checkpoint in the project.
Treat it as a hold point, not a task. Before the tiler starts, confirm the tanking is complete, taken to the right height in the shower area, and properly lapped at the joints and around the pipe penetrations. A tanking failure discovered later is not a repair; it is lifting the finished tiling to redo the layer beneath it, often with damage to the rooms below. The fifteen minutes spent verifying the tanking is the cheapest insurance in the whole bathroom, and the way it sits within the trade sequence is in the 12 phases of a renovation. The full wet-room sequence around it — strip out, first fix, boarding, tanking, tiling, second fix — is in the order of trades in a bathroom renovation.
Nothing gets tiled until the tanking under it is confirmed. By you, before the tiler starts.
The tanking is the one layer in a bathroom that is both invisible in the finished room and impossible to check once the tiles are on. Every expensive bathroom failure traces back to a layer that was covered before it was verified — and the tanking is the layer that matters most.
The Building Regulations checks specific to bathrooms
A bathroom carries regulatory requirements a dry room never does, because it combines water and electricity. Electrical work in a bathroom is notifiable under Part P and follows special-location zone rules: fittings near the bath or shower must carry the correct ingress-protection rating and the circuits the correct RCD protection. The extractor is required under Part F to clear moisture, and Part G sets the hot-water scald protection — the bath supply limited to 48°C — that a new bathroom must meet. Bodies such as the NICEIC register the competent electricians who can certify the notifiable work.
And the framework changes by nation. England and Wales work to the Approved Documents and notify through LABC or a competent-person scheme; Scotland works to the Scottish Building Standards and may need a building warrant; Northern Ireland has its own Building Regulations and notification routes. The physics of a wet room is the same everywhere, but the route to sign-off and the paperwork you collect differ — confirming the right one for your nation before work starts is what keeps the bathroom compliant, sellable, and insurable.
Where the checklist comes from
The checklist above is the bathroom expression of The 12-Phase System — Property Blueprint Co.'s framework for running a renovation from the first quote conversation to practical completion without paying the variation premium the unprepared homeowner pays. Each item locks a decision or verifies a layer before the trade who depends on it arrives, so the bathroom is built once, watertight, and to a budget that holds.
What sits inside each item — the specification questions, the tanking verification, the electrical-zone rules, the scald-protection setting, the snagging checks — is what separates a homeowner who has a checklist from one who can actually run it. A bathroom is the most regulated and most hidden room in the house, and the checklist is what turns that into a sequence you control rather than a series of surprises. Industry guidance from the Federation of Master Builders makes the same point: the bathrooms that last and finish on budget are the ones fully specified and verified at each layer before the next went on.
See The Bathroom Renovation Blueprint
Every decision in order, with the tanking hold point to verify, the electrical zones to confirm, and the Building Regulations route for your nation — plus a Country Watch covering England, Wales, Scotland, and Northern Ireland.
If the cost baseline is the right first step, use the free Renovation Cost Calculator — a trade-by-trade estimate for the specific bathroom, in under 5 minutes, before any fitter has quoted.
Frequently asked questions
What is the correct order for a bathroom renovation?
Write the brief, set and validate the budget, plan the layout and drainage, choose and specify everything, check the Building Regulations requirements, get and compare quotes, sign the contract, order the long-lead items, strip out and first fix, tank and waterproof, tile, second fix and connect, then snag and sign off. The tanking is verified before the tiling, because once tiles are laid the waterproofing can never be inspected again.
What is tanking in a bathroom?
Tanking is the waterproof layer applied to the walls and floor of the wet areas before tiling, sealing the structure against water for the life of the bathroom. It is invisible in the finished room and impossible to check once tiles are on, which makes the moment between tanking and tiling the single most important checkpoint. Confirm it is complete, taken to the right height, and lapped at the joints before the tiler starts.
Do I need Building Regulations approval for a bathroom in the UK?
Usually for parts of it. Electrical work is notifiable under Part P and follows special-location zone rules; the extractor is required under Part F; Part G sets the hot-water scald protection; and moving a wall or drainage brings in Building Control. Scotland works to the Scottish Building Standards and may need a building warrant, and Northern Ireland has its own regulations, so confirm the route for your nation before work starts.
What are the electrical zones in a bathroom?
A bathroom is a special location under the wiring regulations, divided into zones around the bath and shower that dictate what electrical fittings can be installed where and to what ingress-protection rating, with the circuits carrying the correct RCD protection. This is why bathroom electrics must be designed and certified by a competent electrician, and why the zones are confirmed before any fitting is placed.
What temperature should bathroom hot water be limited to?
Under Part G of the Building Regulations, the hot water supplied to a bath in a new or renovated bathroom must be limited to a maximum of 48°C to prevent scalding, typically by a thermostatic mixing valve. It is a requirement, not an option, and the valve is set and confirmed as part of the second-fix and sign-off stage.
How long does a bathroom renovation take in the UK?
The on-site work is typically two to three weeks for a standard bathroom, including the tanking cure before tiling, but the full timeline door to door is longer once design, specification, quoting, and the lead times on the suite, screen, and tiles are counted — often eight to twelve weeks. Running the checklist keeps the planning weeks from stretching into the build.