Bathroom planning guide
How to plan a bathroom renovation, from start to finish
A plain-English, step-by-step guide for UK homes: budget, style, layout, the rules, and how to measure and order the right vanity unit first time.
The whole project at a glance
Most of a renovation happens before anyone picks up a tool. Allow about three months from first ideas to finished room. The fitting itself usually takes one to three weeks.
Step 1
Set your budget
Start with a number you are comfortable with, then add 10–20% for surprises. Old bathrooms hide rotten floorboards, leaking joints and tired wiring, and you only find them once the old suite is out.
Labour is usually the biggest single cost, at around 45–60% of the bill. Fitters in Yorkshire and the North typically charge £180–£220 a day; in London expect £300–£350.
Where you can save, and where you shouldn’t
- Keep the toilet where it is. Moving it means moving the 110mm soil pipe, which is often the most expensive change in the room.
- Spend on the things you touch every day: the vanity unit, the taps and the shower valve. Cheap ones show their age fast.
- Save on wall tiles by tiling only the wet areas and painting the rest with a good bathroom paint.
- Don’t skimp on hidden work: waterproofing, ventilation and pipework are hard to fix once the tiles are on.
Step 2
Choose your bathroom theme
Pick a style before you pick products. It makes every later choice easier, from tiles to taps. A simple way to build a scheme that feels calm and finished is the 60-30-10 rule:
Six bathroom themes that work well with a painted vanity
Classic heritage
Shaker doors, panelled walls, metro or encaustic tiles, a deep navy or off-white vanity and brushed brass or polished nickel.
Modern country
Sage or olive cabinetry, warm stone or terracotta floors, natural wood, and matt black or aged brass fittings.
Calm spa
Soft greige or warm white, large-format stone-effect tiles, a wall-hung vanity to show more floor, and brushed nickel.
Bold and characterful
A strong colour on the vanity (pink, plum, mustard or deep green), patterned floor tiles and plain walls to let it breathe.
Clean contemporary
Plain drawer fronts, a dark charcoal or crisp white vanity, simple white or concrete-look tiles and slim bar handles.
Coastal and light
Soft blue or pale grey cabinetry, white tongue-and-groove panelling, pale oak and chrome or polished nickel.
See real colours in real bathrooms
Our painted vanity colour ideas page shows white, blue, green, grey, pink and black vanities in customers’ homes. We can also colour-match shades from Farrow & Ball, Little Greene, Dulux, Lick and others. For more inspiration, browse our customer photos and compare our worktop finishes beside your chosen colour. To see which wall and woodwork colours suit each of our vanity colours, try colours that go together.
Tips for choosing colours you’ll still love
- Look at samples in your own bathroom, morning and evening. North-facing rooms make colours look cooler and darker; south-facing rooms warm them up.
- Put all your samples together: tile, worktop, paint and a handle. Colours that look good alone can clash side by side.
- Match the metals. Choose one finish for taps, handles, shower and mirror, or two at most.
- Check the undertone of whites. A warm off-white vanity can look dirty next to a cold, bright white basin.
- Order samples of our paint colours and worktops so you can see them in your own light.
- Pin it all on one board (or a Pinterest board) before you order anything.
Step 3
Plan the layout
Draw your room to scale on squared paper (one square for every 10cm works well). Mark the door, window, radiator and, most importantly, where the soil pipe leaves the room. The toilet usually has to stay close to it.
Then leave enough space to use each fitting. A good rule, from British Standard BS 6465-2, is about 700mm of clear floor in front of the basin and the toilet, and at least 400mm from the middle of the toilet to a wall or cabinet.
Plans are drawn to the same scale. Shaded areas show the 700mm of clear space in front of the basin and toilet.
Layout checklist
- Doors open without hitting the basin, toilet or a drawer pulled open.
- The basin is out of the main splash of the shower.
- Towel rail and radiator are within reach of the bath or shower.
- There’s space to open the vanity’s drawers or doors fully (allow about 500mm in front).
- A light over the mirror, and a mirror height that suits the tallest and shortest person using it.
Step 4
Measure for your vanity unit
Measure in millimetres and write everything down. Walls are rarely straight, so measure the width in three places and use the smallest figure. The width you choose is the cabinet, and the worktop overhangs it by 10mm each side. Fitting wall to wall in a recess? Email us before you order and we’ll make the top to fit.
Your measuring checklist
- Width at three heights. Use the smallest.
- Depth available from the wall to the nearest obstacle: the door swing, toilet or bath edge. Our standard units are 500mm deep (510mm with the worktop).
- Pipe positions: hot, cold and waste, measured from the floor and from one side wall.
- Skirting and tiles: note their thickness. New tiles or boards can take 15–25mm off each wall.
- Mark it out: stick masking tape on the floor where the unit will go and live with it for a day or two. Open the door, use the toilet, walk past it.
- The delivery route: measure front door, hallway, stairs and bathroom door, especially for doubles up to 2000mm wide. Our delivery is to a ground-floor room, so plan help to carry it upstairs.
Allow for new walls. You’ll usually order before the old tiles come off, so take off the thickness of any new boards and tiles, and ask your fitter to check your figures. If you’re unsure, send us your measurements and we’ll go through them with you.
For more detail, see our guide to measuring for a vanity unit.
Step 5
Choose and order your vanity unit
A vanity unit is a basin, storage and worktop in one. Getting a few decisions right at this stage saves problems on fitting day.
Countertop or undermount basin?
A countertop basin sits on top of the worktop like a bowl. It’s a strong design feature and easy to swap later. An undermount basin sits below the worktop, so you can wipe water straight into it. Our units are made at different heights for each, so the basin ends up at a comfortable height either way.
Standard depth or cloakroom depth?
Our units are 500mm deep as standard. For cloakrooms and narrow rooms, our single countertop units (wall-hung ones included) can be made 400mm deep. On these, the tap sits on a back corner, to the left or right of the basin and angled at 45° towards it, instead of behind it. Double countertop units can be made 400mm deep on request: just ask us.
One basin or two?
Two basins are handy for couples in a busy morning. One basin gives you more worktop for a wash bag or a plant. On our double units you can choose two basins, or one basin centred, to the left or to the right. Each basin is priced as you choose it.
Check where the pipes come in
Pipes can come up through the floor or out of the wall, whether the unit has drawers or doors, as long as they are kept close to the wall. Most of our units that go down to the floor have a void at the back for the pipes. Units with open shelves need the pipes to come out of the wall. Plan this before the walls are boarded. Plumber’s packs are available for our units, so your plumber can put the pipes in the right place before your unit arrives. Just ask us.
Wall-hung units need solid fixings
A wall-hung vanity, such as the Bedale or Bentham, shows more floor and makes a small room feel bigger. It must be fixed into masonry, or into timber noggins fitted between the studs before the wall is boarded. Plasterboard alone won’t hold it.
Your vanity ordering checklist
- Width that fits your smallest measurement, allowing for the worktop’s 10mm overhang each side. Wall to wall in a recess? Email us before you order.
- Depth: 500mm standard, or 400mm for a cloakroom vanity unit.
- Single or double, and for doubles, one basin or two and where it sits.
- Countertop or undermount basin.
- Tap position: behind the basin, on a back corner (400mm units), or wall-mounted. Wall-mounted taps need their pipes in the wall before tiling.
- Colour, handles and worktop finish.
- Using your own basin or taps? Send us the exact model so we can cut the worktop to suit.
- Timing: our units are made to order and usually delivered in 4–5 weeks. Order about 8 weeks before your fitter needs it.
Compare by type: single countertop, single undermount, double countertop and double undermount.
Step 6
Find your trades and check the rules
A full renovation usually needs a plumber, an electrician, a tiler and sometimes a plasterer or joiner. Many bathroom fitters manage all of them for you.
Finding good tradespeople
- Get three written quotes from the same written brief, so you can compare like with like.
- Ask to see photos of recent bathrooms, and speak to one or two past customers.
- Check electricians on the Competent Person Register, and anyone touching gas on the Gas Safe Register. TrustMark lists vetted firms for all trades.
- Agree payments in stages as work is done. Avoid paying more than a small deposit up front.
- Get the start date, the length of the job and what’s included in writing.
Building regulations in plain English
Replacing a bathroom like for like doesn’t usually need planning permission. But some parts of the job are covered by building regulations:
| Work | What the rules say |
|---|---|
| Electrics (Part P) | New circuits, a new consumer unit, and most electrical work in a room with a bath or shower must be done by a registered electrician who certifies it, or be notified to building control first. |
| Ventilation (Part F) | A bathroom needs an extractor fan of at least 15 litres a second, ducted to the outside. With no opening window, it should run on for 15 minutes after you leave. |
| Drainage (Part H) | New connections to the soil pipe or drains, such as moving the toilet, should be notified to building control. |
| Structure (Part A) | Removing walls, or cutting into floor joists for pipes, has strict limits. Ask a builder before anything is cut. |
| Listed buildings and flats | Listed homes may need listed building consent. In a flat, check your lease and ask the freeholder first. |
This is general guidance for England. Rules in Wales, Scotland and Northern Ireland are similar but not identical. For the full detail, see the Planning Portal bathroom guide and the government’s Approved Document F, or ask your local building control.
Electrical zones in a bathroom
The wiring regulations split a bathroom into zones around the bath and shower. The closer to water, the stricter the rules on what can go there and how well it must be sealed (its IP rating). Every circuit in the bathroom must be protected by a 30mA RCD.
Step 7
Order everything else
Have everything delivered and checked before the old bathroom comes out. A missing waste or a broken tile can stop work for days while your bathroom is out of action.
| Item | Typical lead time | Tip |
|---|---|---|
| Made-to-order vanity unit | 4–5 weeks | Order first. Agree the exact size and pipe positions with your fitter. |
| Tiles | 1–3 weeks | Order 10% extra, or 15% for patterned tiles or tricky layouts. Keep a few spares. |
| Bath, shower tray, toilet | 1–2 weeks | Check sizes against your plan and that the toilet suits your soil pipe position. |
| Taps, shower valve, wastes | 1–2 weeks | Check they suit your water pressure. Wall-mounted taps and concealed valves are fitted at first fix. |
| Extractor fan, lights, mirror | 1 week | Check the IP rating suits the zone it goes in. |
Step 8
Strip out and first fix
Work on site starts with the noisy, dusty part. The old suite and tiles come out, then the plumber and electrician run new pipes and cables inside the walls and floor. This is called first fix, and it’s your last easy chance to change the layout.
- Turn off the water and arrange somewhere else to wash for a week or two.
- Check the floor. Replace any soft or rotten boards and screw the floor down to stop it moving.
- Agree the exact pipe positions for the vanity, using its size and your basin and tap choice.
- Fit noggins for a wall-hung vanity, radiator, towel rail, mirror and grab rails now.
- Take photos of every pipe and cable before the walls are closed up. They’re very useful later.
Getting the waste to drain well
Waste pipes need a steady, gentle fall to the soil pipe or drain, so water runs away without gurgling or blocking.
Step 9
Boards, waterproofing and tiling
Water gets through grout. Behind the tiles, the wall has to cope with that, especially around the shower and bath. In wet areas, use cement-based tile backer board, or a waterproof board, and tank (waterproof) it before tiling. Moisture-resistant plasterboard is fine for walls away from the water.
- Floor first or walls first? Ask your tiler. Many tile the floor first, then fit the vanity and toilet, then tile the walls around them.
- Tile behind the vanity? For a freestanding unit, tile at least the area just above the worktop. Our worktops come with a matching upstand to protect the wall: 150mm tall on the White worktop and 100mm on the patterned ones.
- Let it dry. Leave adhesive and grout to cure for at least 24 hours before silicone or heavy use. New plaster can need a week or more before painting.
- Keep your vanity out of the dust. Store it wrapped in a dry room until tiling and plastering are finished.
Step 10
Second fix and finishing
Second fix is when the room comes together: the vanity, basin, taps, toilet, shower, lights, fan and accessories go in, and everything is connected and tested.
- Level the vanity unit carefully and fix it to the wall. Check doors and drawers run smoothly once it’s level.
- Seal along the back of the worktop and around the basin with a good bathroom silicone.
- Fill the bath with water before you silicone around it, so the seal doesn’t crack when it’s used.
- Run every tap and check under the vanity for drips over the first few days.
- Collect your paperwork: the electrical certificate, building control completion certificate if needed, and product guarantees.
- Look after your painted vanity: wipe up standing water, use the extractor fan, and avoid harsh cleaners. Our care and guarantee page has the details.
Fitting one of our units?
Your vanity unit, worktop and splashback, basin and taps arrive as separate parts, ready for your fitter to put together. Nothing is glued or plumbed in at our workshop, so each part can be carried in safely and fitted to suit your walls and pipework. Taps from us come with the waste and trap, and the worktop is already cut to fit your basin and taps. Your plumber fits and connects them like any other basin. If anything isn’t clear, call or email us: we made it, so we can help.
Watch and learn
Helpful videos
These independent videos, mostly from UK tradespeople, show the main jobs clearly. They’re useful even if you’re hiring a fitter, so you know what good work looks like.
- How to fit a bathroom vanity unit and basin, step by stepplumberparts on YouTube
- How to install a vanity unit basin: 8 costly mistakes to avoidplumberparts on YouTube
- How to install a floating (wall-hung) vanityMr and Mrs DIY on YouTube
- Tiling a shower? Do this first: shower waterproofingTheBespokeBloke on YouTube
- Bathroom zones explained: zones 0, 1 and 2 and IP ratingsGSH Electrical on YouTube
Bathroom renovation questions
How long does a bathroom renovation take?
Fitting usually takes 3–5 working days for a cloakroom, 1–2 weeks for a family bathroom, and 2–3 weeks or more if you move things around. Allow 8–12 weeks before that for planning and ordering.
Do I need building regulations approval for a new bathroom?
Not usually for a like-for-like replacement. You do need to follow the rules for electrics (Part P), ventilation (Part F) and any new drainage connections (Part H). A registered electrician can certify their own work. If you move the toilet or change the structure, speak to building control first.
What size vanity unit do I need?
Measure the wall in three places and use the smallest width, allowing for the worktop’s 10mm overhang each side. Fitting wall to wall in a recess? Email us before you order and we’ll make the top to fit. Then check you’ll still have about 700mm of clear floor in front of it. As a guide, 500–600mm suits a cloakroom or small en suite, 800–1000mm a family bathroom, and 1200mm or more works well for two basins.
Countertop or undermount basin: which is better?
Neither is better; they suit different rooms. A countertop basin is a feature and is easy to replace. An undermount basin is easier to keep clean because you can wipe straight into it. We make our units at different heights for each, so the basin height is comfortable either way.
When should I order my vanity unit?
About eight weeks before your fitter needs it. Our units are made to order in Yorkshire and usually delivered in 4–5 weeks, and it’s best to have everything on site before work starts.
Will a painted vanity unit cope with a steamy bathroom?
Yes, with good ventilation. Our units are spray-finished in specialist Renner furniture paint. Run the extractor fan when you bathe or shower, and wipe up standing water rather than leaving it on the paint.
Can I fit a vanity unit myself?
If you’re handy, fixing the unit is straightforward. Connecting the water and waste needs care, and new electrical work in a bathroom must be done by a registered electrician. If in doubt, use a plumber for the connections.
Ready to choose your vanity?
Every Belwood & Roe vanity unit is handmade and painted to order in our Ossett workshop. Choose the size, colour, worktop, basin and taps online, or talk it through with us first.
