What I Wish I Knew Before My Bathroom Renovation

In short: The things people most often wish they had known before a bathroom renovation are that the room should be measured before the suite is bought, that the real cost is in what sits behind the tiles, that moving the toilet is the most expensive change, and that storage, lighting, sockets and ventilation have to be decided before the walls are closed up. A contingency of around 15% and a realistic programme of 7 to 12 working days avoid most of the rest.

01 What do I wish I knew before my bathroom remodel?

Most bathroom regrets come from decisions made in the wrong order: products chosen before the room was measured, a budget set before anyone looked behind the old tiles, and storage, lighting and sockets left until the walls were already tiled. Almost every one of the lessons below is a decision that costs nothing if it is made at the survey and a great deal if it is made halfway through.

These are the twelve we hear most often, from people who have renovated a bathroom before and from what we find when we open up rooms that someone else fitted.

02 1. Measure the room before you buy the suite

Don't buy the suite until the room has been measured. Consider the options for the layout first, make sure the door swing and the shower still work, then buy the suite. A bath that is 50mm too long, a shower tray whose waste sits over a joist, or a toilet whose outlet does not line up with the soil pipe is an expensive change once it has been delivered. If you are buying your own suite, get the drawing agreed and the measurements checked first.

03 2. The real cost is behind the tiles

What the bathroom is built on decides more of the price than the taps do. Blown plaster behind the old tiles, a soft floor under the bath, or old pipework with no isolation valves all have to be put right before the new room goes in. A survey that looks at the walls and floor, with a board lifted if necessary, is what turns a guess into a fixed price. Our guide to the signs your bathroom needs replacing explains what to look for.

04 3. Moving the toilet is the most expensive change

Moving the toilet, or anything else that changes where the waste runs, is usually the single biggest cost in a bathroom. Its waste has to reach the soil stack with a proper fall, so the distance and the route decide what is possible. Keeping the toilet roughly where it is and moving the basin and shower around it is often the best value layout.

05 4. Waterproofing matters more than the tiles

Grout and tiles are not waterproof. Behind a shower, the wall needs a tanking system or a waterproof board, sealed into every joint and corner, before it is tiled. It is invisible on the day the bathroom is finished and it is the main reason a well-fitted bathroom lasts twenty years and a poor one leaks in three. Our guide to tanking explains how it is done.

06 5. Plan the storage before the walls are closed

You will always need more storage than you think, and it is the best way to keep a small space looking clear. A recessed niche in the shower wall, a vanity unit with drawers rather than a pedestal basin, and a mirrored cabinet all have to be planned before tiling, because a niche has to be built into the wall and a cabinet needs fixings and possibly a power supply. Bottles on the edge of the bath are the most common regret of all.

07 6. Decide the lighting and sockets at first fix

Lighting, a shaver socket, a lit mirror, an electric towel rail and underfloor heating all need wiring that goes in before the walls are boarded. Bathroom electrics are notifiable under Part P in some cases and must suit the bathroom zones, so they are not something to add once the tiles are up. Think about where you stand to shave or do make-up, and light that spot well.

08 7. A heated towel rail and underfloor heating are worth it

Of all the upgrades, a heated towel rail and underfloor heating are the two people most often wish they had added. Electric underfloor heating in a bathroom is relatively cheap to fit at the same time as the floor, and it frees the wall a radiator would have taken. Our underfloor heating guide compares electric and wet systems.

09 8. Ventilation stops the mould

A bathroom without proper extraction will grow mould whatever it cost. Approved Document F sets the extraction rate a bathroom needs, and the fan should be ducted to the outside, not into the loft, with an overrun timer so it keeps running after the light goes off. An opening window is not enough on its own, especially on a cold external wall.

10 9. Choose the grout colour and order extra tiles

Grout colour changes how a tiled wall looks as much as the tile does: white grout on a dark floor shows every mark, while a mid-grey hides them. Order around 10% more tiles than the area needs for cuts and breakages, more for herringbone or diagonal layouts, and keep a few spare from the same batch for future repairs.

11 10. Lead times decide the start date

The start date is often set by deliveries, not the fitter. A made-to-order vanity, a particular tile or a shower screen in a non-standard size can take several weeks to arrive, and a bathroom cannot be started with half the suite missing. Order early and have everything on site before the strip-out.

12 11. Budget for the unexpected

Set aside a contingency of around 15% for what is found when the old bathroom comes out, which is the allowance MyJobQuote recommends in its 2026 cost guide. In older houses that might be rotten boards, a corroded soil stack or wiring that needs replacing. A fixed written quote after a proper survey keeps surprises to a minimum. Our guide to what a bathroom renovation costs has the published 2026 figures.

13 12. Plan for living without the bathroom

A complete bathroom takes 7 to 12 working days when one team works through it without gaps. If it is your only bathroom, ask how the toilet will be kept working, how long the water will be off, and when the room will be usable again. Our preparing for a renovation checklist covers the practical side.

14 What makes a bathroom look tacky?

What makes a bathroom look tacky is usually too many ideas in one small space: several tile designs on the same wall, a busy border, mismatched metal finishes, and accessories crowding every surface. Poor workmanship looks worse than any style choice, though: uneven grout lines, thick silicone in place of a neat joint, a door that catches the toilet, and tiles cut badly around a window. Choose one or two finishes, make sure the tiling is done well, and keep the surfaces clear with good storage, and even a small bathroom will look considered rather than cheap.

15 What are the most common bathroom renovation mistakes?

The most common bathroom renovation mistakes are tiling over plaster that has already failed, leaving out the tanking behind a shower, venting the extractor into the loft, buying the suite before the room is measured, and leaving storage, lighting and sockets too late. Each one looks fine on handover day and causes leaks, loose tiles, mould or regret within a few years.

16 What is the hardest part of a bathroom remodel?

The hardest part of a bathroom remodel is the sequence: getting the plumbing, electrics, plastering, tiling and joinery to follow each other without gaps, each starting on a surface the last trade left ready. When the trades are booked separately, the job runs to whoever is slowest, and a bathroom can sit half-finished for weeks. Our guide to the order to renovate a bathroom sets out the correct sequence.

Barbers Bathrooms & Kitchens runs every one of those trades with its own team, so the sequence is one programme rather than five diaries. See our bathroom installation service for how it works.