How to Plan a Bathroom Renovation: Step-by-Step

A bathroom renovation is one of the most rewarding home improvements you can make. A well-planned project can transform a tired, cramped room into a space you genuinely enjoy using every day. But get the planning wrong and you risk overspending, delays, or ending up with a bathroom that does not quite work for you.

Having fitted bathrooms across Surrey, Sussex and Kent for years, I have seen the difference that thorough upfront planning makes. This guide walks you through every stage of the process, from setting your budget to the moment the last tile goes in.

Step 1: Set a Realistic Budget

Your budget is the single most important decision you will make, and everything else should flow from it. Before you look at a single tile or tap, sit down and decide what you can comfortably spend, including a contingency of around 10–15% for unexpected costs. In older properties especially, surprises like rotten floorboards or hidden pipe work are not uncommon.

As a rough guide, a budget bathroom renovation in Surrey and Sussex typically starts from around £3,000–£5,000. A mid-range project with quality fittings and full tiling runs £5,000–£10,000, and a premium renovation with bespoke features can exceed £15,000. For a full breakdown, see our bathroom renovation cost guide.

Knowing your budget before you speak to a fitter means they can give you realistic options rather than a wishlist that does not match your finances.

Step 2: Measure the Space Accurately

Take careful measurements of your bathroom before you do anything else. You will need the length, width and ceiling height, plus the positions of the door, window, soil pipe, existing waste outlets, and any radiator or towel rail locations. Note which walls are load-bearing if you are thinking about any structural changes.

Accurate measurements allow you to plan the layout properly, understand how many tiles you will need, and avoid ordering fittings that simply will not fit. A wall-hung vanity unit that looks perfect online may be too deep for a narrow bathroom. A freestanding bath might leave no space to open the door. Measure twice, order once.

Step 3: Plan the Layout — Keep or Move the Plumbing?

This is one of the biggest decisions in any bathroom renovation, and it has a significant impact on cost. Keeping the plumbing in its current positions is the most cost-effective approach. If your toilet, basin, and shower or bath can stay where they are, you avoid the labour and materials involved in rerouting waste pipes, extending water supply lines, and potentially lifting floor boards or breaking into walls.

That said, there are times when moving things makes sense. If the current layout is genuinely awkward — a toilet positioned directly opposite the door, a basin that blocks natural movement — the investment in re-plumbing may be worth it for the improvement in usability.

Speak to your fitter about this early. A good installer will give you an honest assessment of what is possible within your budget and flag any structural or drainage constraints before you commit to a layout.

Step 4: Choose Your Fittings and Fixtures

Once the layout is agreed, you can start choosing the fittings. Work through the major items first: toilet, basin, bath or shower enclosure, and storage. Shower valves, taps, towel rails, and mirrors can follow once the big decisions are made.

Think about your household's needs rather than just aesthetics. If you have young children, a bath is still useful even if you primarily use a shower. If mobility is a concern now or in the future, a wet room or level-access shower is worth considering. Wall-hung sanitaryware looks sleek and makes cleaning the floor easier, but requires a solid wall to fix to.

You do not need to use your fitter's preferred suppliers. Many clients buy their own suite and fixtures, which can save money, but always share the product specifications with your fitter before ordering to confirm everything is compatible.

Step 5: Choose Tiles and Wall Finishes

Tiles are where the character of a bathroom really comes to life, but they are also where budgets can quickly grow. Floor tiles need a slip-resistance rating of at least R9 for domestic bathrooms — your retailer should be able to confirm this. Large-format tiles (600×600mm or bigger) can make a small bathroom feel more spacious, but they require a very flat, level floor to lay properly.

If you are tiling floor to ceiling, factor in the additional time and materials cost compared to a half-tiled room. Waterproof wall panels are a practical alternative — they are quicker to fit, easier to keep clean, and come in a wide range of finishes that can be difficult to distinguish from real tile at a glance.

Step 6: Find a Trusted Fitter

Choosing the right person for the job matters more than almost any other decision. Look for a bathroom fitter with verifiable reviews, examples of recent work, and clear, written quotes. Ask whether they handle all trades themselves or subcontract electricians and plasterers, and confirm that any electrical work will be carried out by a Part P qualified electrician.

Get at least two or three quotes, but do not automatically go with the cheapest. A quote that seems suspiciously low may cut corners on waterproofing, use inferior materials, or rely on you not noticing until problems appear months later. Ask each fitter to walk you through their quote line by line so you understand exactly what is included.

Step 7: Agree a Realistic Timeline

A standard bathroom renovation takes around five to eight working days for a straightforward strip-and-refit. More complex projects involving wet rooms, underfloor heating, or significant plumbing changes can take ten to fourteen days. Factor in time for materials to arrive — some tiles and fittings have lead times of two to four weeks — and build in some flexibility around the fitter's availability.

Think about timing in your household. You will be without a functioning bathroom for at least part of the project. If you have only one bathroom, agree with your fitter how they will manage access to the toilet during the work.

What to Expect During the Work

The first day or two of any renovation is the noisiest and messiest: stripping out the old fittings, removing tiles, and preparing the room. After that, the project becomes more constructive — boarding, tanking if needed, first-fix plumbing, tiling, and then fitting sanitaryware and finishing touches.

Expect dust to spread beyond the bathroom itself, even with dust sheets in place. A good fitter will protect carpets and floors along the route they are working, but some disruption is inevitable. Most clients find the best approach is to clear the area and let the work proceed without hovering — you will be back in the room soon enough.

Daily communication from your fitter about progress, any unexpected findings, and the plan for the following day keeps things running smoothly and avoids surprises on either side.