Bathroom renovation step by step: from design to finishing
Short answer: A bathroom renovation follows a fixed order: design and planning, demolition, plumbing and electrics, waterproofing, tiling, then fixtures and finishing. Each step waits for the previous layer to dry. Reversing the order risks moisture damage and work that has to be redone.
Prices in this article are indicative Belgian market ranges, not Alpha Services Benelux's price list. Your fixed price is in the quote.
Overview: the six steps in order
A bathroom is a small room where water, electricity and ventilation meet. The order of the work therefore matters more than speed. The table below shows what happens when and what to have checked before the next step starts.
| Step | Work | Checkpoint before the next step |
|---|---|---|
| 1. Design | Layout, fixtures, light points, materials | Plan and fixture list are final; technical limits are known |
| 2. Demolition | Remove tiles, fixtures and old pipes | Substrate is stable, dry and free of hidden defects |
| 3. Plumbing and electrics | Water supply, drainage and wiring | Pipes pressure-tested, drains have enough fall |
| 4. Waterproofing | Membrane on floor and wet zones | Membrane fully cured per the manufacturer's drying time |
| 5. Tiling | Wall and floor tiles, grouting | Tiles are flat, joints are closed |
| 6. Finishing | Fixtures, furniture, lighting, ventilation, silicone seams | Everything works, no leaks, ventilation running |
Step 1: design and planning
Start from the existing situation: where do the risers run, how capable is the electrical installation, and how strong are the walls and floor? These facts decide what is feasible. A walk-in shower needs a different floor build-up than a bath because of the drain channel depth and the required fall. For moving drains, read our article on moving drains in a bathroom renovation.
Also fix the position of light points, switches and sockets. Wet rooms are subject to stricter safety rules, so have electrical work done by a qualified electrician. For a first budget estimate, use the renovation calculator.
Step 2: demolition and site preparation
Demolition strips tiles, fixtures and old pipes back to the structure. Corridors and living areas are shielded from dust and debris. Hidden defects only show once the finishes are gone: rotten timber, rising damp or cracks in the substrate.
Have a professional assess the substrate before rebuilding. An unstable or damp substrate later causes loose tiles and moisture problems.
Step 3: plumbing and electrics
In this rough-in phase, water, drainage and wiring are placed in their final positions. Pipes are concealed in the wall or floor. Concealed parts of the rain shower or toilet are fitted level and the pipes are pressure-tested before everything is closed up.
Drains need enough fall to avoid blockages. If you already have a slow drain, have it checked now, for example through our drain unblocking service. Wiring for lighting, heated mirror and fan follows the rules for wet rooms (AREI/RGIE).
Step 4: waterproofing and substrate
Tiles and grout are not waterproof. Water and vapour pass through joints and pores. A waterproofing membrane on the floor and walls of the shower or bath zone keeps moisture out of the building structure.
The membrane is applied with reinforcing tape in corners and seams. Respect the drying time the manufacturer specifies before tiling. This step is invisible once finished, so ask for photos of the membrane before the tiles go on.
Steps 5 and 6: tiling, ventilation and finishing
After tiling and grouting come fixtures, taps, shower screen, furniture and lighting. Joints and corners are sealed with mould-resistant silicone.
Ventilation is part of every bathroom renovation. Without effective extraction of humid air, vapour condenses on walls and ceiling and mould appears. Flanders and Brussels publish ventilation guidance for renovations, see the sources below. To hand the whole project to one team, see our bathroom renovation page or the role of a renovation contractor.
Comparing quotes without surprises
Only compare quotes that are built on the same basis. Use the table below as a checklist for each quote.
| Item | What you check |
|---|---|
| Demolition and debris removal | Included or charged separately? |
| Waterproofing | Which system, and for which zones? |
| Plumbing and electrics | What is replaced and what is kept? |
| Fixtures and tiles | Are brands and references named, or is it a provisional sum? |
| Ventilation | Which solution is planned? |
| Planning and payment | Which phases, drying times and deposits? |
For a fixed price based on your situation, ask for a quote after a site visit. See also our articles on small bathroom renovation cost and replacing a bath with a shower.
Fixed quote after a site visit
Alpha Services Benelux does the work with its own team, active since 2014. VAT BE 0541.320.178.
Request a quoteFrequently asked questions
How long does a bathroom renovation take?
It depends on the scope. Tiling can only start once the waterproofing is fully cured, so drying times shape the schedule. Expect several weeks from demolition to handover. Ask for a concrete schedule in the quote.
Do I need a permit to renovate a bathroom?
For interior work that changes neither the load-bearing structure nor the use of the building, an urban planning permit is usually not required. If you remove a load-bearing wall or alter the facade, for example for a ventilation duct, check with your municipality first.
Why is waterproofing under tiles necessary?
Tiles and grout are porous and let moisture through over time. Without a continuous membrane, water soaks into walls and floor, causing loose tiles, mould and structural damp. A membrane in the wet zones is therefore always laid before tiling.
In what order is a bathroom renovated?
First design and planning, then demolition, plumbing and electrics, waterproofing, tiling and finally fixtures, ventilation and finishing. Each step builds on the previous one and drying times must be respected before the next begins.
Can I demolish my old bathroom myself to save money?
You can, but pipes and electrical cables often run behind the tiles. Have a professional assess where they are first. Repairing a damaged main pipe or drain usually costs more than the saving on demolition.
Is there a subsidy for a bathroom renovation?
In Flanders, the Mijn VerbouwPremie covers preparatory sanitary and electrical work, under conditions. Check the current conditions on vlaanderen.be before you start, as the rules change regularly.
Sources
- Mijn VerbouwPremie voor voorbereidingswerken voor sanitair en elektriciteit — Vlaanderen.be
- Ventilatie bij renovatie — Vlaanderen.be
- Renoveren: thema's en kennisbank — Buildwise
- Ventilatie van een te renoveren woning — Leefmilieu Brussel