How to Plan a Bathroom Renovation, Step by Step

1. Start with what is wrong now

Before looking at a single tile, write down what does not work in the room you have. Be specific:

• Is there a leak, a stain on the ceiling below, loose tiles or a musty smell?
• Is the shower too small, or is the bath rarely used?
• Is there nowhere to put things, or not enough bench space?
• Does the room queue up in the morning?
• Is the lighting poor, or does the mirror fog every time?

Signs of water damage change the project from an upgrade to a repair. They mean the room needs to come back to the frame and be properly waterproofed, whatever it looks like on the surface.

2. Decide who the room is for

A main bathroom shared by three children has a different brief from an ensuite for two adults or a powder room for guests. Think about:

• Who uses it and when. Two people at once suggests double basins or a separate toilet.
• Young children. A bath is often still worth keeping somewhere in the house.
• Ageing in place. A level-entry shower, wall reinforcement for future grab rails and a slip-resistant floor cost far less to include now than to add later.
• Resale. If you plan to sell within a few years, broadly appealing finishes usually beat a very personal scheme.

3. Set a budget with a contingency

Work out what you are comfortable spending, then hold part of it back. Old bathrooms hide things: water-damaged floor sheeting, rotten framing, tired pipework and, in homes built or renovated before about 1990, possible asbestos. Many people keep around ten per cent aside, and more for an older house.

Decide early where the money matters most to you. Waterproofing, drainage and ventilation are not places to economise. Tiles, tapware and accessories are where you have the most choice.

4. Settle the layout

The layout drives cost more than almost anything else. The cheapest plan keeps the toilet, shower and vanity wastes where they are. Moving them means new drainage, and on a concrete slab that can mean cutting the floor.

Practical points to check on a plan:

• Shower size. Around 900 × 900 mm is workable; 1,000 to 1,200 mm in one direction feels far more generous.
• Walk-in versus hob. A hobless, level-entry shower needs the floor set down or built up to get the fall right. Ask whether your floor allows it.
• Clearance in front of the toilet and vanity. You need enough space to stand and move comfortably, and a door that does not hit anything when it opens.
• Bath or no bath. If the house has another bath, the space may work harder as a larger shower.
• Storage. A shower niche, drawers rather than doors in the vanity, and a recessed mirror cabinet all save bench space.

Draw it to scale, even roughly, with the door swing marked. It shows problems quickly.

5. Plan ventilation, lighting and power

These are easy to forget and hard to fix later:

• An exhaust fan ducted to the outside, not into the roof space.
• Good general lighting plus light at the mirror, so faces are not in shadow.
• Power points where you actually need them, such as inside a mirror cabinet for a toothbrush or shaver.
• Heating if you want it: a heated towel rail or underfloor heating needs to be wired at rough-in.

Electrical work must be done by a licensed electrician.

6. Choose your selections

Make a list of every item: floor and wall tiles, grout colour, vanity and basin, tapware, shower rose, toilet, shower glass, mirror or cabinet, towel rails, lighting and the exhaust fan. For each, record the size, finish and quantity.

A few tips:

• Match finishes across tapware, rails and accessories, ideally from one range.
• Check slip resistance of floor tiles for wet areas; ask the supplier for its rating.
• Buy extra tiles, usually around ten per cent for cuts and breakage, and keep a few for future repairs.
• Confirm lead times. Imported tiles and made-to-size vanities can take weeks. Our guide on how long a bathroom renovation takes lists typical lead times for each item.

7. Check approvals and rules

Most internal bathroom renovations that do not alter the structure do not need a formal approval, but the rules vary by state and council. If you plan to remove a wall, change a window, extend the room or you live in a heritage-listed home, check with your council or a private certifier before committing. In a strata building, check the by-laws and seek owners corporation approval for work affecting waterproofing or plumbing. Plumbing and electrical work must be done by licensed trades, waterproofing should be done by an appropriately licensed or qualified applicator, and a waterproofing certificate should be issued when the membrane is complete.

8. Get comparable quotes

Give every builder the same brief: the layout, the list of selections or allowances, and what you expect to be included. Then compare:

• Is the full membrane included and certified, or only the shower?
• Is there a tile allowance, and is it realistic for what you chose?
• Are waste removal, site protection and an asbestos test included?
• Are glass, the exhaust fan and lighting in the price?
• What is the payment schedule, and does it follow completed stages?

Check that the builder holds the right licence for your state and, where it applies, the required home building insurance. The cheapest quote is often the one with the most left out.

9. Plan for living through it

Decide where everyone will shower while the room is out of action. Think about trade parking, where a skip or bin will sit, protection for floors and stairs, and dust. If you are renovating two bathrooms, keep one working at all times, or do them together while staying elsewhere.

10. Lock it in before demolition

Finalise every selection, have long-lead items delivered and checked, sign a written contract and agree a program with the builder. The fewer decisions left once the old room comes out, the faster and calmer the job.

Next steps

Once you have a brief, see our full bathroom renovations and ensuite renovations services, and the bathroom renovation cost guide for broad budget bands. For the order we work in on site, read how we renovate. If you are in Castle Hill or the Hills District, we can measure the room and turn your plan into an itemised price.