Before you start a bathroom renovation, decide the layout first because moving plumbing is costly and drives the rest of the project. Set a realistic budget with a 10-20 per cent contingency, choose fixtures and finishes early, and plan storage, lighting and ventilation as part of the design, not an afterthought. Confirm access during the build and get a written quote that spells out what is included, including waterproofing and trades.
01Lock in the layout before you sign anything
The layout is the biggest cost driver in a bathroom renovation. Moving a toilet, shower drain or bath waste usually means altering plumbing inside walls and floors, which adds labour and materials quickly. If the existing layout works, keep the main fixtures where they are and spend the budget on finishes and storage instead.
Before you commit, check clearances. You need enough space to open the shower screen, stand at the vanity, and use the toilet without your knees hitting the wall. A licensed plumber can confirm whether a wall-hung toilet is possible in your wall depth and whether waste pipes can be rerouted without major structural work.
- Keep toilet and shower in their existing locations where possible.
- Allow at least 900 mm clear space in front of a vanity and toilet.
- Check door swing and required landing space before choosing fixtures.
- Have a plumber inspect wall and floor cavity depth before choosing a wall-hung toilet.
02Budget priorities: spend where it is hard to change later
Prioritise waterproofing, plumbing rough-in and tapware bodies. A leak behind a tiled wall or a failed mixer cartridge means cutting into new tiles, so this is not the place to save money. Spend on a good toilet pan with a reliable flush and a properly installed shower screen that will not leak.
You can save on items that are easy to replace later, such as towel rails, mirrors and cabinet handles. Keep a 10-20 per cent contingency in your budget for surprises like rotted wall framing or old pipes that need replacement. If the budget is tight, avoid moving services and choose large-format tiles that are faster to lay.
- Waterproofing and plumbing rough-in are not places to cut corners.
- Choose a toilet with a good flush and easy-to-source spare parts.
- Allow 10-20 per cent on top of quotes for surprises in the wall or floor.
- Keep expensive wall tiles for a feature wall and use cost-effective large-format tiles elsewhere.
03Choose products before the build starts
Product lead times and rough-in requirements can delay a renovation if they are not sorted early. Tapware, vanities and toilets often need specific wall or floor positions before tiling begins. A wall-hung toilet needs a concealed cistern and carrier installed by a licensed plumber, while a Washlet bidet seat needs a power point and a nearby water supply.
If you are buying products yourself, check dimensions and compatibility with your renovator before ordering. A product that arrives damaged or does not fit can hold up the tiler. When a renovator supplies the products, they take responsibility for coordinating delivery and checking that everything works with the design.
- Confirm rough-in positions for tapware and shower mixers before tiling.
- Wall-hung toilets need a concealed cistern and carrier installed by a licensed plumber.
- A Washlet seat needs a dedicated power point and a nearby water supply.
- Buy from a showroom where you can see the finish and check stock before the rip-out.
04Plan storage, lighting and ventilation together
Storage in a bathroom should be decided before the walls are sheeted. A mirrored shaving cabinet can provide medicine and daily item storage without taking up floor space. Recessed shower niches are practical but need framing allowance before tiling, so decide on their size and position early.
Lighting and ventilation are often left to the end, but they affect the ceiling and wall layout. Use a mix of task lighting at the vanity and general lighting in the room, with light fittings rated for wet areas where needed. Install an exhaust fan ducted to outside, not just into the ceiling space. A window helps with natural light but is not a substitute for mechanical ventilation.
- Use a mirrored shaving cabinet to gain storage without floor space.
- Recessed shower niches need framing allowance before tiling.
- Install an exhaust fan ducted to outside, controlled separately from the light.
- Position task lighting at the vanity, not just a single centre ceiling light.
05Prepare for access during the works
A bathroom renovation is disruptive, and access needs to be worked out before demolition starts. Agree on which entrance trades will use, where materials will be stored, and whether the toilet will stay connected during the project. If this is your only bathroom, you will need an alternative arrangement for washing and using the toilet, so plan for that early.
Protect the rest of the house from dust and foot traffic. Lay drop sheets or self-adhesive floor protector on carpets and timber floors along the access path. Keep pets away from the work area and make sure the site can be locked at the end of each day.
- Agree on an access route and working hours before the build starts.
- Protect carpets and timber floors with drop sheets and self-adhesive floor protector.
- If it is your only bathroom, plan for a portable toilet or staying elsewhere.
- Keep pets away from the work area and electrical leads.
06Get a written quote that covers the detail
A written quote after a physical measure is the only way to know what you are paying for. It should itemise demolition and waste removal, waterproofing to AS 3740, plumbing and electrical rough-in, tiling, fixture installation, fit-off and cleaning. Check whether the quote includes supply of products or if you are expected to provide them, and ask how variations are handled if hidden problems appear.
Baroco Interior Innovations provides written quotes after a measure and has a showroom at 21/105-111 Ricketts Road, Mount Waverley, where you can view and choose products for your renovation. If you are supplying your own installer, you can also buy products from the showroom.
- Ask for a written quote after a physical measure, not just a phone estimate.
- Check the quote lists waterproofing, plumbing, electrical, tiling and fixture installation.
- Clarify who supplies the toilet, vanity, tapware and tiles.
- Confirm the process for variations if hidden problems are found.
Planning this for your home? See how we design, supply and build it, or visit the Mount Waverley showroom.
Bathroom renovations · Try the AI bathroom previewRelated questions
Still unsure? Call 0426 520 859 and talk to someone who actually installs this stuff.
Do I need a building permit for a bathroom renovation?
Whether you need a permit depends on the scope. Replacing existing fixtures in the same location often does not require one, but moving plumbing or altering walls might. Have your renovator or local council check before work starts.
Is waterproofing mandatory?
Yes. Waterproofing must comply with AS 3740 and be done by a licensed waterproofer or tradesperson. Do not tile until the waterproofing has cured and passed inspection.
Can I buy my own toilet and vanity?
Yes, but coordinate with your renovator. Check dimensions, rough-in distances and whether a power point is needed for a Washlet seat. Products supplied by the renovator may be easier to manage if there is a defect or delay.
What if I only have one bathroom?
Plan for an alternative toilet and washing arrangement before demolition starts. A portable toilet or staying with family can reduce stress, and your renovator should give you a realistic programme before work begins.
