It's the first question almost everyone asks — and the honest answer is "it depends." A bathroom is one of the most complex rooms in a home: a small space packed with plumbing, waterproofing, tiling, electrical work and fine finishes, all of which have to be sequenced correctly. That complexity is exactly why two bathrooms of the same size can land at very different prices.
Rather than quote a single number that won't apply to your project, this guide explains the real factors that move the price, so you can budget with confidence and understand your quote.
What actually drives the cost
1. Size and layout
Bigger rooms use more materials and labour, but layout changes often cost more than size alone. Keeping plumbing fixtures roughly where they are is far cheaper than moving the toilet, shower or vanity to a new wall, which means relocating pipes and drainage.
2. Finishes and fixtures
This is the biggest lever you control. Tiles, tapware, the vanity, the shower screen and the toilet can range from budget to premium, and the difference adds up across the room. Imported stone, large-format tiles and designer brassware look stunning but cost more to buy and to install.
3. Waterproofing and tiling
Waterproofing is non-negotiable and code-regulated — it's what protects your home from hidden water damage for years to come. Tiling is labour-intensive, and intricate patterns, niches and large-format tiles all add time. This is skilled work where cutting corners is a false economy.
A bathroom is one of the few rooms where what you can't see — waterproofing, fall to the drain, substrate prep — matters as much as what you can.
4. Hidden conditions
Once the old bathroom comes out, things can surface: rotted timber, old or non-compliant plumbing, or previous waterproofing failures. A good builder allows for the likely and flags the possible, but some conditions are genuinely impossible to see until demolition.
5. Trades and coordination
A bathroom needs licensed plumbers and electricians, a waterproofer, a tiler and a builder to coordinate them in the right order. Smooth coordination keeps the job moving and the cost controlled; poor coordination causes delays that cost money.
Where the money goes
In most bathroom renovations, the cost splits roughly across demolition and prep, plumbing and electrical, waterproofing and tiling, fixtures and fittings, and the builder's coordination and finishing. Labour is typically the largest share — you're paying for skilled trades and careful sequencing, not just materials.
How to get an accurate figure
- Decide your priorities — what matters most: layout, finishes, or budget.
- Gather inspiration photos so the look is clear.
- Be realistic about selections before quoting — changing them later changes the price.
- Request a quote and, where helpful, a site visit so the scope is properly understood.
The most reliable way to know what your bathroom will cost is a proper quote based on your space and your selections — not a number from the internet.
Ready to start? Aurum Built handles bathroom & kitchen renovations across Sydney. You might also like our kitchen renovation checklist.
Renovations Bathrooms Budgeting