How to budget for a bathroom renovation without blowing it

Why bathroom budgets blow out

The most common reason a bathroom renovation costs more than expected is that the scope was not clear before work started. An approximate quote based on a phone call or a rough sketch leaves room for assumptions on both sides, and those assumptions show up as variations once the walls are open.

The second most common reason is a change of mind mid-build. Upgrading tiles after they have been ordered, moving a toilet position after the plumbing rough-in, or adding a heated towel rail after the electrical is done all add cost because they undo work that has already been completed.

A fixed-scope written quote that names every inclusion, and a selections process that locks in materials before site work begins, are the two most effective budget controls available to a homeowner.

Start with how much you can spend, not how much it costs

Work out what you can afford before you start comparing quotes. A bathroom renovation in Sydney typically ranges from $18,000 to $50,000 or more, depending on the room size, the scope and the finish level. That is a wide range, and trying to price a bathroom without a budget is like shopping without knowing what is in your account.

A common guideline is to keep the renovation cost within five to ten percent of the property value. For a home worth $1.2 million, that suggests a bathroom budget of $60,000 to $120,000 across all wet areas — not per room. If the home is worth $800,000, the range is tighter.

The budget should include a contingency of 10 to 15 percent. This is not padding — it is a realistic allowance for what may be found behind the walls, especially in older homes.

Where the money goes

In a typical full bathroom renovation, labour and trades account for roughly 40 to 50 percent of the total cost. This covers demolition, plumbing, electrical, waterproofing, tiling and installation of fixtures. Materials — tiles, adhesives, membranes, cement sheet — make up 15 to 20 percent.

Fixtures and fittings — the vanity, tapware, toilet, shower screen, mirror, towel rails — account for 25 to 35 percent. This is where the finish level has the biggest impact. A basic vanity and chrome tapware cost a fraction of a stone-top vanity with brushed brass fittings.

The remaining 10 to 15 percent is contingency. In practice, this covers the things that only become visible at strip-out: old plumbing that needs replacing, water damage in the subfloor, or non-compliant waterproofing from the previous renovation. We cover these in more detail in our hidden costs guide.

How to compare quotes without being misled

The cheapest quote is not always the cheapest renovation. A low quote that excludes items the others include will cost the same or more once the variations are added. The question is not "which quote is lowest" but "which quote includes the most for what I need." Our guide to comparing renovation quotes covers what to look for in detail.

Ask each renovator to itemise what is included: demolition, disposal, plumbing, electrical, waterproofing, tiling, fixtures, painting, clean-up. If an item is missing from one quote, it does not mean it is free — it means it will be an extra.

Check whether the quote is fixed or provisional. A fixed-scope quote names the price for a defined set of inclusions. A provisional quote estimates costs that may change. Both are legitimate, but they manage risk differently, and you need to know which one you are signing.

Selections: lock them in early

Tiles, tapware, the vanity, the toilet, the shower screen, lighting — all of these should be selected and confirmed before the renovation starts. Changing a selection after the build is underway almost always adds cost, because it changes the scope that the quote was based on.

If you are unsure about a selection, say so during planning. A good renovator will walk you through the options within your budget and help you finalise choices before the contract is signed.

ETR's written quote ties the selections to the scope and the price. If a selection changes, the price adjustment is clear and agreed before the work is affected.

Where to spend and where to save

Spend on waterproofing, plumbing and the things you cannot see or reach once the room is finished. These are the items that cause expensive problems if they fail, and the cost difference between adequate and good is small compared to the cost of fixing them later.

Spend on the fixtures you touch every day: the showerhead, the tapware, the toilet flush. Cheap fittings feel cheap every morning.

Save on decorative items that are easy to change later: towel rails, mirrors, accessories, paint colour. These can be upgraded without opening a wall. Save on tile upgrades that add visual complexity without adding durability — a well-laid neutral tile lasts as long as an expensive pattern tile and dates less.

How a written scope prevents surprises

The single most effective way to hold a bathroom renovation budget is a written scope that names every inclusion, every exclusion, every allowance and every condition. If it is in the scope, it is in the price. If it is not in the scope, it is not in the price.

A written scope also names how unexpected finds are handled — what happens if the plumber finds corroded pipes, or the tiler finds water damage in the substrate. The best time to agree on this is before the contract is signed, not when the builder is standing in a half-demolished bathroom.

ETR provides a fixed-scope written quote after the free on-site measure. The quote separates the inclusions, the exclusions and the process for handling anything found at strip-out. The price is the price unless the scope changes.

Frequently asked questions