Where the Money Actually Goes in a Bathroom Renovation

A $30,000 bathroom, line by line

Here is a realistic breakdown of a standard North Shore main bathroom of about six square metres, taken back to frame and refitted, keeping the existing layout. Figures are indicative 2026 planning numbers, not a quote.

Line	Typical range	Share
Demolition, skip and disposal	$2,000 – $3,500	~9%
Plumbing (rough-in and fit-off)	$4,000 – $7,000	~18%
Electrical (rough-in and fit-off)	$1,500 – $3,000	~7%
Carpentry and wall framing	$1,000 – $2,500	~5%
Screed and floor falls	$1,000 – $2,000	~5%
Waterproofing	$1,200 – $2,500	~6%
Tiling labour	$5,000 – $9,000	~23%
Tiles and adhesive	$1,500 – $4,000	~9%
Vanity, toilet, tapware, screen	$3,000 – $7,000	~15%
Making good, paint, clean	$800 – $1,800	~4%

The pattern is the point. Labour is somewhere between 55 and 70 per cent of the job. Everything you can hold in your hand — the tiles, the tapware, the vanity, the toilet — is a minority of the total.

Why labour dominates

A bathroom is the most trade-dense room in a house. Six square metres pulls in four separate trades, and most of them come twice.

The plumber sets the wastes and water at rough-in, then returns weeks later to fit off. The electrician does the same with cables and fittings. Between those two visits the screed has to go down and dry, the membrane has to go on and cure, and the tiler needs several days to set out and lay.

Nobody works continuously. The room sits idle for days at a time, and that fragmentation is inherent to the sequence rather than a sign of a slow builder. It is also why the program runs three to four weeks for what looks like a week of visible work.

The consequence for your budget

Because materials are the minority, moving them moves the total less than people expect — in both directions.

Upgrading tapware from a mid-range set to a premium one might add $1,200 to a $30,000 job. That is four per cent for something you operate several times a day for fifteen years.

Downgrading tiles from $90 per square metre to $45 might save $1,300 on the same job. That is also about four per cent, for a surface that defines how the entire room reads.

Choosing a cheaper tiler could save $2,000 and cost you the room. Tiling is the longest skilled stage and the one everybody inspects at close range in good light. It is the worst possible place to economise.

The practical rule: spend where you touch, stand or depend, and save on the accessories.

Where upgrading actually pays

The shower mixer. You use it every day. A cheap mixer feels cheap every single time, and replacing it later means removing tiles.

The floor tile. You walk on it wet, barefoot. Slip resistance is a genuine safety property, not a specification detail, and it matters more in households with older or younger occupants.

The waterproofing. The one line where the cheapest option is unambiguously the wrong one. It sits under the screed and the tiles, so a failure cannot be reached without dismantling the finished room. The full explanation is here, but the short version is that a few hundred dollars of material and a few days of cure time protect everything above it.

Lighting at the mirror. Cheap, transformative, and it needs a cable at rough-in. A single ceiling downlight behind you puts your own shadow on your face every morning.

Where you can comfortably save

Towel rails and hooks. The mirror, unless it is a cabinet doing storage work. The toilet, where mid-range suits nearly everyone. Accessories generally. Off-the-shelf vanity carcasses instead of custom joinery, unless the dimensions are genuinely awkward.

None of those decisions are visible in the finished room in the way tiling and tapware are.

The lines people forget to check

Three items are legitimately part of the job and are frequently missing from cheaper quotes.

Rubbish removal and the skip. A bathroom strip-out generates real tonnage — tiles, screed, an old bath, wall sheeting. On the North Shore, skip placement can also mean a council permit where there is no off-street parking, which is common through Crows Nest and the harbourside Mosman streets.

Making good. The doorway architrave, the cornice, the paint where the old room ended and the new one begins. Small money, very visible when skipped.

The variation method. Not a cost, but the mechanism that determines every future cost. It should state how a discovery is priced and approved before work continues.

Variations, and which ones are fair

On a bathroom built before about 1990, something is usually found. Deteriorated framing where water has been tracking. Cast-iron waste at the end of its life. Previous unpermitted work. Asbestos-containing sheeting behind the tiles, which stops the job until it is assessed and removed by a separately licensed asbestos removalist.

Those are fair variations, and a quote that pretends they never happen is not being optimistic — it is being vague, and you will pay for the vagueness later with less negotiating room.

What is not fair is a variation for something that was visible at the measure. If the quote did not include the separate toilet that was obviously there on the day, that is a quoting error, not a discovery.

The two structural decisions that dwarf everything else

Every line above assumes the layout stays put. Two decisions sit outside that table and each can move the total more than every material choice combined.

Moving the drainage. Relocating the toilet, shower or basin waste means new falls. On a suspended timber floor it is tractable — the plumber works from below and the screed absorbs the rest. On a concrete slab, which is what you have in most of the walk-up stock through Chatswood and North Sydney, it means cutting concrete. That is noisy, slow, expensive and, in a strata building, a conversation with the owners corporation on top.

Taking down a wall. Combining a bathroom with an adjacent separate toilet is the highest-return change available in most post-war North Shore houses, because it converts two unusable rooms into one good one. But it brings its own chain: check whether the wall is structural, add a beam if it is, re-route any services inside it, then re-frame, re-sheet and re-tile a larger room.

Both changes are worth doing when the room warrants it. Neither should arrive as a surprise mid-job — they belong in the quote, priced, before demolition day.

A note on paying

Deposit limits for residential building work in NSW are capped under home building legislation, and the cap is lower than many people expect. Check the current figure with NSW Fair Trading before you pay anything, and treat a request for a large up-front sum as information about who you are dealing with.

Beyond the deposit, progress payments tied to completed stages are the normal and sensible structure — after rough-in, after waterproofing, after tiling, on completion. Paying ahead of the work removes the only leverage you have.

What to compare between quotes

Before comparing totals, confirm both name the fittings by brand and model, state the tile allowance per square metre, show waterproofing cure time in the program, include the skip and the making good, and set out the variation process in writing.

Two quotes that differ by $3,000 usually differ by more than $3,000 of scope. The cost bands will tell you whether either is plausible, and the FAQ covers the questions that come up next.