Ask five Queensland builders what a bathroom costs and you will get five answers, because a bathroom renovation is not one job. It is several licensed trades working in sequence in the smallest, wettest, most closely regulated room in the house.
There is no headline price on this page, and the reason is instructive. The Australian Bureau of Statistics counts only renovation work that needed a building approval, valuing approved alterations and additions to homes nationally at $1,288 million in July 2026, seasonally adjusted. Most bathroom refits never appear in that figure, so no reliable public average exists. Here is what actually moves the cost instead.
What actually drives the cost of a bathroom renovation?
Six decisions set the price before a single tile is chosen.
| Decision | Why it moves the cost |
|---|---|
| Like-for-like, or a new layout | The biggest fork in the road. Keeping the layout keeps the drainage where it is |
| Moving plumbing | Drainage needs fall. On a slab that means core drilling or a raised floor; on a timber floor, working around joists you cannot cut |
| Waterproofing extent | Membrane system, height and penetrations, set by the Code rather than by taste |
| Tiling area and format | Large-format and stone tiles need flatter substrates and slower setting. Floor-to-ceiling versus splashback height is the quietest multiplier here |
| Fixtures and tapware | The widest spread of any line, and the one you control most directly |
| What is behind the wall | Rot, old copper, undersized waste, non-compliant framing, asbestos sheeting. Older Sunshine Coast homes hide all of it |
What is the most expensive part of a bathroom renovation?
For most Queensland bathrooms it is labour rather than product, and within labour it is anything that moves water. Relocating a toilet, shower waste or floor waste triggers a chain: demolition, drainage alteration, substrate rebuild, a fresh waterproofing membrane, then screeding and tiling to new falls. Each step brings a different licensed trade back into a room only one of them can occupy at a time.
Fixtures feel expensive because you see the price tags, but a premium mixer set is a single line item. A moved drain rewrites the schedule. The one lever that reliably reduces cost is keeping the fixtures where they are.
What is a realistic budget for a bathroom renovation?
Build it from the room, not from an average. Queensland contract law gives you useful brackets, because the rules change as the price rises. The Queensland Building and Construction Commission sets out that domestic building work under $3,300 needs no written contract by law, that work priced from $3,301 to $19,999 requires a Level 1 contract, and work at $20,000 and over requires a Level 2 contract, which must include the QBCC Consumer Building Guide, a start date and the statutory warranties.
Where your own job lands in those brackets is set by the six drivers above, not by an average, and the contract level follows the price rather than the other way round. Ask which level your builder is contracting under, then check the document actually contains what that level requires. Ask for itemised quotes separating demolition, plumbing, waterproofing, tiling, electrical, fixtures and a stated contingency. A quote with one number and no breakdown cannot be compared with anything.
Does a bathroom renovation need building approval in Queensland?
Usually not, but the exception is common enough to check first. A refit that stays inside the existing walls and changes nothing structural generally does not need a development permit for building work. The moment the scope touches structure, whether that is altering a load-bearing wall, cutting a new window or changing the floor structure, you are into assessable building work and you need a building certifier.
Noosa Shire Council states that most types of building work require a development approval, and lists renovations and alterations among them. The QBCC is equally direct about who carries the risk: it is your responsibility as a home owner to make sure the right building approvals are in place before work starts, even if you have hired a builder. The certifier assesses the plans, inspects at mandatory stages and issues certificates of inspection.
Which council you deal with depends on where you live. Noosa Shire Council administers the Noosa Plan 2020 across the Noosa-area suburbs; everywhere else in our service area, from Coolum Beach to Pelican Waters, sits with Sunshine Coast Council. See our guide to renovation approvals in Noosa Shire.
Does the plumbing in a bathroom renovation need council approval?
Most of it is notifiable work rather than permit work. The QBCC defines notifiable work as plumbing and drainage work a licensed plumber or drainer can carry out without a local government permit or mandatory inspections, and it expressly includes installing new or relocating fixtures such as toilets, showers and basins. Your plumber must register it with the QBCC using Form 4 within 10 business days of issuing an invoice. Plumbing and drainage work associated with new construction is permit work, which does need council approval and inspection. Ask which category your job falls into before it starts, and ask for the Form 4 confirmation afterwards.
What does waterproofing to AS 3740 actually require?
This is where bathrooms fail, and it is the one part of the budget nobody should trim. Part 10.2 of the National Construction Code Housing Provisions requires building elements in wet areas to be waterproof or water resistant and to comply with AS 3740, Waterproofing of wet areas in buildings. Inside the shower that means the floor is waterproof including any hob or step-down, the walls are waterproof to a minimum of 1800 mm above the floor substrate, wall junctions and joints are waterproof for at least 40 mm either side, wall-to-floor junctions are waterproof, and every penetration within the shower area is waterproof. Those are minimums, and falls, drainage and substrate preparation all have to work with the membrane, which is why the sequence on site matters as much as the product in the tin.
Who is allowed to waterproof a bathroom in Queensland?
Waterproofing is its own QBCC trade contractor licence class. Building work valued over $3,300 requires a QBCC licence, and plumbing and drainage work requires one at any value. Expect a licensed waterproofer, plumber and electrician, with a licensed builder coordinating them. Check every one on the QBCC register before you sign.
Do I need a written contract and home warranty insurance?
Yes, on almost any full bathroom. The QBCC states that most residential building work in Queensland valued at more than $3,300 including materials, labour and GST must be covered by the Queensland Home Warranty Scheme, and that the contractor pays the premium, based on the insurable value of the work. If a quote is priced to sit just under $3,300, understand what you are giving up.
Does living on the coast change the specification?
It changes the hardware. Salt air is unforgiving on tapware finishes, shower screen fittings, hinges and exhaust fans. Whether a fitting holds up in Coolum Beach or pits and seizes early is decided at quoting stage, not in maintenance later.
Working with Roebuck Concepts
Roebuck Concepts is a licensed Queensland builder at Unit 1/18 Lomandra Place, Coolum Beach, holding QBCC licence 15280811 and a member of Master Builders Queensland. At the 2025 Master Builders Queensland Sunshine Coast Housing & Construction Awards on 15 August 2025 at The Events Centre, Caloundra, our Grandview project at Coolum Beach won Home Renovation/Remodelling Project over $1 million, Best Residential Swimming Pool and Best Use of Innovation.
Bathrooms are usually one part of something larger for us. See our renovation work across the Sunshine Coast, the Grandview Drive project, or our guide to what a major renovation costs on the Sunshine Coast. To have a bathroom priced properly, book a consultation or call 0477 333 386.