Bathroom Renovation Compliance in Queensland: Licensing, Waterproofing and What Your Builder Must Certify

The scheme applies to most residential building work valued at more than $3,300, counting materials, labour and GST together. That threshold catches essentially every full bathroom renovation and plenty of partial ones.

The premium is paid by the licensed contractor and must be built into the contract price. It is not a surcharge to be billed to you separately as an extra. If a quote lists home warranty insurance as an additional line the homeowner pays on top, that is a conversation to have before signing.

Owner-builder work and work under the threshold are exempt. That exemption is why some very cheap quotes exist: an unlicensed operator working under the radar carries no insurance, so if the job is abandoned half-finished or the shower leaks into the hallway in three years, there is no scheme sitting behind it. The cover exists precisely for non-completion and defective work, which are the two failures homeowners least expect and can least afford.

Practical check: once the contract is signed and the premium paid, you should be able to confirm the policy exists rather than take it on trust. Ask your contractor for the notification and keep it with the contract.

Waterproofing of internal wet areas must be carried out by an appropriately licensed person. It is not general labouring work, and it is not a task for whoever is on site that morning with a spare afternoon.

The governing standard is AS 3740:2021, referenced by the National Construction Code, and it covers shower floors and walls, bathroom floors, the area behind a bath, wall and floor junctions, and every plumbing penetration through the membrane. NCC 2022 tightened several requirements, including full waterproofing of shower walls and floor waste gradients set between a minimum of 1:80 and a maximum of 1:50.

That fall range is worth understanding as a homeowner, because it is where a lot of arguments start. Too flat and water sits on the floor and creeps toward the door. Too steep and tiles look wrong, large-format tiles will not sit flat, and a shower screen will not seal properly against a sloping base. Getting the screed inside that window is a skilled job, and it is one of the reasons a walk-in shower with a channel drain needs the fall planned before the screed goes down rather than corrected afterwards. If you want the technical detail on how the membrane itself is built up, our guide to long-lasting bathroom waterproofing and the walk-in shower design and drainage guide cover it. This page is about who is permitted to do it and what proves they did.

Brisbane makes the standard less academic than it sounds. A south-side bathroom with one small louvre window, in a summer where humidity sits high for weeks and a storm dumps rain through an afternoon, dries slowly. A membrane defect that a drier climate might tolerate for years shows up here as swollen skirting, dark grout at the base of the shower wall, or the smell of damp in a linen cupboard that shares a wall with the shower. Those are the early signs of waterproofing failure worth learning to spot.

In Queensland, the Form 43 aspect certificate is the document a QBCC licensee completes to record that an aspect of building work, waterproofing included, complies with the building development approval that work was carried out under. It names the licensed person responsible for that aspect of the work, and only the licensee who actually did the work can sign it.

Its value is almost entirely in the future. On the day of handover, the bathroom looks finished either way. The certificate matters when you sell the house and a buyer’s building inspector asks what was done, when an insurer asks whether wet-area work was carried out to standard after a water damage claim, or when a leak appears in year four and the question becomes who is accountable. Without it, you have a tiled room and a story.

One point is worth understanding, because a lot of online advice gets it wrong. A Form 43 is issued where the waterproofing forms part of work carried out under a building development approval. Plenty of like-for-like bathroom renovations proceed without a building approval, and in those cases no Form 43 is generated. On its own that is not a warning sign.

What you should insist on either way, in writing, is the membrane system used, the areas it was applied to, who applied it and their licence details, and the product warranty. Keep whichever document you receive with your contract, and store a scan somewhere that survives a computer replacement. A builder who cannot tell you in writing what was applied and by whom is a different problem entirely.

Usually not, if you are replacing what is already there. A like-for-like refit inside an existing bathroom, new tiles, new fixtures in the same positions, a new vanity, a shower rebuilt in the same footprint, generally proceeds without a building approval from a private certifier. The waterproofing and plumbing rules still apply in full regardless.

Approval enters the picture when the work goes beyond a refit. Common triggers include removing or altering a load-bearing wall, changing the size or position of a window or external opening, extending the bathroom footprint into another room or outward, work on a house with a heritage or character overlay, and structural changes to floor framing. Some plumbing work is notifiable, meaning your licensed plumber must lodge it with the regulator; relocating a toilet, adding a new fixture, or altering drainage is a different matter from swapping a tap onto existing pipework.

The honest answer for most homeowners: if you are moving walls, moving drainage, or touching structure, ask early. Councils across Brisbane, Logan and Redland differ in how their local planning overlays apply, and a character or demolition control overlay on a pre-1947 house changes what you can do to external walls. This is one of the reasons an older Brisbane home needs its compliance questions settled before demolition rather than during it, along with testing for asbestos in wall and floor linings, which is a competent-person job and, where removal is required, licensed work.

A defined scope, in writing, with the compliance points named. Vague quotes are where disputes are born, because a single line reading “renovate bathroom” leaves every inclusion arguable later.

Look for these specifics before signing:

1. The licensed entity’s legal name and QBCC licence number, matching what you searched.
2. A scope that lists what is included and, just as importantly, what is excluded.
3. Who is responsible for waterproofing and confirmation that a certificate will be issued.
4. How variations are priced and approved, in writing, before the extra work happens.
5. Payment stages tied to progress, with a deposit within legal limits rather than a large upfront sum.
6. The warranty terms and what they cover.

Fixed-scope quoting exists to close those gaps. Our quotes define the scope and the inclusions up front so the price is not a moving target once the walls are open, and the common renovation mistakes we see most often start with a quote that never said what it covered.

At specific, visible checkpoints, not as paperwork produced at the end. Rough-in plumbing and electrical happen before wall sheeting, so anything wrong there is expensive once tiles are on. The screed and its fall are set before the membrane. The membrane goes on and must cure before anything is laid over it, with the cure time driven by the product data sheet and site conditions rather than the tiler’s schedule. Then tiling, then fit-off.

The sequence is the compliance. A builder who tiles over an uncured membrane, or who cannot tell you who applied it, has skipped a step you cannot see afterwards. Our week-by-week guide to the build walks through what each stage should look like from the homeowner’s side of the door.

Running licensed trades in-house is how we keep those checkpoints tight: carpenter, plumber, electrician, waterproofer, tiler, glazier, plasterer and painter, with more than 50 years of combined experience across the team and 20 years in the industry for owner Shannon Jones. It means the waterproofer is not a subcontractor squeezed between two other jobs on a day the screed is not ready.