Usually no, sometimes yes, and only a building surveyor can settle it for your house. This page is the one place on the site where the Victorian rules are written out in full. Everything else here points back to it. What follows is what pulls a bathroom into permit territory, who is allowed to hold the tools, what the paperwork has to say, what can be asked of you before work starts, and what protection is still standing if a problem shows up in year four.

What turns a bathroom into permit work?

All building work in Victoria needs a building permit unless Schedule 3 of the Building Regulations 2018 exempts it. A like for like bathroom renovation that stays inside the walls already there generally sits within those exemptions. Each exemption carries conditions, though, and the only person who can sign off that a particular job meets them is a building surveyor. Anyone answering this over the phone without seeing the house is guessing.

The work that pulls a bathroom across the line is structural or dimensional:

work affecting the structural soundness of the building
a change in floor area or in height
underpinning or re footing
removing or altering a loadbearing element, such as taking out the wall between the bathroom and a bedroom to make the room larger

Waterproofing a wet area is not a trigger on its own. Neither is swapping the fixtures, relining the walls or retiling, where the room keeps its size and the structure is left alone.

In practice, a Cranbourne East or Cranbourne North ensuite refitted in place rarely needs a permit. A township house where a bedroom corner is turned into a second wet area, with a wall taken out or a new opening formed, is a different question and needs the surveyor to look at the drawings.

Who issues the permit in the City of Casey?

A private building surveyor appointed by the owner issues it, not the council. You engage the surveyor, the surveyor assesses the documents, issues the permit and carries out the mandatory inspections. Council involvement in a job this size runs to matters like asset protection and a permit for a skip or bin standing on the road or the nature strip. Those fees move from year to year, so they are confirmed at quoting time rather than quoted from a web page.

Who is allowed to do the work?

Trade	Requirement
The builder	Once the work is worth more than ten thousand dollars it has to be carried out by a registered building practitioner. Two classes cover it: Domestic Builder (Unlimited), and the narrower Domestic Builder (Limited to bathroom, kitchen and laundry renovation), which allows wet area work provided it stays inside the external walls, the floor and the ceiling already standing
The plumber	Holds a plumbing licence. A compliance certificate has to be issued for plumbing work worth more than seven hundred and fifty dollars, and for any below ground sanitary drain or gas work whatever its value
The electrician	The work is carried out by a Licensed Electrical Worker engaged by a Registered Electrical Contractor, and a Certificate of Electrical Safety is issued for it
The asbestos removalist	Taking bonded asbestos sheet out of a pre 1990 wet area is licensed work, and the material is identified first by a NATA accredited laboratory

The regulator for building and for plumbing in Victoria is the Building and Plumbing Commission. Builders hold registration. Plumbers and electricians hold licences. The two words are not interchangeable, and a quote offering you a licensed builder was written by somebody who has not read the rules they work under.

When a written contract becomes compulsory

Add labour, materials and GST together. Past ten thousand dollars, a written major domestic building contract stops being optional, and nearly every full bathroom clears that mark. The contract sets out the scope, the fixed price, the payment stages, the start and completion arrangements, and the process for varying the work. A variation agreed on site and never written down is the single most common source of argument at handover.

How much can be asked for before work starts?

Deposits are capped by statute. Where the contract price is under twenty thousand dollars the deposit cannot exceed 10 per cent. At twenty thousand dollars or above it cannot exceed 5 per cent. Nothing past the deposit should be paid before work begins.

Payments after the deposit belong against stages you can stand in the room and look at: rough in complete, waterproofing complete, tiling complete, and the balance at handover. A payment schedule tied to calendar dates instead of finished stages gives you nothing to withhold when a trade does not turn up.

The warranty that applies from 1 July 2026

On 1 July 2026 the First Resort Home Warranty Scheme took over from Domestic Building Insurance. The scheme reaches domestic building work valued above twenty thousand dollars where the home is no taller than three storeys. Cover against defective work runs for six years from completion, and assistance is capped at four hundred thousand dollars for the home.

The insurance product it replaced, and the sixteen thousand dollar threshold that went with it, now reach only contracts dated before that changeover. A bathroom priced below the scheme threshold gets none of that cover, whatever a salesperson implies.

The 10 year statutory warranty is a separate thing again. It is the limitation period for bringing a building action in Victoria, and it stands as a legal right regardless of what appears on a renovator’s own paperwork. A lifetime waterproofing guarantee is a private promise that lasts exactly as long as the business behind it.

What the waterproofing standard requires

Waterproofing is carried out to AS 3740, current edition 2021, which the National Construction Code calls up. Victoria adopted NCC 2025 on 1 May 2026. Shower walls are taken to 1800 mm above the floor substrate, a height set by the Code rather than by the standard itself. The membrane is then given the manufacturer’s cure time before anything is laid over it, which is why there are empty days in the middle of the program on how long a bathroom renovation takes.

Asbestos rules on a pre 1990 house

Bonded asbestos cement sheet was ordinary lining material in Australian wet areas for decades. It turns up in the wall sheet, the ceiling sheet, the backing board under the tiles, the floor vinyl and the adhesive holding that vinyl down. Treat a pre 1990 Cranbourne bathroom as containing it until a NATA accredited laboratory reports otherwise.

Sampling comes before demolition, not after a tradesperson has already put an angle grinder through a wall. Removal is licensed work with its own disposal requirements, and a clearance follows the removal. Keep the clearance paperwork with the house records.

Certificates to hold at handover

The plumbing compliance certificate. The plumber has five days to issue it and five days to lodge it, and it carries six years of insurance from the date it was issued.
The Certificate of Electrical Safety covering the electrical work.
Evidence that the membrane went on to AS 3740, naming the product and the applicator.
Where the job needed a permit, the occupancy permit or certificate of final inspection from your building surveyor.
Any asbestos clearance documentation, where removal took place.

Ask for the set on the day, while the trades are still engaged and interested. These are the documents you produce if a problem appears in year four, and the ones a buyer’s conveyancer asks about when the house is sold.

The order a first timer should work in

Settle the scope, including whether any wall is moving.
Get written quotes and read them against the checklist on choosing a bathroom renovator.
Where a wall, the floor area or a loadbearing element is involved, engage a private building surveyor before signing anything.
Sign the contract and pay no more than the capped deposit.
Confirm asbestos sampling in writing for any house built before 1990.
Keep every variation in writing, with a price on it.
Collect the certificates at handover and file them with the house records.

Band by band prices for each of these scopes are on bathroom renovation cost in Cranbourne. To have a specific house assessed against these rules, send the details through the quote form.

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Do I need a building permit for a bathroom renovation?