When a WA builder must be registered

The questions, in order

Building and Energy’s checklist asks three questions: does the work need a building permit, is it worth at least the value threshold, and is it inside the prescribed area of the state. Answer ‘no’ to any of the three and registration as a building contractor is not required. Work that meets all three can still be exempt, which is the second question below.

1. Does the work need a building permit?

   Building and Energy says a building permit is generally required for building work that includes:

   • constructing, erecting, assembling or placing a building or an incidental structure;
   • renovating, altering, extending, improving or repairing a building or an incidental structure;
   • assembling, reassembling or securing a relocated building or relocated incidental structure; or
   • changing ground levels, and site works, connected with any of the above.

   Permits are granted by the local government permit authority where the work will happen, and that authority is the one to ask whether yours needs one. If it needs no permit, it needs no registered builder.

2. Is it one of the exempt types of work?

   Building and Energy’s publication lists the types of building work for which registration is not required. The full list:

   • a permanent farm building on land used mainly for agriculture, where the building itself is for agricultural use
   • making a prefabricated or transportable building in a manufacturing yard
   • forming a parking area
   • forming outdoor sporting surfaces, with their fencing and lighting
   • walkways, and viewing or gathering platforms, that are not part of another building
   • a water tank that is not built into the structure of another building
   • an incidental structure, meaning one attached or incidental to a building, including a chimney, a mast, a swimming pool, a fence, a free-standing wall, a retaining wall, a permanent protection structure, or part of a structure
   • installing fire sprinklers, free-standing partitions, safety systems, glazing or timber decking
   • making and installing cabinets
   • second-fixing joinery work
   • owner-builder work that has an owner-builder approval from the Building Services Board

   Registration is also not required for an employee or subcontractor of a registered building contractor who is supervising the work, where that contractor is named as the builder on the building permit.

3. What is the work worth?

   Since 1 July 2026, a Class 10a building valued at less than $50,000 does not have to be built by a registered building contractor. Building work of any kind valued under $20,000 does not need a registered builder either, while most other building work valued at $20,000 or more that needs a building permit still does.

   Building and Energy words the line two ways. Its registration page sets it at work valued “$50,000 or more” for a Class 10a building and “$20,000 or more” for other work, as its Q&As do, but the same page’s application step says “more than $20,000” (or “more than $50,000 for Class 10a buildings”). Both wordings agree that work under $20,000 needs no registered builder; for a job valued at exactly $20,000 or $50,000, ask Building and Energy.

4. Is the block inside the prescribed area?

   The rules apply in an area the state prescribes, which takes in 122 of Western Australia’s local governments; in some areas of low population only the major town sites are included. Work in the exempt areas of the state does not need a registered builder.

Exempt from registration, not from a permit

A landscaper might build several things on that list: a fence, a retaining wall, a free-standing wall, a pool, timber decking. The exemption settles who may do the work, not whether it needs approval.

For a fence, a wall or a deck, the permit question goes to your local government permit authority, the body Building and Energy says you must ask. Patios and sheds have their own guide.

Practitioner and contractor

The Building Services (Registration) Act 2011 reserves particular building work for registered building practitioners and registered building contractors, and those are its two categories of registration.

After the first registration, practitioners and contractors renew every three years.

Your contract, registered builder or not

Building and Energy’s notice for homeowners counts landscaping as work associated with home building, alongside pools, sheds and pergolas. For contracts of that kind with a fixed cost between $7,500 and $500,000, your rights and protections come from the Home Building Contracts Act 1991, and they apply whether or not the builder is registered.

• Before you sign, the builder must give you a copy of the ‘Notice for the homeowner’, which sets out their legal obligations and your protections.
• The largest deposit a builder or tradesperson can require before starting is 6.5 per cent of the contract price. Below $7,500 or above $500,000 the Act does not apply, and there is no such limit.
• Apart from the deposit, upfront payments are not allowed, and making one can affect a claim under your home indemnity insurance.
• Home indemnity insurance is required for all building work that needs a building permit and is valued at more than $20,000; the builder must give you a copy of the certificate, and the page advises making no payment until the insurance is in place.
• An owner or builder who believes the contract or the Act has been breached can make a home building work contract complaint to LGIRS. The time limit is three years from the contract date, or from when the cause of action arose.