Builders manage and carry out the construction of new homes, extensions, renovations, and structural alterations. In Australia, a licensed builder is both the project manager and the responsible party for ensuring the finished structure meets the National Construction Code, relevant Australian Standards, and local council requirements. They coordinate subcontractors — from concreters and bricklayers to plumbers and electricians — and are accountable for the structural integrity and quality of the entire build. Homeowners typically engage a builder for new home construction, major renovations, extensions, knock-down rebuilds, and structural work such as removing load-bearing walls. Builders must hold Home Warranty Insurance for residential work above state-specific thresholds, giving homeowners recourse if defects appear after completion.

Department of Mines, Industry Regulation and Safety — Regulatory Overview

Department of Mines, Industry Regulation and Safety is Western Australia's principal regulator for the building and construction industry, responsible for licensing all builders who perform regulated work in the state. The Department of Mines, Industry Regulation and Safety issues and renews licences, sets minimum requirements for licensees, investigates complaints, and takes disciplinary action against non-compliant operators.

As of February 2026, Department of Mines, Industry Regulation and Safety oversees 20,449 licensed builders across Western Australia, covering 4 licence classes. This represents one of the most comprehensive licensing regimes in Australia, designed to protect consumers and maintain industry standards.

Builder Licence Types in Western Australia

Licence Type	Description
Building Contractor Registration — Unrestricted	All types of residential and commercial building work
Building Contractor Registration — Group 1 (Houses)	Residential building work up to 3 storeys
Building Contractor Registration — Group 2 (Alterations)	Alteration and renovation work on existing buildings

Requirements to Become a Licensed Builder in Western Australia

Diploma of Building and Construction (CPC50220) or equivalent
Minimum 5 years industry experience (3 years supervisory)
Home indemnity insurance for residential work over $20,000
Public liability insurance
Construction induction card (White Card)

Builder Licence Costs in Western Australia

Application Fee

$785 for building contractor registration

Renewal Fee

$496 triennially

Renewal Period

3 years

Penalties for Unlicensed Work

Unregistered building work in WA carries fines up to $50,000 for individuals. DMIRS can also issue building remediation orders, stop-work orders, and prosecute offenders.

Exemptions — Builder Work You Can Do Without a Licence

Work valued under $7,500 (non-structural, non-specialist)
Owner-builder work with an Owner Builder Approval (for work over $20,000)
Minor maintenance, repairs, and painting
Garden landscaping not involving structures

How to Verify a Builder in Western Australia

Verifying a builder's licence in Western Australia is straightforward and should be done before engaging any tradesperson for work. You can use TradieVerify's free search tool to instantly look up any Western Australiabuilder by name, licence number, or business name. Alternatively, you can search directly through Department of Mines, Industry Regulation and Safety at https://www.demirs.wa.gov.au.

When verifying, confirm: (1) the licence is current and active, (2) the licence class covers the type of work you need, (3) there are no conditions or restrictions on their licence, and (4) there is no disciplinary history. A legitimate builder will have no hesitation providing their licence number for verification.

How to Hire a Builder in Western Australia

1
Verify their Home Warranty Insurance is current
For residential building work above the state threshold (e.g. $20,000 in NSW, $16,000 in VIC), the builder must hold Home Warranty Insurance (also called Home Building Compensation in NSW). Ask for the certificate before signing — it protects you if the builder dies, disappears, or becomes insolvent before defects are rectified.
2
Ask to see their QBCC or equivalent financial standing
In Queensland and several other states, builders must meet minimum net tangible asset requirements. A builder who has recently had financial conditions placed on their licence may be at risk of insolvency. Check the public register for any conditions, sanctions, or disciplinary actions.
3
Request a detailed scope of works, not just a lump-sum price
A one-line quote of "$350,000 for your renovation" tells you nothing. Insist on a fully itemised scope of works that lists each trade, materials, allowances, PC (prime cost) items, and provisional sums so you can compare quotes fairly and avoid surprise variations.
4
Confirm how they handle variations and cost overruns
Variations are the number-one source of building disputes in Australia. Ask how changes are documented and priced, whether there is a margin applied to variations, and ensure the contract requires written approval before any variation work commences.
5
Check their licence class matches the scale of your project
Builder licences are tiered by project scale — for example, QBCC offers Low Rise (up to 2 storeys), Medium Rise (up to 3 storeys), and Open (unrestricted). A builder licensed only for Low Rise cannot legally construct a three-storey townhouse. Verify the licence class on the relevant state register.

Red Flags When Hiring a Builder

No Home Warranty Insurance certificate for work over the threshold:Builders are legally required to provide Home Warranty Insurance before starting residential work above the state threshold. If a builder says insurance "isn't needed" or asks you to split the contract to stay under the threshold, walk away — this is a serious red flag and may indicate they cannot obtain insurance.
Demands large upfront deposits beyond the legal limit:Most states cap the deposit a builder can request — for example, 5% in Victoria and 10% in NSW for contracts over $20,000. A builder requesting 30–50% upfront may have cash flow problems and could be using your deposit to fund other projects.
Reluctant to put the scope of works in writing:For residential building work above the relevant threshold, a written contract is a legal requirement in every state. A builder who resists putting the full scope, timeline, and payment schedule in writing is exposing you to variations, disputes, and limited legal recourse.
Multiple current disciplinary actions on the public register:Check the state licensing register (e.g. QBCC, NSW Fair Trading, VBA) for any directions to rectify, licence conditions, or complaint history. One resolved complaint is normal; multiple open actions suggest systemic quality or conduct issues.

Typical Builder Costs in Western Australia

Hourly Rate

$75 – $130

Callout Fee

$85 – $160

Common Builder Jobs & Estimated Costs

Job	Estimated Cost
Deck construction (20-30sqm)	$5,400 – $16,200
Bathroom renovation	$16,200 – $37,800
Kitchen renovation	$21,600 – $54,000
Granny flat construction	$86,400 – $162,000
Carport or pergola build	$5,400 – $12,960

Builder Complaints & Disputes in Western Australia

Building and Energy (DMIRS)

1300 489 099 Website

How to Lodge a Complaint

1Write to the builder/tradesperson outlining the issues and requesting rectification within 14–28 days
2If unresolved, lodge a complaint with Building and Energy online or by phone
3Building and Energy will assess the complaint and may conduct an investigation or inspection
4For building disputes, a building inspector may prepare a report on the defective work
5If the complaint involves a breach of regulations, Building and Energy can take disciplinary or compliance action

Related Directories

Frequently Asked Questions

What is the difference between a builder and a building contractor?

In most states, the terms are interchangeable for licensing purposes. A "builder" typically refers to someone who constructs or renovates buildings, while a "building contractor" holds the licence that allows them to contract for building work and engage subcontractors. Some states distinguish between a general contractor (whole-of-build) and a specialist or trade contractor (single trade like carpentry or tiling).

What does Home Warranty Insurance actually cover?

Home Warranty Insurance (known as Home Building Compensation in NSW) covers homeowners if the builder cannot complete the work or fix defects due to death, disappearance, or insolvency. It typically covers structural defects for 6 years and non-structural defects for 2 years after completion. It does not cover disputes about quality while the builder is still trading — that is handled through the building tribunal or commission.

How much does it cost to build a house per square metre in Australia?

As a rough guide, expect $1,800–$2,500 per square metre for a standard project home, $2,500–$3,500 for a custom design, and $3,500 or more for architecturally designed or high-specification builds. Costs vary significantly by state, site conditions, finishes, and market demand. Always get at least three detailed quotes for your specific plans and site.

What licence types are available for builders in Western Australia?

Western Australia offers 3 licence types for builders: Building Contractor Registration — Unrestricted, Building Contractor Registration — Group 1 (Houses), Building Contractor Registration — Group 2 (Alterations). Each licence class authorises different scopes of work, so check that your builder's licence covers the specific work you need.

How much does a builder licence cost in Western Australia?

The application fee for a builder licence in Western Australia is $785 for building contractor registration. Renewal costs $496 triennially and must be renewed every 3 years.

What builder work can I do without a licence in Western Australia?

In Western Australia, some minor builder tasks are exempt from licensing requirements: Work valued under $7,500 (non-structural, non-specialist); Owner-builder work with an Owner Builder Approval (for work over $20,000); Minor maintenance, repairs, and painting. Any work beyond these exemptions must be done by a licensed builder.

How many licensed builders are there in Western Australia?

As of February 2026, there are 20,449 licensed builders registered with Department of Mines, Industry Regulation and Safety in Western Australia. This includes all licence classes: Building Practitioner - Current, Building Contractor - Current, Building Contractor - Expired, Building Practitioner - Expired.

How do I verify a builder's licence in Western Australia?

You can verify any Western Australia builder's licence using TradieVerify's free search tool or directly through Department of Mines, Industry Regulation and Safety at https://www.demirs.wa.gov.au. Enter the builder's name or licence number to confirm their registration status, licence class, and any disciplinary history.