A home extension is exciting. It means more space, more comfort, and a property that works harder for your family. But the process of choosing who builds it can feel overwhelming, especially when you are comparing quotes, reading through contracts, and trying to work out who you can genuinely trust. The good news is that a handful of straightforward checks will tell you almost everything you need to know about a builder before you sign a single document. Taking the time to do these checks properly is not about being difficult or suspicious. It is simply smart planning.

The first thing to verify is a builder's licence. In Australia, builders who carry out residential construction work above a certain value must hold a valid licence issued by the relevant state authority. In New South Wales, for example, this is managed through NSW Fair Trading, while Queensland builders are registered with the Queensland Building and Construction Commission. These registers are publicly searchable, so you can confirm a licence number in a matter of minutes. Never rely on a business card or a verbal assurance. Look the licence up yourself, check that it is current, and confirm that the licence category covers the type of work you need done. This one step alone filters out a significant number of risky operators.

Once you have confirmed the licence, turn your attention to insurance. A reputable builder will carry public liability insurance and, for residential work, home warranty insurance where it is required in your state. Public liability insurance protects you if someone is injured or property is damaged during the build. Home warranty insurance provides a safety net if the builder cannot complete the work or remedy defects. Ask to see certificates of currency for both policies, and check the expiry dates carefully. If a builder hesitates to provide this documentation or cannot produce it promptly, treat that as a clear warning sign and keep looking.

Portfolio review is the next step, and it is one that many homeowners rush through when they should slow down. Ask to see completed projects that are similar in scale and style to what you have in mind. Better still, ask whether you can speak with previous clients directly. A builder who is proud of their work will welcome this request. When you look through photos or visit a completed site, pay attention to the quality of finishes, the neatness of joins and edges, and how well the extension integrates with the existing structure. These details reveal craftsmanship far more honestly than a polished website ever can.

When you move to the contract stage, read every page carefully and do not feel pressured to sign quickly. A well-written contract should clearly set out the scope of work, the materials to be used, the payment schedule, the timeline, and the process for handling variations. Be cautious of contracts that are vague about scope, that require very large upfront deposits, or that include clauses making it difficult for you to raise concerns or request changes. In Australia, consumer protection laws provide homeowners with certain rights in residential building contracts, so it is worth familiarising yourself with the rules in your state before you reach this stage. If anything in the contract is unclear, ask for a written explanation before you proceed.

Communication style is also a telling indicator of how a builder will behave throughout the project. From your very first enquiry, notice how quickly and clearly they respond. Do they listen carefully to what you want, or do they push their preferred approach from the start? Do they explain things in plain language, or do they use jargon that leaves you more confused? A builder who communicates well in the early stages is far more likely to keep you informed, handle problems constructively, and deliver a finished result you are genuinely happy with. Trust your instincts here. If something feels off in the way they communicate before the contract is signed, it will almost certainly feel worse once the work is underway.

Once you have confirmed the licence, turn your attention to insurance. A reputable builder will carry public liability insurance and, for residential work, home warranty insurance where it is required in your state. Public liability insurance protects you if someone is injured or property is damaged during the build. Home warranty insurance provides a safety net if the builder cannot complete the work or remedy defects. Ask to see certificates of currency for both policies, and check the expiry dates carefully. If a builder hesitates to provide this documentation or cannot produce it promptly, treat that as a clear warning sign and keep looking.

Portfolio review is the next step, and it is one that many homeowners rush through when they should slow down. Ask to see completed projects that are similar in scale and style to what you have in mind. Better still, ask whether you can speak with previous clients directly. A builder who is proud of their work will welcome this request. When you look through photos or visit a completed site, pay attention to the quality of finishes, the neatness of joins and edges, and how well the extension integrates with the existing structure. These details reveal craftsmanship far more honestly than a polished website ever can.

When you move to the contract stage, read every page carefully and do not feel pressured to sign quickly. A well-written contract should clearly set out the scope of work, the materials to be used, the payment schedule, the timeline, and the process for handling variations. Be cautious of contracts that are vague about scope, that require very large upfront deposits, or that include clauses making it difficult for you to raise concerns or request changes. In Australia, consumer protection laws provide homeowners with certain rights in residential building contracts, so it is worth familiarising yourself with the rules in your state before you reach this stage. If anything in the contract is unclear, ask for a written explanation before you proceed.

Communication style is also a telling indicator of how a builder will behave throughout the project. From your very first enquiry, notice how quickly and clearly they respond. Do they listen carefully to what you want, or do they push their preferred approach from the start? Do they explain things in plain language, or do they use jargon that leaves you more confused? A builder who communicates well in the early stages is far more likely to keep you informed, handle problems constructively, and deliver a finished result you are genuinely happy with. Trust your instincts here. If something feels off in the way they communicate before the contract is signed, it will almost certainly feel worse once the work is underway.