Form 15 and Form 16 explained: who signs what on a Queensland build

The difference in one line

A Form 15 is a compliance certificate for design or specification, generally provided by an engineer or other competent person. A Form 16 is an inspection certificate for an aspect of work, generally provided by a licensed contractor confirming that specific work has been carried out and complies with the relevant requirements. In short, a Form 15 certifies a design, and a Form 16 certifies that installed work matches what was required.

Form 15: certifying the design

A Form 15 is used when an element of a building's design needs to be certified by someone with specific competence in that area, most commonly a structural, civil or hydraulic engineer. Rather than your building certifier independently re-engineering every structural element on a project, the engineer who designed it certifies, via a Form 15, that the design complies with the relevant standards and the NCC.

Your certifier relies on these Form 15 certificates as part of the overall building approval and final certification process. Common examples include structural engineering for footings, slabs, and structural framing elements, and specialist design for retaining walls or other engineered structures.

Form 16: certifying the work was done properly

A Form 16 works differently. It is an inspection certificate confirming that a specific aspect of work, once installed or constructed, has been inspected by a licensed contractor and complies with the applicable requirements. This is common for elements such as certain plumbing and drainage work, termite management systems, and other trade-specific work where the licensed contractor carrying out the work is best placed to confirm it has been done correctly.

Where your certifier is not personally inspecting every element of a build, Form 16 certificates from the relevant licensed contractors fill that gap, giving the certifier confidence that work has been checked by someone appropriately licensed and qualified.

Why your certifier needs both

Your certifier's job is to build a complete compliance picture of the whole project, from design through to completed construction. Form 15 certificates confirm the design was sound before it was built. Form 16 certificates confirm the installed work matches what was required. Neither one on its own tells the whole story, which is why both tend to be requested at different points across a project.

Without the relevant Form 15 or Form 16 certificates in hand, your certifier generally cannot progress a stage inspection or issue the final certificate for elements that depend on them. This is one of the more common reasons a final inspection gets delayed near the end of a project, so it pays to track which certificates are outstanding well before you expect to need the Form 21 or Form 11.

Who is responsible for getting them

Generally, your builder coordinates the collection of Form 15 and Form 16 certificates from the relevant engineers and contractors as work progresses, and passes them on to the certifier. As the homeowner or project owner, it is worth asking your builder early in the project which Form 15 and Form 16 certificates will be needed, and checking in on progress as key stages such as slab and frame approach, rather than discovering a gap at final inspection.

Common gaps that cause delays

A few situations come up repeatedly:

Raising expectations about these forms with your builder at the start of the project, rather than at handover, generally avoids all of them.

Key takeaways

If you are partway through a build and want clarity on which Form 15 and Form 16 certificates your certifier still needs, our building approvals for new homes and mandatory building inspections pages cover how the process fits together. Call our Woolloongabba office on (07) 3112 7689, or send us your project details through our get a free quote page.