Building certifiers in Queensland do not personally check every aspect of a job. For anything outside their own expertise, the Building Act 1975 lets them rely on certificates from a competent person. Two of the Queensland Government's approved forms carry most of that weight, and builders, project managers and site owners meet them on nearly every industrial and commercial job.
Form 15: the design certificate
A Form 15 is a compliance certificate for building design or specification. The competent person certifies that the design of a particular aspect complies with the building assessment provisions, which for engineered work means the National Construction Code and the Australian Standards it references. It is issued for a defined aspect, not the whole building: a structural steel platform, a mezzanine floor, an equipment support frame, an awning, a mechanical services installation.
Timing: the Form 15 belongs with the building application, or at the latest before the certifier approves that aspect. A certifier who receives a design without one will ask for it, and nothing about that aspect proceeds until it arrives.
Form 16: the inspection certificate
A Form 16 is an inspection certificate (also used as an aspect certificate). The competent person certifies that they inspected the work, or a specified stage of it, and that it complies with the approved design and the building assessment provisions. It is what lets the certifier sign off on an aspect they did not inspect themselves.
Timing: at the agreed inspection stages during construction and at completion. A Form 16 is a statement about what the engineer saw, so it cannot honestly be issued for work that was never inspected.
Who is a competent person
The certifier decides who is competent for each aspect, based on qualifications and experience. For any aspect that involves engineering judgement, that decision is made for them by other legislation: under the Professional Engineers Act, engineering services in Queensland must be provided by a Registered Professional Engineer of Queensland in the relevant area, or under one's direct supervision. Certifiers therefore expect an RPEQ number and the relevant area of engineering on both forms. What RPEQ registration covers.
Where mechanical engineering comes in
On industrial and commercial building work, the aspects that typically need a mechanical RPEQ on a Form 15 and Form 16 include:
- Access platforms, walkways, stairs and ladders to AS 1657, including their supporting steel.
- Equipment support frames, plinths and mezzanines carrying plant, designed to AS 4100 and AS 3990.
- Lifting beams, monorails and davits to AS 1418, and the structure they hang from.
- Pressure piping within the building to AS 4041, and the supports it loads onto the structure.
Where an aspect crosses into structural, electrical or fire engineering, the certifier will want the right registration for that part. A good engineer tells you at the start which forms they can sign and which need another discipline.
What the engineer needs from you
For a Form 15: the design documents at the revision being lodged, the loads and use the design is based on, the standards and any client specification that apply, and a clear statement from the certifier of which aspect the form is for. If the design was prepared by someone else, the engineer has to review it properly before certifying it, so allow time.
For a Form 16: access to inspect at the agreed hold points, the fabrication and installation records (material certificates, weld inspection reports, bolt tensioning records), photographs of anything that will be concealed, and a list of every variation from the approved design.
Where it goes wrong
- The Form 16 requested at handover for work the engineer never inspected. If the connections are now behind cladding or under concrete, there may be no honest way to issue it, and the certifier will not accept one issued blind.
- Site changes not covered by the Form 15. A moved column, a heavier machine, a substituted section. The design certificate no longer matches what was built, so an amended design and certificate are needed before the Form 16 can be issued.
- Forms with the wrong scope. A certificate that names the whole building when the engineer only designed the platform, or vice versa. Scope on the form should match the aspect the certifier asked for, word for word.
- Lapsed registration. RPEQ registration renews annually. A form signed by an engineer whose registration has lapsed is worthless, and certifiers do check the register.
The sequence that works
- Engage the engineer at design, and agree which aspects they will certify.
- Lodge the Form 15 with the building application.
- Agree hold points with the builder before fabrication starts.
- Call the engineer to inspect at each hold point, and whenever something changes on site.
- Receive the Form 16 at completion, with the as-built drawings, and hand both to the certifier.
Form 15 and Form 16 are approved forms under the Building Act and are updated from time to time. Use the current version from the Queensland Government's building forms page, and check that the version the certifier expects is the one being signed.