We recommend that you get expert help when preparing DAs for more complex developments. Whilst most architects are able to handle most residential developments, larger or more complex developments may require design input from a wide range of experts including:
The best way to find the right expert is by personal referral and through their professional associations or accreditation bodies (we have given links above to the associations/bodies best known to us but you need to do you own background checks before employing anyone).
You should visit the Building Professionals Board when selecting an Accredited Certifier or Principal Certifying Authority for the building (Construction Certificate) stage and beyond. More information about Construction Certificates and Principal Certifying Authority Services.
The other good way to select an expert is by their demonstrated performance in Land and Environment Court cases as advocate experts or Court Appointed Experts. The Court's judgements often pass comment on whether or not the Court accepted the evidence of particular experts and what weight the Court gave to such evidence. You can search the judgements online.
We cannot recommend any particular individual.