What about reversing the order of things? The OC could vote to give approval conditional on receiving the appropriate Development Approval, engineer’s report, maintenance or repair requirements, and so on.
That is how our OC does it. In our case the Executive Committee (EC) has authority to approve unit alterations on behalf of the Owners Corporation (OC). The EC is constrained in what it can approve by various resolutions of the OC directing the EC to only approve after consulting the immediately surrounding neighbours or anyone else who might be affected and within various guidelines on architectural style, colour and materials.
Sometimes we go back and forth a few times informally with an owner before they present a proposal that the EC is likely to approve or able to approve. Proposals are approved subject to compliance with any local government requirements such as DA, which covers engineering, safety etc. Approval is also made subject to restoring any damage to common property that might occur during construction.