It is not up to the OC to engage someone to determine if new membranes comply, or if any other works comply. That would place the OC in a very difficult position.
Standard drafting of approval given for renovations and any related by-laws will include wording to the effect that the lot owner will ensure that the work will be carried out in a professional manner by licensed tradesmen, that the work will meet any applicable standards, and the owner is responsible for any maintenance of that work in the future.
If the OC inspects work carried out by an owner then it could be claimed that it is responsible for it.