Renovations by Owners to the Common Property of the Plan can only be permitted under the provisions of a Special By-Law that’s been resolved by >75% of Owners present in person or by proxy at a General Meeting of the Owners Corporation (O/C) voting in favour of its Registration.
Whilst it’s a good idea for Owners to consult with the Executive Committee (EC) to as you say “iron out any concerns … and facilitate O/C approval”, the O/C cannot approve any renovations (alterations/additions) to the Common Property unless that Special By-Law (above) is in place and properly Registered, and even then, only in accordance with the provisions of that Special By-Law – which could include the requirement for Engineers to be commissioned by the EC if that’s what was agreed to at the General Meeting.
So….it’s fine for your EC Member to introduce a Special By-Law to all Owners at a General Meeting, where if a quorum is present it’s then up to the majority (>75%) to agree to the proposed provisions or to reject those.