The existing door onto the courtyard is Common Property, and the new Owner needs to obtain the Owners Corporation’s (O/C) consent prior to making any changes or alterations to that Property. That consent may be given in the form of a letter signed by the Executive Committee (E/C) Secretary on behalf of the O/C, and should incorporate appropriate Conditions relating to matters such as work times (noise), the use of tradespeople (licenses/insurance), and who is responsible for ongoing maintenance and repairs to the new stacking door (the lot owner in lieu of the O/C).
Why the new By-Law – called a Special By-Law (SBL) as it’s made subsequently and is additional to the standard By-Laws prescribed in S1 to NSW Strata Schemes Management Act & in the Regulation?
Well, your O /C may be expecting other lot owners to seek its consent for this same change/alteration to common property, so as an alternative to it receiving multiple requests for and making multiple consents to the same scope of works, your E/C’s decided to put a SBL covering those works to a General Meeting of Owners for consideration.
So the Special By-Law replaces (as opposed to negates) the consent of the Executive Committee, and provided all lot owners in future follow the provisions of that SBL absolutely, they don’t need to seek the O/C’s consent .
A Special By-Law requires a Special Resolution of Owners at a General Meeting – that is where no more than 25% of Owners present at that Meeting (personally and by proxy) can be against the Motion (or a min 75% must be in favour), and it’s usual for the Owner who’s requiring/benefiting from the Special By-Law to pay for its expert drafting (i.e. by a Strata Specialist / Lawyer) and Registration with NSW Land & Property Information (the old Land Titles Office).
Re the air-conditioning (A/C) – that too would be covered under a (different) Special By-Law, and if you’re saying that works have been done without the respective lot owners paying for a SBL, that’s the idea! Once the cost of drafting/registering a SBL’s been paid for by an owner or by the O/C, then all future works of the same types (i.e. A/C) can be completed under the provisions of the SBL
I hope this clarifies matters for you.