It would probably help a lot if you could stop thinking about “them and you” as if they were rivals or some unseen hand. The Executive Committee actually represent the combined wishes of every owner in the building including you. The by-laws are only there because owners have collectively agreed on them and the reason they have agreed on these fairly restrictive ones is so that the apartment block doesn’t turn into a 24/7 building site (because renovations spread like a virus).
Seriously, one of the most prestigious blocks in this city was turned into a virtual building site with not restrictions on noise, mess or disruprion for about two years because a greedy real estate agent got himself elected on to the committee, wiped out all restrictions on renovations and made a fortune encouraging owners to amalgamate. Without the by-laws in place, the other residents who had spent a fortune on the place could do nothing.
So take a step back and ask yourself how unreasonable is it for your neighbours to want some peace and quiet at weekends, early in the morning and later at night (as you will too when your renos are done).
As to what rights they have – they aren’t contradictory to Fair Trading rules (whatever they are)- they are on top of them. If you breach the by-laws, not only will you be subject to Notices to Comply, orders to stop work and possible fines, you will suddenly find that your builders’ access to parking and lifts has disappeared and your EC could also be raising objections at local council.
The by-laws may well be unreasonable but the time to challenge them isn’t a couple of weeks before you want to do work out of hours, it’s at an AGM. The rules are there for owners and agreed by owners. And if the majority of owners agree with you, then they’ll be changed. If they don’t that you have to livve with that.
Seriously, the best plan for all concerned – and for your future harmonious living in this community – is to find ways of getting this done with minimal disruption to your neighbours, rather than asking how someone can breach the by-laws and get away with it.