As in most states, a by-law can only be created or altered in WA by a special resolution at a properly notified and convened general meeting.
To achieve a special resolution in WA strata schemes, it has to be agreed on at a general meeting by no fewer than 50 percent of the owners numerically who must also represent a total of no less than 50 per cent of the unit entitlements.
Furthermore, it must not be opposed by more than 25 per cent of owners and/or owners holding 25 percent of unit entitlements.
However, owners have 28 days from the meeting to gather enough dissenting votes and send a letter to that effect to overturn the by-law.
If your committee did not hold a general meeting for all owners, then the by-law is invalid. If they did hold a properly constituted general meeting, then the above conditions apply.
Frankly, unless you have 50 percent of owners turning up at meetings in person or by proxy, I can’t see how by-laws ever get passed. And I defiinitely can’t see how they would ever be altered if they were legitimate in the first place.
You’ll find the letter of the law HERE. Good luck.