Homegirls – firstly, in NSW all residents (i.e. owners and tenants) are required to comply with the Plan’s By-Laws, and in order for those to be legally enforceable in general terms they need to be either the “Model By-Laws” provided in the Strata Schemes Management Act for Plan’s registered after 1996, or in the Regulation for Plan’s registered after 2010, or to have been properly adopted at a General Meeting of the Owners Corporation from either of the above Schedules, or as “Special By-Laws” specifically for the Plan and be Registered on its Strata Title.
Obviously, there is no relevant provisions in the “Model By-Laws” about leaving gates open or otherwise, but I suspect from your post that something’s been mentioned about an open gate detracting from the appearance of the building; right?
There are Model By-Laws that relate “the appearance of the lot” but they’re not applicable to the circumstance that you describe, but even if they were, there’s a specific Form that the Executive Committee needs to provide residents with after it has met to consider whether or not a breach of a By-Law has occurred.
What to do?
Well… you could take Peter’s advice (post #2), or just ignore the missives which after all have no standing unless they’ve been decided upon by the Executive Committee as a whole and have been issued in the form required (as a Notice-to-Comply with a relevant By-Law), or maybe in this instance just close the gate.