in NSW my understanding is that, apart from the story being a probable breach of ‘appearance in keeping’ bylaws, common property items like original windows are generally repaired and maintained using common funds – but if the owner decides to renovate or replace with new/different then that incurs a change of use and thereafter the owner tends to be responsible for any repairs to it.
Our strata was asked to pay bills for $20K to stop a unit skylight leaking – but no other units had skylights. After intensive research we found the skylight was not original and had been added by a subsequent occupant. The current owner swore it wasn’t them, but wanted us to repair it. We ended up offering them two choices – either remove it to restore the roof to original (no skylight) condition (which would have cost thousands) or sign an exclusive use bylaw accepting responsibility to maintain it in future. Not wanting to pay any money now, they finally agreed to the bylaw.
Then today – undergoing renovations after poor tenants for the last four years, we get a claim from this unit for a leaking pipe. Hmm – I’m interested to see if that might come from anywhere near the skylight …