As to the punctilious detail on what is also not allowed – all the stuff about drilling holes and visibility etc etc – I wonder if this goes back to what is now known as the Jo Cooper case which overturned a blanket ban on pets in her apartment block.
What’s the connection? It was the blanket nature of the ban that fell foul of the law, not the idea that any specific dog might be refused entry. Thus a blanket ban on aircon is also expressed in details that would render it impossible to install a system.