I know the time scale is "how long is a piece of string", as much as I'd love to get this tomorrow.
Its mostly curiosity about why these jobs are showing up where they are and what the purpose might be. I hardly leave the house due to a random sleep pattern and anxiety, so while it might seem unhealthy to be dwelling on the details, for me its not. If my health problems hadn't been a major barrier (funnily enough people don't like employees who run to their own timetable), I'd be working in IT, so trying to work out of the details of this sort of thing is very much what I'm interesting in.
Like I said, the other side of the road from me is ductless, at least running up to each maisonette. So it should be pretty obvious once anything interesting is happening as presumably they would have to run new duct up to each building? I'm certainly going to notice that from the CCTV on the front door.