I think what you also have to look at is the effects on the people living in the flats. If it was simply someone sleeping there then I don't think that would be much of a problem but what I remember was being 16, being given a scatter flat, being pregnant, alone and afraid because the homeless people that slept in the close and alleyway beside the flats were drug users and would accost me for money when I was passing to the point where I was terrified going to the bin at night.
I would go to the shop in the morning and have to step over used needles and bags and all sorts of paraphernalia, the police would be round regularly, there would be banging at the door because they were so out their face they got the wrong flat number, fires would be set and all I could think was I didn't want my baby there.
Thankfully I got a flat before he was born but it opened my eyes and I know not all homeless people behave and live like this but it was terrifying and it shouldn't be up to the residents of these properties to have to deal with the consequences of these people having nowhere to go.