I don't think it's stupid. I've been thinking about this a lot of late. I live in a city where there seem to be a lot of homeless people, and with the weather as it is, I find it hard to walk past them each morning.
However, a VAST amount of office space in this city, sits empty. Office space where the landlord is liable for 100% business rates. Much of this office space has all the facilities you would find at work; toilets, kitchen and so forth.
Charities, receive 80% rate relief and a further discretionary 20% rate relief can be applied dependent on the council. Therefore saving the landlord thousands of pounds if the space is occupied for a charity. That charity could be a homeless charity, they could even ask for 50% of the rates from the landlord with part being a donation, part being the business rates they are liable for, saving the landlord 50% and generating money for charitable purposes within that space.
I know there are a million and one questions linked to this and it isn't straightforward; how it is managed or 'policed', how the spaces are maintained, what it does to a neighbourhood or a potential rental, but that said we are (through my employer) regularly asked to notify the police of hotspots of homeless people as it's perceived somewhere to be a blight on society and actually I find it a greater waste of public money and services to move people on who have no where to move on to, for the sake of public perception, rather than find them a solution which may see them integrate back into society which is where they want them to be.