I add that the the provision of social housing is a field subject to a lot of regulation. You can't just waltz in and set up your own housing association or charity without dealing with the regulatory issues.
You could consult Anthony Gold, a leading law firm in this field, or consult one of the direct public access housing law barristers at 4-5 Gray's Inn Square. Their expertise has a price. As the saying goes: you can have a cheap lawyer, or a good lawyer. In the law, you get what you pay for, and free legal advice is often worth exactly what you paid for it.