Think I disagree with Kevin & junderw.
The guardian basically has a number of powers from s7 MHA 1983 aimed at ensuring a patient requiring treatment receives it. The main ones are:
Requirement to live at a specific address.
Requirement to attend treatment.
Requirement to give access to a social worker/health worker etc.
Although a guardian is, almost invariably, the L.A. this does not always have to be the case. It may be a relative etc.
I do not think that social services would be responsible for housing costs just because a person has been received into guardianship.
NB: There was talk of changing the law regarding this matter early last year & I do not know what hgappened – it may be worth investigating the current situation.