Aha - it's in his YouTube speech - here's a screengrab. He wants the council to "DONATE" a building to the charity.
Now, it doesn't say which building, or what it's worth, or whether it would need any work doing before handing it over etc. But the point is, if that building is owned by the council, so that it could use it to raise funds for services in the area, and there is a rich celebrity demanding that it be given to charity, would that be what local tax payers would want? Or would they think, erm, YOU have a big house and lots of cash, YOU house some people in need!