Tigs,
Regardless of whether a number of residents are already running businesses from their homes on Grays Lane, the big point is that the SSAFA home would not be a business. Indeed, they should be staying as guests of SSAFA and invited to make a donation towards running costs. My folks (both retired) are short of cash and so if my kids go and stay with them, we hand across seom cash to cover their food and laundry costs so that my parents aren't out of pocket. That does not make them a boarding house...