Large room for a lodger, 5mins from Central Line

tha Gild
Medway Estate
The situation is my Mum stays only downstairs in one room as she's bed bound (Parkinson's, hip breaks) so 4 times a day a carer lets themself in and changes her if needed, gives meds and food, but they never go upstairs and it's for half an hour to an hour each visit (last visit is 8pm). Theres a bathroom upstairs with a bath and shower, a storage room and a smaller box room where my mate Chris is lodging. He's very neat and organised, hardly ever hear him when I'm staying with Mum (my wife and kids are in Japan so I go back and forth). As it's lodging to essentially pay for Mum's care, bills etc I was thinking £800 a month including bills. There's a dining room downstairs with a tumble dryer, washing machine in the kitchen (Chris doesn't cook so whoever moved in would have it to themselves most of the time). Garden is large but I need to work on it, it was left to the elements, but the house is right next to a big park which hardly anyone uses which is nice.

Council tax band I'm unsure as it's for a lodger. I'll update once I find out!