The phrase "same roof" means that two or more people live in the same house or building. It implies that they share a living space and are physically located in the same place. Full definition
Do I have to include my spouse's income for means testing if I file an individual bankruptcy while my spouse and I are living separate and apart under same roof? (bankruptcydivorceblawg.com)
Pekan Private Suite is a separate bedroom under same roof of main house, but with its own entrance and kitchenette. (travelground.com)