A roommate arrangement also addresses isolation and practical help around the house, which matters for a senior aging in place, though it does not solve deferred maintenance or a home that has genuinely become too much house to manage.
Legally, a roommate is a tenant under the Residential Tenancies Act, 2006 the moment rent changes hands, which means proper notice rules, deposit handling and the same landlord obligations apply even to an informal-sounding arrangement between friends or family.
A senior weighing a roommate against selling should know the home's real value first so the comparison is honest. Get your hand-reviewed valuation from Joel Dyck.