Posting here for traffic. We're thinking of proposing that my mum move in with us. She's in her early 80's and starting to struggle but lives 200 miles away. I have 2 siblings that live locally to her but they can't/won't help out much. We already have a converted garage that is a bedroom and ensuite, but would want to do a small extension to give her her own living area with kitchenette. My mum currently owns her own house outright in an expensive city. The extension would improve our property so we would contribute, but is is fair that she also contributes? Do I suggest that this is deducted from my portion of inheritance? It would be great to hear if anyone has done similar and how they worked it out.