Thank you for the information. The more you include as a "must-have" (breakfast in the sunshine, etc.), the less likely it is to get a good floor plan. I understand everyone, the reasons mentioned and also the concerns about the mother aging, the children, the need for an office, etc. Everything has its justification but of course brings cost/planning problems. We also lived with our parents in the house for many years, and they themselves only wanted a small apartment in the basement. We did not want that, since we received equity from them, so we built them a (perhaps too) large apartment on the upper floor with a roof terrace and a great view. There are too many things and eventualities that need to be considered, and in the end, things turn out differently with grandma, the children, or in one's own life. When I look at the past and current environment, I know hardly anyone who, in old age, would no longer be able to manage at least a few steps up/down, even if it’s sometimes slow, which is not a problem. We are currently driving to the assisted living of an elderly lady, 89, who even refuses the elevator there. In my experience, someone who can no longer climb any stairs at all usually cannot leave the house alone anymore; that was the case with my father, whom we then brought downstairs twice a week, and he gladly lived on the upper floor until the end. Usually, quite different issues come to light that really cause problems, such as orientation problems, dementia, and others. What I want to say is that in your situation, I would actually consider relocating the granny flat to the upper floor and already provide for connections for a stairlift for safety. From above she certainly has a good view, and you could plan more freely down below. A good (interior/architect) could surely design something like that for you and best represent the diverse needs (family, grandma, possibly soon moving-out children (then at 26?). One thing like "breakfast in the sunshine,"