If this is a long-term home, you are designing for yourself today and for yourself decades from now.
Those people may have different needs.
Avoid unnecessary steps where possible. Zero-step entries can look completely normal when planned from the beginning.
If the house has multiple floors, consider whether someone could live entirely on the main level if necessary.
A bedroom, full bathroom, kitchen, and living space can make a huge difference later.
Wider doors, curbless showers, lever handles, reachable controls, and adequate bathroom clearances do not have to look institutional.
Good universal design is often invisible.
If you may someday need an elevator, stacked closets or a future shaft can preserve that option.
You do not need to build a nursing home.
You need to avoid building a house that becomes unusable because your knees changed.