Universal Design is a great concept that I heartily encourage. In fact I have written 4 books and 4 eBooks about this subject, and we just finished the two-day course on Universal Design/Build.
Universal Design as a concept incorporates easily accessible elements in a home for any occupant of that home regarless of their age, ability, or size. It is not, strictly speaking, Aging-in-Place although Universal design is a great beginning point for that, and it facilitates it quite well.
Aging-in-Place as a concept addresses more specific issues dealing with mobility, sensory, and cognitive concerns that are a part of getting older. However, Universal Design accommodates much of what someone normally aging will appreciate - as well as what younger people in the home and guests can enjoy also.