Lifemark in New Zealand has several good case studies of universally designed homes. Some are modest homes and some are more upmarket.
The latest edition of their newsletter features a spacious home with great views. The owners, Max and Tricia have an interesting story to tell. Max is a mechanical engineer who taught environmental and spatial home design to architecture students. He knew about accessibility but not heard of universal design. Turns out that one of Max’s students in 1995 became the designer of their new home. The story of Max and Tricia has some nice detail and pictures in the article.
Not everyone has money to spend on a “grand design”, but it doesn’t have to be grand to be universally designed and suitable for everyone. Lifemark has a gallery of homes designed with universal design principles on their website. There’s also some examples of retrofits.