What is Universal Design?

Seven Principles of Universal Design

1. Equitable Use: The design is useful and marketable to any group of users.
2. Flexibility in Use: The design accommodates a wide range of individual preferences and abilities.
3. Simple and Intuitive Use: Use of the design is easy to understand.
4. Perceptible Information: The design communicates necessary information effectively to the user.
5. Tolerance for Error: The design minimizes hazards and the adverse consequences of accidental or unintentional actions.
6. Low Physical Effort: The design can be used efficiently and comfortably.
7. Size and Space for Approach and Use: Appropriate size and space is provided for approach and use.

Source and for more information on Universal Design: 

http://www.makoa.org/accessable-design.htm