If disability is determined to be the need for solutions that are a modification of the “norm,” then every person experiences disability in their lifetime. Disability can come in the form of physical, developmental, intellectual, sensory, weight, height, and age limitations (in addition to countless others not mentioned). The fact that all adults were once children, places them in the company of every other person on the planet who has lived with disability. Every person has or will become a member of this group. Typical design addresses the needs of able-bodied adults (in stature and mental capacity), often missing the opportunity to provide design that serves the segment of the world currently experiencing a disability. The good news is that we have tools to design a world that addresses the needs of this group. These tools are captured in the concept of Universal Design.
The 7 Principles of Universal Design were developed in 1997 by a working group of architects, product designers, engineers, and environmental design researchers, led by the late Ronald Mace. The purpose of the Principles is to guide the design of environments, products, and communications. According to the Center for Universal Design in NCSU, the Principles "may be applied to evaluate existing designs, guide the design process and educate both designers and consumers about the characteristics of more usable products and environments." The 7 Principles are as follows:
Principle 1: Equitable Use
- Provide the same means of use for all users: identical whenever possible; equivalent when not.
- Avoid segregating or stigmatizing any users.
- Provisions for privacy, security, and safety should be equally available to all users.
- Make the design appealing to all users.
Principle 2: Flexibility in Use
- Provide choice in methods of use.
- Accommodate right- or left-handed access and use.
- Facilitate the user's accuracy and precision.
- Provide adaptability to the user's pace.
Principle 3: Simple and Intuitive Use
- Eliminate unnecessary complexity.
- Be consistent with user expectations and intuition.
- Accommodate a wide range of literacy and language skills.
- Arrange information consistent with its importance.
- Provide effective prompting and feedback during and after task completion.
Principle 4: Perceptible Information
- Use different modes (pictorial, verbal, tactile) for redundant presentation of essential information.
- Provide adequate contrast between essential information and its surroundings.
- Maximize "legibility" of essential information.
- Differentiate elements in ways that can be described (i.e., make it easy to give instructions or directions).
- Provide compatibility with a variety of techniques or devices used by people with sensory limitations.
Principle 5: Tolerance of Error
- Arrange elements to minimize hazards and errors: most used elements, most accessible; hazardous elements eliminated, isolated, or shielded.
- Provide warnings of hazards and errors.
- Provide fail safe features.
- Discourage unconscious action in tasks that require vigilance.
Principle 6: Low Physical Effort
- Allow user to maintain a neutral body position.
- Use reasonable operating forces.
- Minimize repetitive actions.
- Minimize sustained physical effort.
Principle 7: Size and Space for Approach and Use
- Provide a clear line of sight to important elements for any seated or standing user.
- Make reach to all components comfortable for any seated or standing user.
- Accommodate variations in hand and grip size.
- Provide adequate space for the use of assistive devices or personal assistance.
While the Americans with Disabilities Act provides minimum guidelines that have been incorporated into the design requirements for public buildings, there is often far more that architects and designers can do to create spaces that serve everyone, regardless of ability.