Principle 1: Equitable Use
Making sure that usability of the design is equal for all users, including those with a mental or physical disability, the elderly and children through either an identical or similar process.
This also applies for the aesthetics and safety functions – everyone should be able to enjoy or use the finished outcome equally.
For example: For identical use, making entranceways at ground level means wheelchair users can still access the building. An example of similar use is installation of a platform lift near a staircase, meaning people of all abilities can access all floors.
Principle 2: Flexibility in Use
The design should incorporate flexibility for use in differing ways – whether this be preference or requirement based on ability or mobility.
Speed is common; making it possible to slow down or speed up based on the users skill or mobility. Another common example is to design for both left and right handed people.
For example: a fold down shower seat allows less mobile users to sit, as well as the elderly, but by folding away the shower can still be used by the ambulant or those who prefer not to.
Principle 3: Simple and Intuitive Use
Regardless of ability, age, language, mobility (and so on) the user should be able to understand the design and be able to use it easily. The easier it is to use, the more people will be able to use it.
Reducing complex information is key, making it unambiguous. Take into account a range of language and reading abilities, and ensure that there are pointers, instructions or feedbacks if required.
For example: Ikea have designed all of their shops to have a simple route guiding customers through the shop. This is clearly marked with simple arrows on the floor, easy for anyone to understand.
Principle 4: Perceptible Information
The design should provide any required information to every user. This should apply to all situations, including the blind, or a noisy environment. Use of pictures, verbal and tactile information provide information clearly –but where text is used, remember to keep it clearly readable using a simple font.
The most important information should be the most prominent, using a ‘visual hierarchy’ concept.
For example: All Gartec lifts can have buttons with the floor number clearly written, tactile braille buttons and voice annunciation at floors, making it clear and simple for all users.