Table 2: Additional theories of design.

Design theoryDefinitionExample

Accessible design [46]Provides separate design features for user groups with disabilities
Usually permanent and noticeable
Fulfills code requirements for use by individuals with disabilities
Provide the minimum level of accessibility required by the local building code.
This can vary by region (e.g., province or state), and with different building types within the same region.
For example, Ontario Building Code requires power door operators (e.g., push button, automatic sensor, etc.) on entrances to hotels, but not on entrances to stand-alone office spaces of less than 300 m2 [47].

Adaptable design [46]Provides design features that are usable by groups with disabilities, however remain concealed or omitted until needed
Features are either adjustable or easily and quickly added or removed in order to “adapt” the environment for specific individuals
An electronic push button is provided to open the door, but the use of the push button is optional (i.e., door will open manually).

Transgenerational design [48]Develops products and environments that are compatible with the natural physical and sensory declines experienced during the aging processProvide a power assist door, which augments the force applied by the user to fully open the door [49].