What is it that needs to be accommodated?

In each province’s human rights legislation (and in the federal human rights law, for federally-regulated employees) there is a list of what are known as ‘protected grounds’; criteria that employees and applicants for employment cannot be discriminated against based upon. The list varies between provinces, but generally includes race, ethnic origin, citizenship, sexual orientation, gender identity/gender expression, age, pregnancy, marital status, family status, and disability – just to name a few. 

Not all of these grounds spill over into the field of accommodation – it would be unlikely to need to accommodate an employee based on their race, for example. Accommodation usually tends to center around grounds such as family status (care issues), disability (physical accommodations), pregnancy, and occasionally some others as well.