The BC government Ministry of Housing has produced a detailed guide on How to Add and Manage a Secondary Suite or Accessory Dwelling Unit in British Columbia - https://www2.gov.bc.ca/assets/gov/housing-and-tenancy/building-or-renovating/secondary-suites/home-suite-home-2023-sept-6.pdf
I am impressed how the BC government is stepping up to increasing housing - good housing, well managed housing.