That depends on a number of factors.
- Will any of your neighbours report your construction activity?
- Will a relative or friend report what you are doing?
- Will you be renting the constructed space to a third party?
- Will you have a flood or some other event that causes you to make an insurance claim?
If the answer is yes to any of these questions, you could face some very serious consequences. Things have changed over the last few years, and one of those changes is the obligation of municipalities to enforce the Ontario Building Code as mandated by the Ontario Building Code Act S.O. 1992 ( https://www.ontario.ca/laws/statute/92b23 )
Here is a story about a landlord that did not follow the Ontario Building Code and municipal regulations regarding rental suites.