Fun Facts about building in Ontario and the Ontario Building Code.
You may have heard that for a building less than 100 square feet, a permit is not required. This is not actually entirely true. First, it is 10 square meters which is actually 107.6 square feet (great news for some!). Second, if the building contains plumbing, it requires a building permit regardless of the size (not so great news for others).
You may have also heard that the rule now is 160 square feet, but this is only if the building is used for storage, definitely not living space.
It is all in the definition of a building found in the Building Code Act. If you are required to get a permit, then you will need working drawings by an Architect, an Engineer or a BCIN Designer.