Decks, Porches and Balconies

Decks, porches and balconies are considered structures in the building code and when over 600 mm (24 in.) above ground, must be supported by frost-resistant foundations, be laterally braced, be designed to accommodate the weight of people and snow, and have stairs and railings that meet code requirements. If planning to build a deck, porch or balcony in the future, provide for later attachment to the house in a way that does not allow water to enter the wall cavity to which the structure is attached. Any roof over a deck must be designed to support the snow load.

Source : Canada Mortgage and Housing Corporation (CMHC)