The foundation supports the entire house and its occupants. Upon conception, it must also take into account the possible weight overloads such as snow. The installation of brick or stone as siding should also be taken into consideration during the design stage of the foundations. Although the Building Code does not require mandatory installation of rebar steel in foundation walls, it is strongly advised to do so.

The foundations are cast in reusable wooden forms designed for this purpose. The frames (sub frames) for windows and exterior doors are installed during assembly of the formwork. Prefabricated windows can also be inserted in the forms according to plan. The concrete must be poured continuously without interruption. Air pockets must be eliminated during the pour and concrete must be directed under door and window frames.

In cold weather, freshly pored foundations must be protected against frost with insulating blankets. Additives can also be used to accelerate the concrete cure. In very hot weather, concrete should cure as slow as possible.