The Ontario Building Code | Adjustments to Footing Widths for Interior Walls
9.15.3.6. Adjustments to footing Widths for interior Walls
(1) The minimum strip footing widths for interior loadbearingmasonry walls shown in Table 9.15.3.4. shall be increased by 100 mm for each storey of masonry construction supported by the footing.
(2) footings for interior non-loadbearing masonry walls shall be not less than 200 mm wide for walls up to 5.5 m high and the width shall be increased by 100 mm for each additional 2.7 m of height.