(1) The unobstructed width of a hallway within a dwelling unit shall be not less than 860 mm, except that the hallway width is permitted to be 710 mm, where,
(a) there are only bedrooms and bathrooms at the end of the hallway furthest from the living area, and
(b) a second exit is provided,
(i) in the hallway near the end furthest from the living area, or
(ii) in each bedroom served by the hallway.