(1) Except as provided in Sentence (2) and Article 9.8.4.5., where a flight within a house or individual dwelling unit consists of both tapered treads and rectangular treads, all the treads shall have a uniform run when measured at a point 300 mm from the centre line of the inside handrail.
(2) Where tapered treads are located at the bottom of a mixed-tread flight described in Sentence (1), the run of the tapered treads when measured at a point 300 mm from the centre line of the inside handrail is permitted to exceed the run of the rectangular treads.