Technical Booklet H Stairs Ramps Guarding and Protection from Impact·Page 32·Diagram 3.9
Stair dimensions and step profiles
Diagram 3.9 specifies dimensional requirements for stairs including rise heights (150-170 mm), going (250 mm minimum), flight limits (12 rises maximum), handrail heights (900-1100 mm), and step profile details to minimize tripping hazards.
Diagram 3.9 Details of stairs: not more than 12 rises in any flight; rise not less than 150 mm and not more than 170 mm; going not less than 250 mm; not less than 900 mm and not more than 1000 mm above pitch line; not less than 900 mm and not more than 1100 mm handrail height; not more than 25 mm overlap; 60° minimum angle; examples of suitable step profiles with solid nosings and suitable rounding (note: excessive rounding of the nosings reduces the effective going).
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet H - Stairs Ramps Guarding and Protection from Impact.pdf