Under NZBC Clause D1, there are a variety of stair types with differing requirements for stairway pitch, riser & tread lengths. This is so that people moving into, within or out of buildings can do so safely. For example, Table 6 below has the design limits for each type of stair.
A summary of each type of stair listed in Table 6 is noted below:
Accessible stairway:
A stairway having features for use by people with disabilities. Accessible buildings needs at least one accessible stairway leading off an accessible route even if a lift is provided.
Common stairway:
A stairway having features for use by the public whether as of right or not, and is not a private stairway, service stairway or accessible stairway.
Private stairway:
A stairway having features for use by the occupants of a single household unit.
Secondary private stairway:
A private stairway other than a main or minor private stairway, intended to provide access to another floor containing only bedrooms, bathroom or similar accommodation.
Service stairway:
A stairway having features for use infrequently by service personnel to gain access to spaces for the purposes of maintenance and the movement of goods.
You can find more details on NZBC clause D1 requirements at: https://www.building.govt.nz/building-code-compliance/d-access/d1-access-routes/
Save time, resource and ease of installation when specifying Moddex guardrails or balustrades. Consult the Compliance Tip or contact us on 1800 663 339 (Australia) or 0800 663 339 (New Zealand).