Summarises available compliance pathways for Building Code Clause C3 External spread of fire.
The Building Code is performance based. Clause C of the Building Code describes the performance criteria for Protection from Fire. Clause C3 describes Functional and Performance Requirements for fire affecting areas beyond the fire source.
Functional Requirements – Building Code Clause C3
- C3.1 Buildings must be designed and constructed so that there is a low probability of injury or illness to persons not in close proximity to a fire source.
- C3.2 Buildings with a building height greater than 10 m where upper floors contain sleeping uses or other property must be designed and constructed so that there is a low probability of external vertical fire spread to upper floors in the building.
- C3.3 Buildings must be designed and constructed so that there is a low probability of fire spread to other property vertically or horizontally across a relevant boundary.
There are two Performance Clauses that describe the constraints for control of external vertical fire spread:
- Clause C3.5 – limiting the vertical spread of fire
- Clause C3.7 – covering the ignitability of external wall cladding materials.
Three pathways are available to demonstrate compliance with the Building Code Performance Requirements: Acceptable Solutions, Verification Methods and alternative solutions.
The following table outlines the Performance Requirements of the New Zealand Building Code and summarises the associated compliance pathways:
Compliance Pathways for New Zealand Building Code Clause C3 - External Spread of Fire.
|Building Code Performance Requirements|
|Buildings must be designed and constructed so that fire does not spread more than 3.5 m vertically from the fire source over the external cladding of multi-level buildings.||External walls of buildings that are located closer than 1 m to the relevant boundary of the property on which the building stands must either:
|Compliance Pathway – Acceptable Solutions C/AS2 to C/AS7|
|The Acceptable Solutions (C/AS2 to C/AS7) contain three means of demonstrating compliance:
|Compliance Pathway – Verification Method C/VM2|
|The Verification Method (C/VM2) contains four means of demonstrating compliance:
|Compliance Pathway – Alternative Solution|
|An alternative solution proposal must be provided that justifies how the design of the building will not result in fire spread of more than 3.5 m vertically from the fire source over the external cladding of multi-level buildings.||