An alternative solution needs to consider which Building Code performance clause or clauses are affected by the specific aspects of the design, and provide appropriate justification to demonstrate compliance.
Depending on the proposed design, the engineer/designer may need to consider more than one Building Code clause. The key is to ensure the assessment of applicable Code clause(s) is holistic, and captures all relevant performance clauses that might be affected – some of which might not be immediately obvious.
Objectives – life safety, protection of other property, and firefighting
Clause C1 sets out the three main objectives of the fire clauses, which relate to:
- life safety
- protection of other property
- firefighting operations.
While these are only objectives and not performance requirements in their own right, they provide the main focus of any alternative solution.
Fire clause performance requirements
The rest of the fire clauses step through a number of requirements for:
- preventing fire occurring (C2)
- limiting fire spread (C3)
- assisting the evacuation of occupants (C4)
- safeguarding firefighters (C5)
- maintaining the stability of the structure (C6).
Fire clause application
An alternative solution can relate to one or more objectives and fire safety clauses. The following table provides assistance for linking the objectives to various fire safety clauses.
For all alternative solution designs, the relevant clauses to be addressed are to be agreed with the key stakeholders through the Fire Engineering Brief process.
Table: Building Code objectives for protection from fire and the relevant performance clauses
|Life safety||Limiting the temperature of appliances to prevent fire ignition.||C2|
|Internal surface finishes shall have minimum reaction to fire.||C3.4|
|Minimum toxicity and visibility shall be provided for the period of escape.||C4.3, C4.4|
|Fire safety systems required for life safety shall be reliable with regard to the likelihood and consequence of failure.||C3.9, C4.5|
|Structural systems supporting fire rated escape routes shall remain stable.||C6.2|
|Protection of other property||Vertical spread of fire cladding is limited to 3.5 m.||C3.5|
|External spread of fire across the boundary is limited in radiant heat flux.||C3.6, C3.7|
|External fire spread limited from large firecells.||C3.8|
|Structural systems supporting fire rated elements shall remain stable.||C6.2, C6.3|
|Firefighting operations||Safe access to the building shall be provided for fire service vehicles.||C5.3, C5.4|
|Adequate provision of water must be made for firefighting operations.||C5.5|
|Safe access must be provided for firefighters to the floor of fire origin.||C5.6|
|Information must be provided for Fire and Emergency NZ (FENZ).||C5.7|
|Fire safety systems for protection of firefighters shall be reliable.||C5.8|
|Any structural systems for access for firefighting operations shall remain stable.||C6.3|