Page 65 - Build 161

Fire safety
● remove the term ‘structural stability’ from Building Code clause C6
● amend Veri cation Method C/VM2, including adding more speci c
criteria for tall buildings (>60 m building height)
● issue guidance under section 175 of the Building Act to provide a framework for undertaking Alternative Solutions for re safety design.
More flexibility in use of Material Group Numbers
Currently, the re safety requirements for internal surface nishes including walls, ceilings and floors are prescribed at Building Code level. The speci cs within this clause removed the ability to undertake performance-based design in this area.
The re programme review identi ed that this requirement was overly restrictive and does not allow for equivalent measures or speci c uses.
The proposal is to remove the prescriptive requirements from the Building Code level and retain and clarify the criteria within the Acceptable Solutions and Veri cation Method.
This will result in changes to Building Code clause C3.4, Acceptable Solutions C/AS1–7 and Veri cation Method C/VM2.
Moving structural stability requirement
The existing Code clause C6 calls for structural stability to be maintained during and after re. The re regulatory framework review concluded that the stability of structure is the role of the structural engineer, therefore the re engineer’s role became unde ned.
Proposals in the consultation aim to help separate the roles and responsibilities of the structural and re engineers to provide clarity. They would modify the Building Code, moving the requirement for structural stability from clause C6 Structural stability to clause B1 Structure.
The consultation proposed changes that would include modi ca- tions to Building Code clause C6 and resultant changes to de nitions and provisions in Acceptable Solutions C/AS1–7 and Veri cation Method B1/VM1.
Verification Method C/VM2 updated for tall building safety
Veri cation Method C/VM2 provides a framework for re safety design in New Zealand. MBIE included a proposal in its recent consultation to update the Veri cation Method and include more safeguards for tall buildings.
The proposal put forward included speci c additional considera- tions for tall buildings such as escape provisions, re- ghting access and facilities and appropriate re resistance rating of structure. The aim of the updates to the Veri cation Method is to ensure safety is paramount in tall buildings and that the requirements are not overly restrictive for other types of buildings.
More clarity for Alternative Solutions
The New Zealand Building Code is a performance-based regulation, which allows designers the freedom to propose innovative or Alternative Solutions provided they comply with the performance requirements of the Building Code.
Previously, there has been little guidance for demonstrating and assessing Alternative Solutions for compliance with the Building Code, especially for Alternative Solutions to Code clauses C1–6.
The re programme concluded that a framework for demonstrating and assessing Alternative Solution proposals is required to assist designers and building consent authorities.
The proposed framework is intended to be issued as guidance under section 175 of the Building Act.
Two other priority projects
Two separate priority projects, also originating from the fire programme, were undertaken by MBIE over the past year. Acceptable Solutions review
MBIE has drafted a proposal to merge Acceptable Solutions C/AS2–7 into a single document to be known as C/AS2. This idea received widespread support from stakeholders during a series of workshops in 2016.
To ensure the amalgamated document works in practice, MBIE conducted a pilot scheme that concluded in June 2017. Full public consultation on this proposal is expected later in 2017.
Guidance for supported housing
The supported housing project run by MBIE has been working closely with representatives from the supported housing sector.
The Ministry of Health, building consent authorities and the New Zealand Fire Service helped to develop a residential community housing design guide for re safety. It is intended for housing funded by the Ministry of Health or with a recognised audit process.
The guidance document will be issued under section 175 guidance, and this is expected to go out for industry consultation later this year.
Note MBIE will continue to review and re ne aspects of the re regulatory system as part of its regulatory stewardship role.
Build 161 — August/September 2017 — 63
FEATURE SECTION