Insurers will assess buildings with external combustible claddings for greater fire risks as policies are renewed, the Insurance Council of New Zealand (ICNZ) warns.
ICNZ chief executive Tim Grafton said the effect on policies would depend on the type of panels and the extent of their use on the exterior of buildings, according to a report on the news website, stuff.co.nz.
The comments are made as the UK government decides to ban combustible cladding on the outside of high rise buildings in response to the 24-storey Grenfell Tower fire tragedy in June 2017.
There are three types of panels: those with a 100% polyethylene core, those that are fire-rated and "somewhat" less flammable, and non-combustible panels.
Insurers have the greatest concerns about high rise buildings with attached aluminium composite paneling (ACP) running all the way up with a combustible polyethylene core.
If a fire started for instance on a balcony it could spread rapidly up a building in a short time, start to break windows and enter the building on many levels at once.
Sprinkler systems are designed to contain one seat of fire for a short time before the fire service arrives but not necessarily to contain fires on several levels at once.
Building owners in doubt about what the core of the aluminium panels are advised to get them tested, Mr Grafton said.
Mr Paul Hobbs, acting manager building system assurance, at the Ministry of Business, Innovation and Employment (MBIE), said New Zealand buildings are required to have multiple lines of defence for fire safety, so if one part of the fire system did not perform as expected, other parts would continue to maintain life safety.
New Zealand multi-storey residential buildings with ACP cladding typically had active and passive fire protection systems.
Active fire protection includes fire detection, alarm systems and sprinkler systems, and passive fire protection is fire-rated construction, for example fire-rated plasterboard walls.
"What this means, is that the use of ACP panels in New Zealand buildings does not run the same risk as that of buildings such as Grenfell Tower in the UK," Mr Hobbs said.
"For example a building similar to Grenfell Tower constructed in New Zealand would have smoke detection, a building wide alarm system, an automatic sprinkler system and an all-out evacuation plan. The Grenfell tower did not have all of these features."
MBIE had asked metropolitan councils to determine the prevalence of ACP in high rise building in NZ, Mr Hobbs said.
"Auckland Council has recently stated there are 116 buildings with ACP in their jurisdiction and Wellington City Council has 112. Christchurch has found 28 buildings with combustible panels and 18 others with unidentified or semi-combustible panels.
"All councils have stressed they consider none of these buildings to be dangerous," Mr Hobbs said.
However, Mr Grafton said the insurance industry had found many instances in New Zealand of passive fire safety systems not complying with safety standards. There was no requirement for installers to have any qualifications. The industry knew of numerous examples of work on buildings after they were built that had damaged the passive fire protection systems, he said.