Combustible Cladding on Auckland Apartments: Rules and Options

If you sit on a body corporate committee or own a commercial building, the words combustible cladding tend to arrive in one of two ways: a line in a fire report, or a question from your insurer. Either way, the issue is the same. Some buildings put up in the 1990s and 2000s were clad in aluminium composite panels with a combustible core, the material made notorious by London's Grenfell Tower fire in 2017, and New Zealand has since tightened how the Building Code treats it. Here is what the rules actually say, what they do not say, and what the options look like for an Auckland building that has it.

What ACP is, and why it became an issue

Aluminium composite panel, ACP, is a sandwich: two thin aluminium skins around a core. The core is the whole question. Mineral-filled cores are fire-resistant. Older polyethylene (PE) cores are combustible, and on a tall facade a combustible core can let fire race up the outside of a building, which is what the world watched happen at Grenfell. The panels look identical from the street. The difference is inside them, which is why identification takes an engineer rather than a pair of binoculars.

After Grenfell, New Zealand's main councils reviewed their building stock to find where ACP had been used. In Auckland, that meant checking hundreds of buildings. The reviews found ACP on a subset of them, mostly in limited areas, and at the time none were judged to pose an immediate danger, in large part because the extent was small or the buildings had sprinklers and other fire systems. The Ministry of Business, Innovation and Employment oversaw the response and then changed the rules for what can go on a facade.

The current rules: restricted, not banned

New Zealand has not banned ACP outright. What it has done is tighten the fire-performance requirements that any external cladding system has to meet, which in practice pushes combustible-core panels out of the situations where they are dangerous.

The framework sits in the Building Code's protection-from-fire clauses (C1 to C6, with clause C3 covering fire spreading beyond its source) on building.govt.nz. A cladding system shows it complies through the Acceptable Solutions (the C/AS documents), the C/VM2 verification method, or a specifically justified alternative design. Following MBIE's 2019 guidance on the performance of external wall cladding systems and the amendments that came with it, the practical position is:

• Cladding is assessed as a system, panels, fixings, cavity, insulation together, not as a lone product.
• On buildings above roughly 7 metres, cladding systems generally need fire test evidence demonstrating their performance, where previously taller sprinklered buildings had more latitude.
• The requirements are strictest where people sleep, apartments, hotels, aged care, because occupants may not be awake to respond to a facade fire.

The net effect: on a mid-rise or high-rise residential building, a PE-core ACP system will almost never satisfy the current requirements, so any new work or replacement effectively designs it out.

What it means if your existing building has it

This is the part owners most often get wrong in both directions, either panic or complacency, so it is worth being precise.

There is no blanket order to strip ACP. Existing buildings are not automatically non-compliant just because the rules have tightened since they were built. New Zealand manages the existing stock through risk assessment rather than a national removal mandate.

But the issue does not sit inert either. Three forces act on it. First, councils hold powers under the Building Act 2004 dangerous-building provisions (sections 121 and 124): if a building's cladding, in its context, makes it dangerous, the council can require work. Second, fire risk assessments and building surveys increasingly flag ACP, which puts it on the body corporate's agenda whether or not anyone wanted it there. Third, insurers and lenders treat combustible cladding as elevated risk, and that pressure often moves faster than any regulator.

Identification comes first, and it is specialist work. Whether panels are the high-risk type cannot be judged by looking at them. A facade engineer or fire engineer identifies the system, reviews the building's documentation, and where needed takes core samples for testing to establish what the panels actually are, then assesses what they mean for this building: how much of the facade they cover, where they sit relative to escape routes, what sprinklers and alarms are in place. Two buildings with the same panel can carry very different risk.

What replacement involves

Where the assessment concludes the cladding should go, the replacement is consented building work, designed by the fire engineer (and usually a facade engineer) to meet the current C-clause requirements with a non-combustible system, then built, inspected and signed off through to a Code Compliance Certificate. On an occupied apartment or commercial building that is a staged exercise: access from swing stages or mast climbers, the building kept weathertight and occupied face by face, and the fire safety of the escape routes maintained throughout the work.

For a body corporate, the sequence usually runs: engineer's identification and risk assessment, a decision at committee and then general-meeting level, funding through the long-term maintenance plan or a levy, then the consent, the replacement and the sign-off. The building work is the visible part; the governance and funding usually take longer.

The sensible middle path

The honest position on ACP sits between the two reflexes. A building should not be stripped in a panic because a report contains the word cladding, the core type, the extent and the context matter, and plenty of ACP installations are low-risk. Equally, an insurer's question or a flagged fire report should not be left to age in a drawer, because the pressure around combustible cladding only moves in one direction, and a body corporate that gets ahead of it controls the timeline and the cost in a way that one responding to a council notice does not.

The first step is cheap relative to everything downstream: establish what is actually on the building. If your Auckland apartment block or commercial building has had ACP flagged, or you want it identified properly before anyone starts talking about replacement, an assessment of the facade is the place to start.