Passive fire protection is the part of a building that stops fire and smoke spreading from the place they start. It is the fire-rated walls and floors, the sealed holes where pipes and cables pass through them, the fire doors, and the dampers in the ductwork. It works without anyone pressing a button, which is why it is called passive.
This guide explains how it works, what the main systems are, how it is inspected in New Zealand, and what you are responsible for as a building owner, property manager or contractor.
What passive fire protection is, in one minute
A building is divided into fire cells. Each fire cell is boxed in by fire separations: walls and floors built to hold back fire for a set number of minutes. If a fire starts in one cell, the separations keep it there long enough for people to get out and for the fire service to arrive.
The problem is that no wall or floor stays solid. Pipes, cables, ducts and ventilation all have to pass through it. Every one of those holes is a gap in the box. Passive fire protection is mostly about closing those gaps with tested systems so the separation performs the way it was designed to.
There are two halves to fire safety in a building:
- Active fire protection detects and fights fire. Smoke alarms, sprinklers, extinguishers, hydrants.
- Passive fire protection contains fire. Fire-rated walls and floors, penetration seals, fire doors, fire dampers, cavity barriers.
Both are required. Sprinklers can fail or be overwhelmed. Passive protection is the backup that does not depend on water, power or maintenance schedules being kept.
Why it matters
- Time to evacuate. Compartmentation buys minutes. In a multi-storey building, minutes are the difference between a controlled evacuation and a rescue.
- Fire service access. Firefighters need protected stairwells and corridors to get in and get people out.
- Property and business loss. A fire contained to one tenancy is a repair. A fire that runs through the ceiling void is a rebuild.
- It is the law. The Building Act 2004 and Building Code clauses C1 to C6 set the fire performance every building must meet. For buildings with a compliance schedule, that performance is checked every year.
How buildings are divided: fire cells and fire separations
A fire separation is any wall, floor or ceiling that has a Fire Resistance Rating. Common examples:
- Walls between apartments or tenancies
- Floors between storeys
- Walls around stairwells, lift shafts and exit corridors
- Walls around plant rooms, switch rooms and rubbish rooms
- Boundary walls close to a neighbouring property
A smoke separation does a similar job for smoke only. It does not have to survive fire for a set time, but it must stop smoke moving into escape routes.
The building’s fire design says where the separations are and what rating each one needs. On an existing building, that information is in the compliance schedule and the original consent drawings.
What a Fire Resistance Rating (FRR) means
Fire-rated elements are described with three numbers, for example 60/60/60. Each number is a time in minutes:
- Structural adequacy. How long the element keeps carrying its load.
- Integrity. How long it stops flames and hot gases passing through.
- Insulation. How long the unexposed side stays cool enough not to ignite anything.
A 60/60/60 wall holds back fire for 60 minutes on all three measures. A non-load-bearing wall might be written as -/60/60. Common ratings in New Zealand buildings are 30, 60, 90 and 120 minutes.
The critical point for anyone fixing or installing fire stopping: the seal in the hole must match the rating of the wall or floor it sits in. A 60-minute wall with a 30-minute collar in it is a 30-minute wall.
We cover this in more depth in Understanding a Fire Resistance Rating (FRR).
The main passive fire systems
Fire-rated walls and floors
The separations themselves. Concrete, masonry, or fire-rated plasterboard on steel or timber framing, built to a tested system. Damage to the lining, missing screws, unsealed junctions and holes cut for later services all reduce the rating.
Service penetration seals
Where pipes, cables, cable trays, ducts and conduits pass through a fire separation. This is where most defects are found, because services get added and changed for the whole life of a building. The systems used depend on what is going through the wall:
- Fire collars and wraps for plastic pipes. Plastic melts in a fire and leaves an open hole. A collar contains an intumescent material that expands with heat, crushes the softened pipe and seals the opening.
- Fire-rated sealants and mastics for metal pipes, cables and small gaps.
- Fire batts and boards (mineral wool board with a fire-rated coating) for larger openings carrying cable trays or multiple services.
- Fire pillows for openings that need to stay accessible for future services.
- Fire-rated mortar for large or irregular holes in concrete.
- Putty pads and cast-in devices for electrical boxes and floor penetrations.
Every one of these is tested for a specific combination of wall type, service type, service size and hole size. The right product in the wrong situation has no rating at all. See service penetration fire stopping.
Openings, voids and cavity barriers
Gaps at the top of walls where they meet the floor above, voids above ceilings, joints between panels, and cavities behind cladding. These are sealed with fire-rated sealant, mineral wool, boards or purpose-made cavity barriers. See fire stopping for openings and voids.
Fire doors
A fire door is a system: the leaf, the frame, the hinges, the closer, the latch and the seals. It only works if it closes and latches on its own every time. Wedged-open doors, broken closers and missing intumescent or smoke seals are among the most common defects an inspector finds.
Fire and smoke dampers
Where ductwork passes through a separation, a damper closes automatically to stop fire and smoke travelling through the duct. Dampers need access panels and must be tested. See fire and smoke dampers.
Fire-rated duct wrap
For ducts that must keep working during a fire, such as kitchen exhaust and stair pressurisation, the duct itself is wrapped in a tested fire-rated blanket instead of being dampered. See fire-rated duct wrap.
Structural steel protection
Steel loses strength quickly in fire. Beams and columns that need a rating are protected either with fire-rated board encasement or with an intumescent coating that swells into an insulating char when heated. Both methods are tested to give the steel a set FRR.
How fire actually gets through a penetration
The video above shows it. A plastic pipe passes through a fire-rated wall. In a fire the pipe softens and melts within minutes, leaving an open hole the full size of the pipe. Flame, hot gas and smoke pass straight through into the next fire cell. A single unsealed 100 mm pipe penetration can defeat a wall that was built to last an hour.
An intumescent collar fixed around the pipe on the fire side expands many times its thickness when heated. As the pipe softens, the collar crushes it closed and fills the hole with a char that resists fire for the rated period. That is the whole idea of passive fire protection: a tested product, in the right place, that reacts on its own.
The compliance chain in New Zealand
For anyone who owns or manages a commercial or multi-unit residential building, this is the part that matters.
New buildings. The fire design is part of the building consent. Passive fire installation is usually done by a specialist subcontractor. At completion the installer provides a PS3 (Producer Statement – Construction) confirming the work was done to the tested systems in the design, and the council issues a Code Compliance Certificate.
Existing buildings. If the building has specified systems, it has a compliance schedule and needs a Building Warrant of Fitness (BWOF) renewed every 12 months. Fire separations are listed as SS15/3 and smoke separations as SS15/5. An Independent Qualified Person (IQP) inspects them and issues a Form 12A confirming they have been maintained. Without a Form 12A for every specified system, the owner cannot supply the BWOF.
When it fails. If the IQP finds defects, they will not issue the Form 12A until the defects are fixed. The council can issue a Notice to Fix. Since May 2025, a BWOF that is more than a month overdue can attract a $1,000 infringement fee, and the Building Act allows fines of up to $200,000, plus up to $20,000 a day for a continuing offence. For high-risk buildings with widespread critical defects, the IQP is required to notify the owner and the insurer in writing.
Who is responsible. The owner is responsible for keeping the building compliant. On a new build, the main contractor is responsible for making sure the fire stopping is done and documented. Trades that cut new holes for services are responsible for making sure they are sealed. In practice, the specialist who does the sealing is the one who can prove it was done to a tested system. That proof is the PS3, the tagged installations, the photos and the register.
The defects inspectors find most often
From the current IQP Code of Practice and our own inspections, these are the passive fire defects that most often stop a Form 12A being issued:
- Large holes or openings in fire-rated walls and floors
- Oversized holes around service penetrations
- Missing, wrong or badly fitted fire collars and pipe wraps
- Collars fitted over oversized holes in concrete floors
- Flaking or damaged intumescent coatings
- Unsealed penetrations from later electrical, plumbing or data work
- Fire separations that stop at the ceiling instead of continuing to the floor above
- Damaged fire-rated plasterboard
- Fire doors wedged open or with failed self-closers
- Damaged or missing smoke seals on doors
Most of these are cheap to fix and expensive to ignore. They are also invisible to anyone who is not looking above the ceiling tiles. If you have failed an inspection, read what to do when your BWOF passive fire inspection fails.
What good passive fire work looks like
You can tell compliant fire stopping from guesswork by the paperwork as much as the product.
- A tested system for the exact situation. Wall type, service type, size and hole size all match a test report or appraisal.
- Every seal labelled. A tag at each penetration showing the system, the rating, the installer and the date.
- Photographed before and after. Above-ceiling work is out of sight the day it is finished.
- A penetration register. A schedule of every seal, its location, its system and its rating, so the next IQP and the next contractor can find it.
- A PS3 where the work was consented, and clear documentation for BWOF work.
This is the standard Halt Fire works to on every job. See our projects for examples.
What passive fire work costs
For remedial work on an existing building, the range is wide: from a few hundred dollars to fix a single penetration, up to tens of thousands to bring a whole building back to compliance. What moves a job from one end of that scale to the other:
At the low end. One or two accessible penetrations, a standard tested system such as a collar or sealant, ground-floor access, and straightforward documentation. The cost is mostly the minimum call-out, the product and the paperwork.
At the high end. Dozens or hundreds of penetrations across several floors, large mixed-service openings that need board or batt systems built up in layers, oversized holes that have to be made good before a seal can be fitted, work at height or above ceilings full of services, out-of-hours access in an occupied building, and a full register, photo record and PS3 for the IQP or council.
The single biggest cost driver is usually how many penetrations there are and how hard they are to get to, not the product itself. New-build fire stopping is priced differently: per penetration or per metre from the drawings, compiled into a lump sum.
Frequently asked questions
What is passive fire protection?
Passive fire protection is the set of building elements that contain fire and smoke without needing to be activated. It includes fire-rated walls and floors, sealed service penetrations, fire doors, fire dampers, cavity barriers and structural fire protection.
What is the difference between active and passive fire protection?
Active systems detect or fight fire: alarms, sprinklers, extinguishers. Passive systems contain it: rated walls, floors, seals and doors. A compliant building needs both.
What does an FRR like 60/60/60 mean?
Three times in minutes: structural adequacy, integrity and insulation. A 60/60/60 element carries its load, stops flames and stays cool on the far side for 60 minutes.
What is a fire collar?
A metal collar containing intumescent material fitted around a plastic pipe where it passes through a fire-rated wall or floor. In a fire the material expands, crushes the melting pipe and seals the hole.
Who is responsible for fire stopping?
The building owner is responsible for the building’s compliance. On new work, the main contractor is responsible for ensuring it is done and documented. Trades that create penetrations are responsible for having them sealed. A specialist installer provides the tested system and the proof.
Do I need a PS3 for passive fire work?
For consented work, yes. The PS3 is the installer’s producer statement that the work was built to the design and tested systems. For BWOF remediation, the IQP will want documentation showing the tested system used for each repair.
What is a Form 12A?
The certificate an IQP issues each year confirming a specified system, such as fire separations, has been inspected and maintained. The owner needs a Form 12A for every specified system to renew the BWOF.
How often is passive fire protection inspected?
Buildings with a compliance schedule are inspected annually by an IQP for the BWOF. Good practice is also to check separations after any work that adds or changes services.
Can I fix passive fire defects myself?
Fire stopping only counts when it uses a tested system installed to the manufacturer’s instructions, and inspectors will ask for evidence. Untested products or the wrong product for the situation have no rating and will fail the next inspection.
What areas does Halt Fire cover?
Auckland, Northland and North Waikato. We work on new builds and existing buildings for main contractors, property managers, body corporates and building owners.
Talk to a passive fire specialist
If an IQP has flagged passive fire defects, you have a Notice to Fix, or you need fire stopping priced and documented on a new build, get in touch or call 021 288 1701. We install to tested systems, tag and photograph every seal, and supply the documentation to prove it.