If you're planning a warehouse or industrial building, you'll quickly run into the question: do I need sprinklers? For many business owners, the goal is to avoid them if possible. The cost of installing a sprinkler system can run into the hundreds of thousands — not to mention the ongoing maintenance, compliance, and water supply requirements. But is it always possible to design a warehouse without sprinklers? And if so, how?
This article breaks down when sprinklers are required, when they can be avoided, and how the fire design of your building plays a critical role in that outcome.
NOTE: The article does not address buildings that fall within the Hazardous Substances and New Organisms (HSNO) Act
CONTENTS:
Sprinklers aren’t always necessary in commercial or industrial buildings. In fact, many warehouse owners try to design them out. The reasons are practical:
In high-staffed, customer-facing environments like bulk retail (e.g. Bunnings), sprinklers make sense. They can reduce insurance costs and improve fire safety where more lives may be at risk. But in low-occupancy warehouses or manufacturing spaces, especially those used for storage only, sprinklers may not be necessary if the building is designed strategically.
For compliance with the building code, there are two key fire compliance paths in New Zealand:
C/AS2 is simpler, faster and cheaper (around $4k), while C/VM2 is more complex and costly (typically $30k–$50k), but allows more design flexibility — especially when you want to avoid sprinklers.
In warehouses and industrial buildings, fire risk groups under C/AS2 matter. Most warehouse or industrial buildings fall into one of two risk groups:
If your building falls into WS, sprinklers are generally required.
Here’s when that happens:
The first two above are the primary triggers for the WS risk group — which has a requirement for sprinklers under C/AS2.
By doing this, you stay within the WB risk group and avoid triggering the stricter WS requirements.
NOTE: Temperature controlled storage buildings have different criteria as do ‘Industrial activities’ buildings.
Yes — this is where C/VM2 comes in.
Using the Verification Method, a fire engineer can model the spread of fire and smoke within your building. They calculate how quickly a fire would grow, how long it would take for the space to fill with smoke, and how much time occupants would have to escape.
If the model shows people can evacuate safely without a sprinkler system, it can be approved by council. This method is more expensive and takes longer as it involves liaising with Fire Service as part of the initial fire report development (3+ months), but it often pays off by saving you the cost and complexity of installing sprinklers.
Designing out sprinklers isn’t just about ticking a box. Here are other factors to keep in mind:
Before finalising your design or choosing your compliance pathway, it’s worth getting expert input. For this article, we spoke with Fire Engineer Carol Caldwell, who helped answer some of the most common questions clients face when weighing up whether or not to include sprinklers.
Here are the key considerations Carol raised:
Sometimes it comes down to insurance requirements, or a client’s desire to protect business continuity in the event of a fire.
Yes, Resource Consent conditions related to water supply can still trigger a need for sprinklers, regardless of fire engineering.
Even if your fire design meets the Acceptable Solution or Verification Method, councils can still require sprinklers based on local firefighting water supply criteria (e.g. pressure and flow rates). This sits outside the Building Code but can heavily influence design.
Resource Consent water supply issues are frequently missed until late in the process.
Fire and Emergency NZ is currently updating the Code of Practice for Firefighting Water Supply, which could affect how requirements are interpreted going forward.