DZ4510:2021 Hydrant Systems Review

Hi all
I hope that all praticing fire designers have had a chance to look at DZ4510.
The draft as it stands does not comply with NZBC C5.5, nor does it comply with Building Act S.18. In the Definitions, “Approved” means approved by the building consent authority (BCA) in accordance with the NZ Building Code (NZBC).
The problems are caused by the attempt to include SNZ PAS 4509 (which is not a listed compliance document) in DZ 4510, thus including water supplies, which is not a requirement of C5.5, plus the inclusion of C5.6. As NZS 4510:2008 is a listed means of complying with C5.5, why is DZ4510 not following the same path?
The draft allows for 2 parties to be consulted and agreed during the hydrant design and supply process, being the HSC and FENZ. In addition, while it is very convoluted, it appears in Appendix K that FENZ can totally over ride the standard any time they choose.
The draft attempts to constrain the size of buildings, including cold storage, and to supply fire rated access to any hydrant - both internal and external.
There does not appear to be any attempt to introduce a risk assessment associated with the provision of an internal hydrant system. If a large rack storage warehouse requires internal hydrants, in reality FENZ will not enter the building on fire, as they will not be able to see their way due to smoke, plus the possibility of stock falling on them exists. FENZ proposes to address this problem by requiring fire rated tunnels from the exterior of the building to the hydrant location. What does this have to do with the requirement to have a means to deliver fire fighting water?
Appendix J, which is informative, essentially gives FENZ - who are not an approving authority - the ability to have total control of any alternative design.
The draft standard as published should not be published, as it does not comply with C5.5, nor does it comply with S.18 of the Building Act.
Comments please

Hi Paul
We struck a similar problem on the sprinkler standard where the standard attempted to close loop holes in the acceptable solutions in respect of determining when dual water supplies should be required.
Problems occur when technical standards try and overcome deficiencies in building code documents.
What is effectively being said here is that because C/AS2 and C/VM2 do not effectively address NZBC clause C5.5 then DZ 4510 is going to address it.
Whilst MBIE are now actively participating in the standards committees, their ability to effect the required changes in the compliance documents in a timely manner, to allow the standard to remain a technical document, is limited.
The danger here is that compliance with NZS 4510 get wrapped up in other legislation outside of the NZBC and the Building Act and creates unintended consequences which nobody can control; not even FENZ even if they want to.
I suspect that the committee is concerned about interesting alternative fire engineering designs that from time to time occur, where the considered interests of FENZ are not taken into account.
We have variable fire engineering efforts and variable FENZ response to building hydrant proposals.
With one notable exception I have found FENZ to be very pragmatic in their approach to hydrant locations.
I would strongly resist any approach to incorporate building criteria in the NZS 4510 standard and push hard for MBIE to address any shortcomings in their compliance documents.

Thanks for your comments. I cannot stress enough how important it is for people to make a formal comment on these issues. I encourage all members to submit via the SNZ website:

Hopefully our brief presentation yesterday highlighted the proposed changes, the committee can only discuss issues if they are raised via this formal process, please do not stay silent if you disagree with what is written in the DRAFT.

Cheers, Jeff.

Hi Jeff,

I don’t think it’s a matter of disagreeing with the draft rather than the fact that the draft is fundamentally wrong. A design standard purpose is to provide a fire safety system for a building not to ensure the utilities are sufficient for that system. The provision of water reticulation to a site is outside of the Building Act and has no place in a standard deemed to comply with the building code. The provision of water, power and all other utilities needs to addressed under the Resource Management Act with any issues taken up with Department of Internal Affairs. Yet again designers are being asked to rectify weakness in other legislation and putting unnecessary costs on the building owner.


You need to formally send your objection to the standards committee if you wish them to consider your statement. If enough people say the same thing it will lend weight to the suggestion.

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Hi All,

Yes, please make public comments on the draft (link as per Jeff’s comment). Clear and concise with regard to the aspect you want to comment on. I suggest that it is important to look at the document holistically and ensure you capture within your comment any alternative compliance pathways offered in the draft that caters for a change in the normative parts of the Standard.

In seeking feedback from the industry I would expect the committee will be interested whether any of the proposed changes of significance are considered (a) robust, and (b) have the commercial acuity to work within the current building design/construct process.

Cheers, Pete.

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