Lightning protection New Zealand: the standard, the law and IEC 62305
New Zealand did not follow Australia to AS 1768:2021. Its law still names the 2007 edition for explosives stores and large flammable liquid tanks.
Lightning protection in New Zealand still follows AS/NZS 1768:2007, the joint standard that Australia replaced with the Australian-only AS 1768:2021.
The two countries had shared one lightning standard since an interim joint edition in 2003, so the split catches Australian firms out. When the revision arrived in 2021, Standards Australia and Standards New Zealand agreed to publish it for Australia alone. New Zealand kept the 2007 edition, and its law still names that edition for the few sites where lightning protection is a legal duty. For the design rules, buy AS/NZS 1768:2007 from Standards New Zealand.
Last checked 30 September 2026. Every legal statement links to the official text on the New Zealand legislation site, read that day.
Which lightning protection standard applies in New Zealand?
Three documents come up on New Zealand projects. Only one of them is the current national standard.
Current in New Zealand
The joint Australian and New Zealand standard. Standards New Zealand lists it as remaining current within New Zealand, and the Hazardous Substances Regulations 2017 cite it by its 2007 date.
Australia only
Standards Australia's revision, published in December 2021. It supersedes the 2007 edition in Australia and carries no New Zealand designation. It is not the national standard for a New Zealand site.
By specification
The international series. A New Zealand project uses it when the specification, the owner's engineering standards or an insurer names it. That is a contract choice. It does not change which standard is current nationally.
We hold AS 1768:2021 and the IEC 62305 series, but not AS/NZS 1768:2007. So this guide describes the 2007 edition's status and where the law refers to it, not its technical content. For its content, buy it from Standards New Zealand. For how the two editions compare where we can check them, see AS/NZS 1768:2007 against AS 1768:2021.
Why AS 1768:2021 is not a joint standard
The answer is in the preface of AS 1768:2021 itself. It was written by the Australian members of joint committee EL-024, Protection Against Lightning, and it was meant to supersede AS/NZS 1768:2007. The preface then records that the two standards bodies consulted stakeholders on both sides of the Tasman and decided to issue the revision as an Australian Standard, not a joint one. The publication history printed on the page before the preface shows the lineage: an interim joint edition in 2003, a joint edition in 2007, then a revision redesignated as AS 1768:2021.
The preface gives no reasons for the decision, so treat any explanation you read elsewhere as opinion. What matters in practice is the outcome. Standards New Zealand's product page for the 2007 edition says the development of an Australian-only 2021 edition left the 2007 edition current in New Zealand.
The 2021 edition was a large change. Its preface describes it as a major revision that aims to line up with IEC standards and to accept that many modern buildings protect themselves. Clause 2.5.3 describes its risk method as a simplified form of the IEC 62305-2 approach, based on assumptions for general Australian conditions, and a calculation spreadsheet comes with the purchased standard. None of that carries across to a New Zealand project by default. If you work on both sides of the Tasman, you are now working to two different editions. For the Australian side, see the lightning protection standards map for Australia and AS 1768:2021 explained section by section.
Is lightning protection required by law in New Zealand?
For most buildings, no general legal rule requires lightning protection in New Zealand. For two kinds of hazardous substance site, the law does. Both duties sit in the Health and Safety at Work (Hazardous Substances) Regulations 2017 (LI 2017/131), administered by the Ministry of Business, Innovation and Employment. We read the version dated 30 July 2026. The duty falls on the PCBU, the person conducting a business or undertaking, that manages or controls the site.
- Explosives locations. Regulations 9.24 and 9.25 require an earthing system and lightning interceptors at a hazardous substance location holding class 1 substances above set quantities.
- Large flammable liquid tanks. Regulation 17.9 requires certain above ground stationary tanks for flammable liquids to follow AS/NZS 1768:2007 or a safe work instrument.
The Building Code says nothing on lightning. We searched the full text of Schedule 1 of the Building Regulations 1992, which is the Building Code, and the word lightning does not appear in it. Clause F3, Hazardous substances and processes, sets performance requirements for spaces where hazardous substances are kept, and MBIE's page for F3/VM1 says that verification method points back to hazardous substances legislation. We found no Building Code clause, acceptable solution or verification method in force that requires a lightning protection system on an ordinary building.
On most New Zealand projects the requirement comes from the client, an insurer, a lease or a risk assessment, not statute.
What the law fixes at an explosives location, whatever edition you buy
These two regulations are the most specific lightning rules we found in New Zealand legislation. The 10 ohm earth, the 20 m sphere and the 30 degree cone below are the regulations' own values, not a standard's. They apply to class 1 substances, explosives, but not to fireworks.
When the duty starts
Only above a threshold quantity at the location: more than 50 kg of class 1.1 or 1.5 substances, more than 100 kg of class 1.2 or 1.6, or more than 200 kg of class 1.3.
An earthing system
It must run between the air above the location and earth, measure under 10 ohms to earth before any metal structures or service conduits are bonded to it, and sit far enough from the explosives that static building up on it cannot discharge into them.
Lightning interceptors, placed one of two ways
Either the whole location falls inside a cone or plane drawn at 30 degrees from vertical from the top of the interceptors, or it falls outside the arc of a 20 m radius sphere rolled over the location and the interceptors. The regulation points to figures 4.1 and 4.2 in section 4 of AS/NZS 1768:2007 for the picture.
When no separate interceptors are needed
Where the whole outer skin of the location already serves as its lightning earth, the regulation drops the need for separate interceptors.
Breaching either regulation is an offence, with a fine of up to $10,000 for an individual and up to $50,000 for any other person (regulation 9.24(3) and 9.25(3)). Regulation 9.23(1)(g) also requires a lightning conducting system meeting both regulations wherever the quantity of class 1 substances calls for one. Do not swap in a sphere radius from AS 1768:2021, NFPA 780 or IEC 62305 on the strength of it being a more recent standard.
Flammable liquid tanks and the 2007 standard
Regulation 17.9 applies to an above ground stationary tank that stores class 3.1A or 3.1B flammable liquids and has a safe fill capacity above 60 cubic metres. The PCBU responsible must make sure the tank is designed, built, installed and operated either to sections 1 to 5, 7 and 8 of AS/NZS 1768:2007 (the regulation prints it as NZS/AS 1768:2007), or to the requirements of a relevant safe work instrument. The same fines apply as for regulations 9.24 and 9.25.
This is the clearest reason a New Zealand tank farm cannot simply move to AS 1768:2021. The regulation names the 2007 edition and particular sections of it. A design to the 2021 edition, however current it is in Australia, is not what the regulation asks for. Unless a safe work instrument provides another route, the 2007 sections are the legal baseline.
Regulation 17.10, next to it, deals with static electricity rather than lightning. It applies to above ground tanks of class 3.1A, 3.1B or 3.1C liquids and calls for static to be controlled to AS/NZS 1020:1995 or a safe work instrument. For how the US and Australian standards treat tanks and hazardous sites, see NFPA 780 on flammable liquid tanks and lightning protection for oil, gas and hazardous sites.
When a New Zealand project uses IEC 62305 instead
A New Zealand project uses IEC 62305 when someone with authority over the project says so. In practice that means one of three people. A multinational owner whose group engineering standards name IEC 62305 for every site. An insurer or lender that asks for an IEC 62305 risk assessment. Or a designer whose specification adopts it because the facility, such as a data centre or a telecommunications site, carries sensitive electronics that Part 4 of the series addresses in depth.
When that happens, IEC 62305 becomes the design basis by contract. It does not become a New Zealand Standard, and nothing in the regulations we read refers to it. Two consequences follow. First, the risk assessment is run to IEC 62305-2 in full, on the current 2024 edition, not blended with the Australian method. Second, a regulation that names AS/NZS 1768:2007 still applies. An explosives store designed to IEC 62305 must still meet the 20 m sphere or 30 degree cone of regulation 9.25 and the earthing rules of regulation 9.24.
For the international series and how countries adopt it, read what IEC 62305 is and IEC 62305 around the world.
Which standard applies, situation by situation
Each row names the source that decides it. Where the law names a standard, the law wins over preference.
| Situation | Standard or rule | Source |
|---|---|---|
| General lightning protection design for a New Zealand building | AS/NZS 1768:2007, the current national standard | Standards New Zealand |
| Hazardous substance location with class 1 explosives above the threshold (fireworks excluded) | Earthing system and lightning interceptors as regulations 9.24 and 9.25 set out | Regulations 9.24 and 9.25, LI 2017/131 |
| Above ground tank of class 3.1A or 3.1B liquids, safe fill capacity over 60 cubic metres | Sections 1 to 5, 7 and 8 of AS/NZS 1768:2007, or a safe work instrument | Regulation 17.9, LI 2017/131 |
| Ordinary building with no hazardous substance duty | No lightning rule in the Building Code; protection follows the specification or a risk assessment | Building Regulations 1992, Schedule 1 |
| Specification, owner standard or insurer names IEC 62305 | IEC 62305, with IEC 62305-2:2024 for the risk assessment, plus any regulation above that also applies | The project contract documents |
| A site in Australia | AS 1768:2021, which superseded AS/NZS 1768:2007 there | AS 1768:2021 Preface |
Practical steps for a New Zealand project
Settle the basis for lightning protection on a New Zealand project in writing, before anyone draws an air terminal or runs a risk figure.
Check for a legal duty
Ask whether the site holds class 1 explosives above the 9.24 thresholds, or has a class 3.1A or 3.1B tank over 60 cubic metres. If so, the regulations set the minimum and name the 2007 standard.
Read the specification
Find which standard the client, owner group or insurer names. If it says IEC 62305, that is the design basis on top of any legal duty. If it names nothing, AS/NZS 1768:2007 is the national reference.
Buy the right edition
Get AS/NZS 1768:2007 from Standards New Zealand, or IEC 62305 from the IEC. An AS 1768:2021 copy bought for Australian work is the wrong document for a New Zealand basis.
Run one risk method
Assess risk with the method of the standard you are designing to, on its current edition. Do not borrow tolerable values or coefficients from a different standard to fill a gap.
Record the basis in the report
State the standard and edition, the regulation that applies, and why. A reader on a later audit should not have to guess which of three documents you used.
Get the compliance certificate
At an explosives location, arrange the compliance certificate that regulation 9.26 calls for. It covers the location requirements of regulation 9.23, which include the lightning conducting system of regulations 9.24 and 9.25.
What goes wrong on New Zealand lightning protection work
- Treating AS 1768:2021 as the New Zealand standard. It is not. An Australian firm working in New Zealand should switch reference documents at the border, not carry its home edition across.
- Assuming the newest edition satisfies the regulations. Regulations 9.25 and 17.9 name AS/NZS 1768:2007. A design to a later or different standard needs to show it still meets what those regulations actually require.
- Missing the thresholds and exclusions. Regulation 9.24 applies only above the class 1 quantities it sets, and never to fireworks. Regulation 17.9 applies only to class 3.1A and 3.1B tanks over 60 cubic metres. Check the site inventory before you conclude a duty does or does not exist.
- Reading the Building Code's silence as permission to skip. The Building Code does not mention lightning, but a specification, an insurer or the owner's risk policy often does. No legal duty is not the same as no requirement.
- Mixing standards in one design. Taking the sphere radius from one document, the earthing rules from another and the risk method from a third produces a design that conforms to none of them. Pick the basis, then follow it.
- Calling IEC 62305 the New Zealand standard. The current national standard is AS/NZS 1768:2007. Where a project uses IEC 62305, write it in the report as the contract basis, with its part and edition.
What Lumex runs for a New Zealand site
Lumex runs three risk methods: IEC 62305-2:2024, NFPA 780-2026 Annex L and AS 1768:2021. It does not run the AS/NZS 1768:2007 method, so it is not the tool for an assessment that must be made to the current New Zealand standard. Running the Australian 2021 method for a New Zealand site would give you a report on the wrong basis, and Lumex does not offer it as a stand-in.
Where a New Zealand project specifies IEC 62305, run it in Lumex as an IEC 62305-2:2024 assessment. You get the risk and the frequency of damage from the structure, its surroundings and its services, compared against the tolerable values, with the working behind every figure and a report the signing engineer approves.
Lumex does not design the protection system and does not certify a structure. It does not issue the compliance certificate that regulation 9.26 calls for at an explosives location. Any regulation that names AS/NZS 1768:2007 still has to be met separately.
Your next step: if your specification names IEC 62305, start an IEC 62305-2:2024 assessment in Lumex and record the regulation that still applies beside it in the report. To see which standard Lumex runs for which region, start at the standards overview. For Australian sites, see how Lumex runs AS 1768:2021.
Related reading: compare the editions in what changed from AS/NZS 1768:2007 to AS 1768:2021, then read AS 1768:2021 explained and the standards map for Australia. For the international series, see what IEC 62305 is and NFPA 780 compared with IEC 62305. For the risk assessment itself, read how a lightning risk assessment works.
Questions answered
What is the lightning protection standard in New Zealand?
Does AS 1768:2021 apply in New Zealand?
Is AS/NZS 1768:2007 still current in New Zealand?
Can I use IEC 62305 in New Zealand?
Is lightning protection required by law in New Zealand?
Do hazardous substance sites in New Zealand need lightning protection?
Which rolling sphere radius do New Zealand explosives stores use?
Lumex computes the method of the standard you choose, IEC 62305-2:2024, AS 1768:2021 or NFPA 780-2026, and shows the working. It does not certify a structure. You may not issue or submit a Lumex output until a competent person, qualified where the structure is located, has reviewed the inputs and the result and signed it.
AS 1768:2021 Table 2.1 sets a tolerable value for each type of loss, and the owner chooses the one for economic loss. Every AS 1768 assessment in Lumex states the values that applied.
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