The new earthquake-prone building regime, in force since 1 July, carries potentially serious health and safety implications which property owners and employers need to be aware of.
These arise from the interface of the regime with the Health and Safety at Work Act. We outline the issues and look at their practical effect.
- The new earthquake-prone regime applies to parts of buildings – variously referred to as “components”, “building elements” and “secondary structural and non-structural elements” (SSNS).
- A building can be assessed as earthquake-prone if any of these elements poses a significant life safety hazard.
- Historically, compliance with the seismic design of SSNS has been limited and variable.
- The new system has gaps which mean that non-compliance of existing SSNS may not be identified.
- The WorkSafe Position Statement on enforcement may not provide employers and owners with the protection they think it does.
- Employers and owners need to engage to ensure that they are each meeting their respective obligations under the HSWA in relation to SSNS or parts of buildings. To fail to do so is to risk prosecution.
The new system
The structure is shown in the figure below:
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Parts of buildings
Much of the commentary on the new system has focussed on the costs involved in upgrading the structure of buildings to meet the new standards, and who should bear those costs. But the extension to parts of buildings and the interface with the Health and Safety at Work Act 2015 (HSWA) has attracted relatively little attention – although they carry significant risk of liability.
- define “part” of a building as an individual member or element or section of a building’s structure (as distinct from the building structure as a whole), or a non-structural element
- adopt the Building Act definition of “building element” – being any structural or non-structural component and assembly incorporated into or associated with a building, such as fixtures, services, drains, permanent mechanical installations for access, glazing, partitions, ceilings and temporary supports
- define SSNS as including pre-cast concrete panels, curtain wall framing systems, stairs and supports for significant building services items, and
- specify the types of building elements and situations most likely to pose a significant life safety hazard (an unavoidable danger to which a number of people are exposed) and therefore need to be included in engineering assessments.
The %NBS rating for a building as a whole now takes account of, and may be governed by, the scores for individual building elements. It represents the minimum of the earthquake scores assessed for the global performance of the primary structure for each principal direction and the earthquake score for each individual SSNS that meets the life safety criteria.
To influence a building rating, a part, element or SSNS must be of sufficient size and located such that their failure would lead to a significant life safety hazard. This will typically relate to their ability to continue to support gravity loads (including their own weight).
Under the old system, there was overlap between the requirements of the earthquake-prone building legislation and the obligations owed under health and safety legislation. In response to this, WorkSafe issued a Position Statement. This is not binding on WorkSafe but lays out its intended enforcement approach.
WorkSafe states that it will not take health and safety action against you in relation to the earthquake resilience of your building because this is covered by the Building Act and enforcement is the responsibility of your local council. But it then goes on to say that if, after an earthquake-related serious harm incident, it becomes clear that you failed to comply with the Building Act, you could face enforcement action under the HSWA for failing to take all practicable steps to ensure the safety of employees and other people in or near the building.
We take this to refer to a situation where earthquake strengthening has not been carried out within the timeframes required under the Building Act. It would be good if WorkSafe clarified this point.
WorkSafe also draws a distinction between hazards covered by the Building Act and hazards attached to building components or other chattels, fixtures, fittings and equipment in or around a building. WorkSafe expects you to identify and manage these hazards so far as is reasonably practicable, as you would any other workplace hazard. Failure to do so is a breach of the HSWA:
Regardless of whether you’re a building occupier or a building owner, you need to take practicable steps to identify and manage any parts of buildings which could cause serious harm to occupants in case of an earthquake, and to take practicable steps to eliminate them; or if that’s not practicable, to isolate them from people; or if that’s not practicable to minimise the hazard.
Owners and employers need to continually analyse any risks in respect of each building they own or occupy to determine what practicable steps can be taken to manage hazards. What is practicable in any given case will depend on the circumstances. However, in undertaking such analyses, you will need to consider matters such as the extent of the risk; the nature, severity and probability of any injury or harm that may occur; the practicality of eliminating, isolating, or minimising the hazard; and the availability and cost of safeguards. If you’re an employer and you have a concern about a building component which you cannot deal with, you will need to involve the building owner. If you’re a building owner and a problem has been raised about a building component, then you will need to take all reasonably practicable steps to manage the hazard.
WorkSafe defines building components as things attached to the building which could be, but are not necessarily part of, the structural integrity of the building. It cites as examples ceilings, verandas, or glass which could fall out and break. We question whether this distinction is still applicable given these components now come within the new regime.
It may reflect the fact that WorkSafe has yet to update its Position Statement to accommodate the broader ambit of the new earthquake prone building regime. We understand that it is due for review in November.
Gaps in the new system which create H&S liability risk
Responsibility for identifying potentially earthquake-prone buildings sits with the territorial authorities (TAs). But:
- the identification methodology they use is almost exclusively directed at the primary structure
- only if the building falls within one of the three "profile categories" – unreinforced masonry buildings, pre-1976 buildings above three storeys or 12 metres in height and pre-1935 buildings – will an ISA or DSA be required, and only then will SSNS be considered (except if there is significant original unreinforced masonry), and
- buildings which have previously been assessed as over 34% NBS may not be reassessed, meaning that existing SSNS risks may not be uncovered, because assessment of SSNS was not required under the old engineering methodology.
Why you should be concerned
This issue is potentially significant, because it is now recognised that there has been a limited and variable degree of compliance with standards for building services.
These were generally designed after the primary structure, often during the construction phase, and with little consideration for how the building in which they were installed could influence their behaviour during an earthquake. Many existing SSNS elements were proprietary systems and their design and construction were unlikely to have been overseen by a structural engineer.
While this issue was evident following the Christchurch earthquakes, it has only recently started to receive wider public attention. Although few fatalities were solely attributed to SSNS failures in non-residential buildings during the Christchurch earthquakes, they were responsible for the majority of injuries caused directly by earthquake damage. The Guidelines state that engineering assessments should always assume non-compliance with the relevant standards until proven otherwise.
It remains to be seen if WorkSafe will continue to draw a distinction between the primary structure and other parts of buildings. If they do, it would be a policy shift from the position taken under the new regime. In the meantime, owners and employers need to take care in how they interpret and rely on the WorkSafe Position Statement in relation to parts of buildings.
What you should be thinking about
Owners and employers need to engage to ensure that they are both meeting their respective health and safety obligations in relation to SSNS or risk prosecution under the HSWA if someone is seriously harmed following an earthquake.
In practice, we can see that there will be many situations where it will be difficult to determine who carried out the works, and who is responsible to carry out an assessment or seismic upgrade.
In such cases building owners and occupiers may have to share responsibility. Both may be subject to a HSWA duty regardless of who carried out the works.