BRANZ: Decision-making framework for earthquake-prone council buildings

BRANZ has co-designed a framework to help territorial authorities confidently and robustly make decisions on managing earthquake-prone council buildings that are in the best interests of their communities.

Since the Kaikōura and Christchurch earthquakes, new legislation has led to many earthquake-prone buildings sitting empty, resulting in community facilities and services being suspended. In response to the Building (Earthquake-prone Buildings) Amendment Act 2016 and the introduction of the new building standard (NBS) as a metric for seismic performance, some territorial authorities have since rapidly closed buildings with NBS ratings of less than 34%, pending their remediation or demolition.

When public buildings close, communities go without spaces to meet, socialise and access services, sometimes leading to negative impacts on social and economic wellbeing. Without clear, documented policy on building closure that considers all the risk factors, it is difficult for decision makers to explain the rationale and gain community buy-in for their decisions.

BRANZ led a Levy-funded research project, working with collaborators andterritorial authorities,to understand how engineering advice and community impacts translate to public policy decisions about earthquake-prone council buildings.

A series of recorded interviews were conducted with eight staff representing five territorial authorities across New Zealand. Interviewees included property owner and regulatory arms of councils and were from territorial authorities of varying sizes and located within different seismic zones. Interview questions were designed to enable interviewees to talk through their respective decision-making processes, in particular, who makes decisions, what the key decision drivers are and how seismic risk information is assessed alongside other risk information.

Based on interview findings and expertise within our research team, researchers and collaborators developed a ‘strawman’ decision-making framework reflecting a possible best-practice approach to seismic risk management in council buildings that also considers community impacts.

The final five-step framework aligns with the international standard for risk management (ISO 31000), stepping users through the risk identification, assessment, and treatment phases of risk management.

By applying the framework, decision makers can weigh up multiple factors. These include the number of building occupants, the average time spent in the building, and the duration the building will be earthquake-prone, along with the social and economic consequences of closure.

The framework enables councils to balance their legal obligations under the Building Amendment Act in 2016, the Health and Safety at Work Act 2015, and the Local Government Act. The framework is also a useful tool for any building owner needing to make these kinds of decisions.

Working in collaboration

BRANZ acknowledges collaborators Resilient Organisations, Kestrel Group, the University of Canterbury LEAD Institute of Law, Emergencies and Disasters and Massey University Joint Centre for Disaster Research. The contribution of several territorial authorities was also crucial to the development, testing and refinement of the framework.

Download the framework

Further information

BRANZ Research Now: Seismic resilience #2 Managing earthquake-prone council buildings.

BRANZ Study Report SR463 Managing earthquake-prone council buildings: Balancing life safety risks and community costs.

About BRANZ

A multi-faceted, science-led organisation, BRANZ uses independent research, systems knowledge and its broad networks to identify practical solutions that improve New Zealand’s building system performance. BRANZ is driven by the knowledge that to thrive as a society, New Zealanders need a built environment that is safe, healthy, and performs well.

Website link: https://www.branz.co.nz/