Earthquake risk: Warning hospital buildings could be unusable after big shake

Hutt Hospital's Heretaunga block has been deemed earthquake-prone. Photo / Mark Mitchell

A new report warns many key hospital facilities, such as operating theatres, could be unusable in the immediate aftermath of a major earthquake.

Te Whatu Ora Health New Zealand has published a report into the seismic resilience of hospital buildings across the country.

Non-structural elements of hospital buildings, like pipes for medical gases and steam, fire sprinkler pipes and specialist medical equipment, were raised as a key concern.

There was a lack of information about whether this equipment was adequately restrained or separated, the report said.

This limited the understanding of how resilient hospital buildings were and whether they could function following a significant earthquake.

“However, the likelihood of having key facilities such as operating theatres rendered unusable due to damage to non-structural elements in earthquakes appears quite high for many hospital buildings,” the report found.

Overall there were no assessment records found for more than a third of all hospital buildings, including 40 classified as being of level four importance.

Buildings in this category must be operational immediately after an earthquake or other disastrous event.

Of the buildings which were assessed, 103 had New Building Standard (NBS) ratings below 34 per cent, which is the threshold at which buildings are deemed earthquake-prone.

These accounted for 13 per cent of the overall number assessed.

The report also highlighted concerns about the shortcomings of relatively modern hospital buildings constructed after the year 2000.

“These are buildings that until recently had been thought to represent a low seismic risk, but learnings from the Canterbury and Kaikōura earthquakes have highlighted areas of vulnerability in aspects of modern construction.”

A number of the completed seismic assessments were dated and did not take into account changes to the Building Act, which came into force after these earthquakes, the report said.

It was expected many hospital buildings with low ratings would continue to be used for some years until replacement facilities could be built.

But given a number of buildings may not be useable immediately after a major earthquake, there needed to be a stronger focus on identifying alternative facilities and factoring this into hospital emergency plans, the report said.

Several other recommendations were also made around updating seismic information, developing a seismic policy for Te Whatu Ora and implementing new technical guidelines for designing and assessing hospital buildings.

Te Whatu Ora chief executive Fepulea’i Margie Apa said they would not be complacent.

“Now we can take a national look at the seismic performance of our health infrastructure, we can also formulate a strategy to identify where buildings are not rating as high as we would like and form a management strategy to prioritise and carry out mitigation works where needed.”

A work programme has been stood up to address the report’s recommendations.

A draft seismic policy has already been prepared and will be given to districts and other relevant organisations for consultation before release.

Apa said while a low NBS rating may concern people, recently published guidelines from the Ministry of Business, Innovation and Employment have clarified there was no need for alarm or immediate action.

“The life safety risk is still very low, as the seismic assessments of hospital buildings are extremely robust with the criteria for acute services buildings representing earthquakes only likely to occur once in 2500 years.

“However, ensuring our buildings are safe for Te Whatu Ora staff and patients is always a top priority, and it is important that we do have a policy in place to develop resilient hospital buildings, not only during a seismic event, but in terms of functionality afterwards.”