Media release - Experts identify reasons for Southland Stadium collapse

The roof of Invercargill’s Stadium Southland collapsed on 18 September 2010 because of substandard building design and construction, Chief Executive of the Department of Building and Housing Katrina Bach announced today.

An independent investigation commissioned by the Department, conducted jointly by Hyland and StructureSmith, found four key factors had contributed to the building’s collapse including:

1. Heavy snowfall
2. Problems with remedial works during construction
3. Construction defects, and
4. Design problems.

The snow on the roof did not exceed the snow loading standard of the time.

The investigators found that when sagging of the Stadium roof was observed during construction, remedial works were carried out (including steel fabrication and welding) but these were not sufficient to ensure the integrity of the stadium.

The deficiency in steel fabrication and welding demonstrates inadequate supervision of the remedial construction work.

If the stadium had been constructed in accordance with the design documents for remedial works and construction Standards of the time, it is unlikely it would have collapsed under the snow, sleet and rain on 18 September 2010.

The Department of Building and Housing has accepted the report findings and recommendation that it provide guidance on the design of roof structures that are subject to snow loading.

The Department is also looking into the practicalities of the recommendation that building owners install snow alarms in long span (over 20 metres) steel structure buildings to warn occupants in case of excessive snow loading.

Katrina Bach said the Department would issue a Practice Advisory to Territorial Authorities to encourage building owners to check long span (over 20 metres) steel structures for any of the defects identified by the investigation.

“As a matter of course, responsible building owners regularly inspect and maintain their building stock and the Practice Advisory will provide additional guidance on what they should be looking for in those inspections.”

Ms Bach said public entities would welcome the guidance from the Department as they owned and maintained many long-term community assets like stadiums, and were accountable to their local communities.

Ms Bach thanked the investigators for conducting a robust and comprehensive investigation using internationally recognised methodologies and tools.

The investigation included a site examination, laboratory testing and 3D computer analysis.

Deputy Chief Executive Building Quality David Kelly this morning briefed the Chief Executive, Mayor and Council of Invercargill City Council and the Chair and Board of the Southland Stadium Trust on the findings, and provided a technical briefing to the media.

Mr Kelly said, as part of its response to the Canterbury earthquakes, the Department was implementing changes to improve design, construction and quality assurance processes with improvements to clarity of the Building Code, training, workshops, risk based consenting and Design Features Reports when they are introduced.

“We’re working with industry to highlight the importance of skills, competency and training to ensure all commercial buildings are built right first time,” he said.

The Department has referred the investigation report to the NZ Police and the Department of Labour, and provided a copy to IPENZ – the body responsible for monitoring the competence of engineers.

View the final reports »