SDC reviewing building policy

Friday, 3 December 2010

The Southland District Council is proposing to amend its earthquake-prone building policy to mitigate future risk following the devastation of the Christchurch earthquake.

Council has approved a proposed Earthquake-prone and Dangerous/Insanitary Building Policy options for public consultation and is calling for public submissions. The submission period openend on Wednesday and closes on 28 January, 2011. The proposed policy can be viewed at www.southlanddc.govt.nz.

Building Control Manager Kevin O'Connor said the policy must be reviewed within five years of its original adoption and in place by March 2011.

"The damage to unreinforced masonry buildings in both the 2007 Gisborne earthquake and more recently in Christchurch was certainly a timely reminder for us all," he said.

"The council's existing earthquake-prone building policy takes a passive approach to structural upgrade in line with minimum requirements of the Building Act.

"Given there are approximately 200 buildings which have the potential to fall within the definition of an earthquake-prone building in the Southland District Council's area, we need to be promoting a more active approach."

Whilst the proposed amended policy may result in an economic impact to the owners of at-risk buildings in either strengthening or mitigating the hazard, statistics showed comparisons relating to seismicity could be drawn.

"Some areas in Southland, including Te Anau, Milford, Riverton and Winton, have comparable and even greater seismic risk that Canterbury or Gisborne," Mr O'Connor said.

"It reinforces the need to take a more active stance in regard to earthquake strengthening and the level of strengthening."

The introduction of timeframes for earthquake strengthening of identified buildings was the major change to the amended policy.

Buildings identified as potentially earthquake prone in the lower risk/least importance category will have 30 years to take action to strengthen or remove the hazard by demolition while those deemed the highest risk/most important will have 15 years. There is provision for extension of up to three years if substantial progress has been made by the owner.

The amended policy also recommends building consent applications for significant alterations to buildings identifies as potentially earthquake prone must be accompanied with a structural assessment. Where a building's strength is determined as 33 percent or less of current requirements, strengthening to at least 67 percent of the code will be required as part of the alteration work.

Mr O'Connor said estimates showed that increasing the strengthening requirement from 33 to 67 percent increases costs by approximately 10-15 percent whilst significantly increasing the buildings earthquake stability.

"However, there is potential for indirect economic benefits to the wider community in that there would be significantly less disruption and potential damage to at-risk buildings in the event of an earthquake," he said.

"You just have to look at the damage suffered in the central business areas of Christchurch to realise how devastating it can be. A relatively small additional cost can raise the standard of public safety significantly in such buildings.

"We also need to consider the risk to life from these buildings."

Since the magnitude 7.1 earthquake struck in September, the Christchurch City Council has also reviewed its earthquake-prone building policy to increase the minimum strengthening requirement from 34 percent to 67 percent.

Council staff planned to undertake a review of the Southland District's building stocks from July 2011 to determine potentially earthquake-prone buildings before the proposed alteration and timeframe provisions are introduced in July 2012.

To make a submission and to see the document in full, please follow the link: http://southlanddc.govt.nz/consulting

Who to contact

If you would like to discuss a matter on this page, feel free to contact us:

Southland District Council
P.O. Box 903
Invercargill 9840
Phone: 0800 732 732
Fax: 0800 732 329
emailsdc@southlanddc.govt.nz