LIM notices issued to potentially earthquake-prone buildings

Southland District Council has issued the owners of un-reinforced masonry commercial buildings in the district with Land Information Memorandum (LIM) notices identifying their buildings as potentially earthquake-prone.Council's building control manager Kevin O'Connor said the Department of Building and Housing guidelines and events in Christchurch had influenced Council in taking a more active stance in the five-yearly review of its Earthquake-prone Building Policy. "The major change is the introduction of strengthening timeframes for identified buildings which has been effective since 1 July and ranges from 15 to 30 years depending on the building's use," he said.

A survey was undertaken to identify un-reinforced masonry commercial buildings falling within the definition of potentially earthquake-prone throughout Southland District. "Council wrote to all commercial building owners back in July 2011 advising them of the policy changes. Owners were also informed that a district survey would be undertaken to identify potentially earthquake-prone buildings for recording purposes," Mr O'Connor said.

The minimum level for structural upgrade under Council's policy is 34 percent of the new building standard, with a recommendation that owners of identified buildings consider upgrading to 67 percent for additional life safety, property protection or business continuity purposes. Council is recommending for owners of potentially earthquake-prone buildings to engage a Chartered Professional Engineer (CP-Eng) to carry out an Initial Evaluation Procedure (IEP) assessment of the building to determine its earthquake capacity.

"Un-reinforced masonry buildings typically struggle to meet 34 percent of the new building standard. However, if a building's strength can be confirmed at 34 percent or greater by way of an IEP assessment and reported back to Council, the potentially earthquake-prone status will be removed from the LIM notice," Mr O'Connor said.

The Royal Commission's investigation into building performance in Christchurch may yet bring in legislative change raising the minimum strengthening requirement above the current 34 percent. If that happens, Mr O'Connor said that Council would then need to review its Earthquake-prone Building Policy.
"This would no doubt increase the number of buildings above the approximate 105 already identified through the district survey."