Rules on damaged TC3 sites delayed

From THE PRESS by MICHAEL WRIGHT  12/03/2012   Source

Foundation guidelines for earthquake-damaged green-blue Canterbury properties will not be ready until mid-April.

The Department of Building and Housing (DBH) is developing foundation designs for quake-damaged houses classified technical category 3 (TC3) by the Canterbury Earthquake Recovery Authority (Cera). The guidelines had been scheduled to be released last month.

The 28,000 TC3, or green-blue, properties are considered to be on the most badly quake-damaged land able to be economically repaired. Houses in the zone needing to be rebuilt or have foundation repairs must meet new foundation standards.

DBH building quality deputy chief executive David Kelly said developing the new techniques had been "more complex than anticipated".

"As soon as you get into work like this, which is new work, there are things you don't know about simply because you can't anticipate it. It's the nature of the work really," he said.

Foundation designs would fall into two broad categories – stabilising the land and "deep piling and making sure the connection to the foundation is properly thought through".

Geotechnical and structural engineers were taking advice from international experts to ensure the new standards were robust, Kelly said.

"We really appreciate that people are anxious to see this work because they want to get on with life, but the worst thing we can do is get it out and be inaccurate," he said. "There is certainly pressure on us to move as quickly as we can, and we are trying to."

Foundation designs that involve land remediation will be new ground for insurance companies as they do not insure land as part of house policies.

AMI Insurance earthquake recovery executive manager Peter Rose said the company had no problem with the designs involving land remediation.

"We believe we have responsibility for any necessary strengthening in the land as it relates to the appropriateness of the foundations," he said.

IAG Canterbury recovery executive manager Dean MacGregor said the insurer took a similar position, but "only at a philosophical level".

"We would definitely consider it on the basis that if it wasn't going to cost any more than we would have paid for those foundations anyway."

The Earthquake Commission is due to start its geotechnical assessments on more than 8000 TC3 properties with foundation damage soon.

Customer services general manager Bruce Emson said delays from DBH would not affect the process. It was already possible to repair some TC3 properties with foundation damage.