In what could set a precedent a court has ruled earthquake-damaged foundations of a home with a "when new" insurance policy can be "jacked and packed" instead of being replaced.

The Fitzgerald Family Trust launched court action to compel insurer IAG to rebuild the foundations of a 1920s double-storey weatherboard house in the Christchurch suburb of St Albans.

IAG's plan was to inject the unreinforced perimeter foundation with epoxy resin then replaster it, and re-level the house by "jacking and packing" its timber piles.  The case was heard in Christchurch during October.

The judgment could set a precedent as other Canterbury homeowners with so-called rubble foundations – made of stones and rubble cemented together – have claims before the courts. It could still be challenged by appeal.

The Fitzgeralds had submitted the earthquakes had affected the foundation's ability to support the house, and it had settled into the TC3 ground and exacerbated existing cracking. They provided expert reports recommending the foundations be rebuilt. 

IAG's experts said their repair strategy would be adequate, and met the latest Ministry of Building, Innovation and Employment (MBIE) guidelines on repair standards. 

Justice David Gendall agreed with IAG that injecting the foundations with epoxy resin and re-levelling would both support the house and restore its appearance. The plan met the company's policy obligations, the judge said.

"While this would not meet the current standards for a newly built home, I consider that it does meet the 'when new' policy standard required for repairs to houses of this era, as indicated in MBIE's guidance."

If the repairs could not be done to meet the relevant consenting and building code standards, the foundations would need to be replaced instead, the judge said. 

The judge said the Court of Appeal had already recognised a difference between "as new" and "when new" standards, and the Fitzgeralds' policy required restoration to as similar to original condition as possible, but not to modern standards.

Standards when the house was built only required foundations to support vertical loads, not horizontal or lateral loads as might be imposed during earthquakes. 

Both using epoxy resin to fix rubble foundations and jacking and packing (packing gaps between piles and bearers to level floors on jacked-up houses) have been controversial repair methods since the Canterbury earthquakes.

Updated MBIE guidelines do not specific a repair system for rubble foundations, but say any repair must provide the support the foundations were built for, and meet the building code.

 - Stuff