Fears foundations will not be fixed

Government guidelines for fixing quake-damaged homes have been changed, meaning some cracked or tilted foundations will no longer be fixed.

The Department of Building and Housing released its guidelines for rebuilding quake-damaged homes within two months of the September 2010 earthquake but revised them in November last year.

The new guidelines advise assessors or builders working for insurers or the Earthquake Commission (EQC) to tolerate larger cracks and a greater slope in foundations before recommending repairs.

Some building industry sources have expressed concern about the changes, claiming they could leave homes with quake damage while saving the Government and insurers money.

One Canterbury builder said relaxing standards and the push to speed up repairs meant the city would face a problem similar to the leaky homes saga in 10 to 15 years, with many homeowners eventually discovering hidden quake damage.

Other builders said the changes were sensible, giving leeway for damage that may not have been caused by the quakes or would have little impact on the home.

Colin Gray, of C&LA Gray Builders, said he was comfortable with some of the revised guidelines but not the part that specified that cracks of up to 5 millimetres in a concrete slab do not require fixing.

"Every home we do we are repairing all the cracks. I can't see why you wouldn't want to repair the cracks."

Another Canterbury builder, Carl Taylor, said it was not uncommon for foundations to have a slight slope before the quakes, often the result of shoddy building.

"I think they [the guidelines] are acceptable but if there is a crack, we are fixing it, regardless of the guidelines."

The department's chief engineer, Mike Stannard, said the revised guidelines would not lead to any loss of amenity for homeowners and were more "realistic" than those drawn up hastily after 2010 September quake.

"It is now more realistic in identifying earthquake damage," he said.

After the September quake, there had been complaints the department's guidelines had led to otherwise undamaged homes being written off because of slight damage to their foundations.

"They were being applied a bit prescriptively without proper consideration to the rest of the house. The guidelines were not meant to be hard and fast."

Stannard said cost-saving was not a factor in revising the guidelines. It was a "sensible technical decision", but it could save insurers and the EQC money.

The changes were supported by both international research and the department's own tests, which showed anything less than 10mm was indiscernible to the occupants.

While some rules had been relaxed, other had been tightened, such as introducing a 50mm limit across the entire footprint of the building, he said.