All but 16 owners of the 1200 properties with the most severe land damage in last month's massive Canterbury quake have been told that their land can be fixed and that they will be able to rebuild on the original site.

But some owners will need to decide whether to spend more money than their insurance payout on repairing the land on their section, if they want to rebuild, and the process may take years.

The Earthquake Commission (EQC) today released a stage 1 report by its geotechnical consultants, Tonkin and Taylor, with assessment of land damage at both broad and local levels, reconstruction standards of repair and replacement, information on land and building reinstatement, and general remediation options.

An EQC loss adjuster and a geotechnical engineer this week visited the 16 home owners in the hardest-hit suburbs whose properties are most affected.

The properties on the land need further investigation to decide whether or not they can be repaired.

The report released today said that where buildings can be repaired on their existing foundations, it is likely that the damage to the buildings is not so severe that they needed to be evacuated, so the land is considered to have complied with building codes.

Even where buildings require demolition because they cannot be repaired within the building's insured value, but they have maintained a sufficient margin of safety against collapse, the land on which they sit has also been judge "code compliant".

"The decision as to whether or not to rebuild on improved foundation systems is therefore a matter for the owners," the report said.

Where major land deformation has occurred - because of liquefaction or ground movement - expensive engineered building foundations or ground protection may be needed to comply with the building code.

In some cases this might require a 1m-thick reinforced concrete raft foundation, and on those sites, it may be more cost effective to increase the ground resistance to movement through compaction.

Tonkin and Taylor assessed more than 16,500 properties in the 17 suburbs which had the most severely affected reported land damage. About 60 per cent of those properties have not experienced any land damage.

" Even if houses are badly damaged and need to be demolished, all but a handful of Cantabrians will be able to re-build on their original site once the land is repaired," the EQC said.

But delivery of individual remediation plans for properties will take some time, and will have to be coordinated with suburb-wide work on infrastructure such as sewage networks.

"Our best estimate is that the actual process of repairing land and rebuilding houses affected by the quake will take up to two years," EQC said.

"If you are insured, then EQC will pay for the reinstatement of the land and the first $100,000 of building damage and your private insurer, depending on your policy, will pay for the rest of the building damage".

Because land remediation involves specialised expertise and large-scale co-ordination between EQC, private insurers, councils and homeowners "it is unlikely any physical remediation work will get underway before early in the New Year".

- NZPA