One expert claims fixing “poorly done” home repairs arising from the Christchurch earthquake could cost $1 billion.

In an article by Newstalk ZB, structural engineer John Scarry said he is yet to see a competent repair in 140 Christchurch repair jobs he has assessed. He reportedly said repairs done by the Earthquake Commission (EQC) and other insurers were cosmetic.

Scarry lives in Auckland but has reportedly given advice to homeowners affected by the Christchurch earthquakes. He told the publication that common problems include failure to properly re-level timber floors; loose plasterboard linings which reduce bracing and stiffening of the house; “repointing” repairs of cracked brickwork without checking whether the brick ties had failed; and, in one instance, a badly cracked double cavity brick house that was “beautifully” plastered over inside and out while the structural cracking within the walls was untouched.

Read more: 'Botched' EQC re-repairs just the tip of the quakeberg, says expert

Newstalk ZB mentioned figures reported by NZ Herald, which reveal that EQC has spent $315 million on re-repairs with another $322 million forecast for future work, excluding settling court cases.

Now, Scarry said he expects the cost to top $1 billion. He noted EQC had done emergency repairs well, such as taking down damaged chimneys, but he described substantial repairs as “almost always poor.” Repair work was often difficult but had to be done well or not at all, Scarry added.