The Department of Building and Housing has acknowledged the rules related to earthquake-prone buildings may not be working.
The department faced a grilling in front of the Royal Commission on the Canterbury Earthquakes on Wednesday.
The latest phase of the hearings is focussing on why unreinforced masonry buildings collapsed during the quake on 22 February, killing 40 people.
Current rules, passed in 2004, require buildings to be above 33% of the modern building standard but encourage councils to push for them to reach 67% of the standard as part of best practice.
Under cross examination, Department of Building and Housing deputy head of sector policy Suzanne Townsend was pushed on why nothing had been done since the introduction of the rules to require councils to bring buildings up to the new code.
Ms Townsend admitted it took the Canterbury Earthquakes to prompt her department to look at the extent to which councils and building owners are moving to earthquake strengthen buildings.
She says her department will await the outcome of the Royal Commission before completing its own review of the legislation and deciding whether tighter standards are required.
