The Insurance Council of New Zealand (ICNZ) has taken Christchurch City Council to the NZ High Court for a judicial review of the authority’s powers to increase regulations on strengthening buildings.

Insurers could face higher repair bills under the move to require seismic strengthening of existing buildings to 67% of the requirement for new buildings, up from 33%.

ICNZ has also rejected claims insurers are seeking to delay or avoid payments to Christchurch property owners, saying delays mean inflation and raised building costs.

As the second anniversary of the February 22 earthquake approaches, ICNZ says claims could never have been settled within two years.

It says there are 20,000 properties requiring more than $NZ100,000 ($80,000) of repairs and several insurers plan to complete the work by December 2015.