Checks have been made on the quality of the earthquake design of several buildings in Christchurch, but Wellington has been unable to follow suit.
This follows design defects by structural engineering company Kevin O'Connor and Associates (KOA) being identified in relatively new buildings in Palmerston North and Masterton.
The Christchurch City Council said it had identified 15 buildings primarily designed by KOA.
"An initial check of the files did not raise any concerns," the council said.
"As the designs are considered relatively low risk by the type of structural element or the use of the building, none of these designs require a more detailed investigation."
But the Wellington City Council has not identified any buildings because its computer system can't manage it.
"The council teamwork document system, in which Building and Resource consents and associated information are stored, does not enable searching on a name to bring up consents that are associated with the name," the council told RNZ.
"Searching on 'Kevin O'Connor Associates' and derivatives of the name produced a list of over 11,000 records ... without assessing each individual record we are unable to narrow the results of the search down."
Even for buildings that were on the national earthquake-prone buildings (EPB) register, the engineer who designed them was not identified, it said.
Neither council had any inquiries underway or had received any communications about KOA buildings.
Neither council had looked at the matter before, even though KOA had offices in both cities, and despite the concerns in Masterton and Palmerston North beginning in 2016, that triggered inquiries in both of those places.
The latter city has almost 150 KOA-designed buildings, but the city council has looked at only a dozen of them, finding eight had substandard designs, five to the extent they have now been classified earthquake-prone, the worst classification.
The council had consented these designs.
In Wellington, the city council said it was "confident that the building consent review process that we have in place ensures that if buildings are built in accordance with the approved building consent they would comply with the building code".
The Auckland Council has delayed its response to RNZ's request.
KOA had offices in all three cities but appears to be inactive.
Its directors and shareholders are now connected with a company set up in 2018.