A list of 4300 Auckland buildings that could tumble and kill in a moderate earthquake will be kept secret from the public, at least until building owners have had the chance to challenge an engineering assessment of their properties.

The Auckland Council is making it difficult for the public to learn which buildings could collapse, despite a warning from acting building control manager Bob De Leur that many were “held together by gravity rather than mortar”.

The unreinforced masonry buildings in Auckland are of the same type as those that caused “catastrophic damage” during the Christchurch earthquakes, he told the governing body yesterday.

But Mr De Leur, with the backing of Mayor Len Brown and most councillors, believes publishing the list of Auckland buildings could generate unreasonable panic or blacklisting of properties.

Mr De Leur was annoyed that calls for the list to be released were based on “sensationalism” and came before buildings owners had time to challenge council and engineering assessments.

Building owners have been given four months to object, but Mr De Leur made no promise to go public with the list once the deadline is up and the council has a more accurate picture of the number of earthquake-prone buildings.

It was one option, he said.

He said the final assessments would be placed on property files, which are available to the public on request at a cost of between $155 and $345.

The Wellington City Council publishes a list of 205 earthquake prone buildings which can be viewed online at no cost.

The list, in alphabetical order by street, contains the name and address of each building, a brief description of the type of building and whether it has Historic Places Trust or council heritage status.

Sharon Stewart was the only councillor to express concern about the list not being available to the public.

“It would be on our heads as councillors if we do know there are buildings out there that are prone to earthquakes and we don’t provide a list,” she said.

During a discussion on the draft earthquake-prone building policy – required under the Building Act 2004 – Mr De Leur said the initial assessments could be affected by things such as soil type.

Earthquake-prone buildings are defined under the Building Act as likely to collapse causing injury or death in a moderate earthquakes.

After the Canterbury quakes, the Institute of Geological and Nuclear Sciences confirmed a 2006 study it undertook which found that Auckland was an area of low seismic risk.

Mr Brown said the city was at greater risk from tsunamis and volcanos.

Councillors have made a change to the draft policy to extend the time for strengthening heritage buildings from 20 years to 30 years.

BUILDING WATCH

* Auckland Council will keep hidden the 4300 buildings that could collapse in an earthquake.

* Owners have four months to challenge the council and engineering assessments.

* Assessments would be placed on property files which the public could pay to access.

* Wellington City Council publishes a list of 205 earthquake prone buildings online at no cost.

– By Bernard Orsman, nzherald.co.nz