Building owners in high-risk earthquake areas will need to tie back unsecure masonry parapets and facades within the year, the government has announced.

Photo: Flickr / Wellington City Council

The government said last year's Kaikōura earthquake had significantly increased the seismic risks in Wellington, Lower Hutt and Blenheim.

It is using its emergency powers under the Hurunui/Kaikōura Earthquakes Recovery Act to require building owners in those areas to secure facades and parapets within 12 months.

Up to half of the costs to do the work will be met by local councils and the government, which has established a $3 million fund to help pay for the work.

Building and Construction Minister Nick Smith said about 300 buildings had been identified as high-risk. The tie-back work would cost about $20,000-$30,000 each time, but significantly reduce the risk of fatalities in an earthquake, he said.

"The Kaikōura Earthquake has significantly increased the seismic risks in Wellington, Lower Hutt and Blenheim during the next three years. The prudent response is to require and to assist building owners of these high-risk, unreinforced masonry parapets and facades to secure them urgently.

"Falling unreinforced masonry facades and parapets pose a major risk to people on the street during an earthquake. We saw the terrible harm that can be done when 39 people were killed by unreinforced masonry in the 2011 Canterbury earthquake."

Dr Smith said the government would also use the special law to exempt the required work from requirements to gain resource and building consents, provided the work was overseen by a qualified engineer.

"The powers will rest with the council to actually just get on and do the work and to bill the property owner. Furthermore, there is the power under the Building Act for a fine of up to $200,000 in the event that any one of those 300 building owners ignore this new legal requirement we're putting in place."

'Heightened period of risk'

A summary of recommendations from the New Zealand Society for Earthquake Engineering, prepared for the minister in December, said commercial and retail areas such as Riddiford Street and Cuba Street in Wellington, and Jackson Street in Petone, were of greatest concern.

The society's president, Peter Smith, said the aim was not to frighten people but to make sure the right measures were taken.

"We're not trying to scaremonger in terms of the risk that is out there, but there is a heightened period of risk and that heightened period of risk has the potential for causing loss of life and we think that's appropriate to take these measures."

Mr Smith said, as well as the 39 people killed, 100 people were injured in the 2011 Canterbury earthquake because of unsecure masonry.

Justin Lester, the mayor of Wellington, where 250 of the 300 high-risk buildings were located, said the move was a sensible precaution.

"We've said consistently here in Wellington that we want to make sure the city is safe ... Public safety has been out paramount concern since we had the earthquake in November of last year."

The regulations were to be put in place by the end of February, with affected buildings to be notified in March.