Changes to the Earthquake Strengthening Policy
Dr Nick Smith, the Minister for Building and Housing, announced the government’s proposals to change the timeframes for assessing and strengthening earthquake prone buildings.
What it means to us..............
Building and Housing Minister Dr Nick Smith says the changes will reduce the number of buildings that would require assessment from an estimated 500,000 to 30,000, and bring down the total estimated cost from $1,360 million to $777 million. Currently buildings that could be a risk need to be assessed within five years, with any strengthening carried out within 15 years.
The country will now be split into 3 zones according to the risk of a big earthquake, and the timeframes for assessment and strengthening vary accordingly i.e.:
• High Risk Zone – including Gisborne, Napier/Hastings, Palmerston North, Wellington, Blenheim, and Christchurch (will keep the existing timeframe of assessment within five years and strengthening within 15 years).
• Medium Risk Zone – including Hamilton, Tauranga, Rotorua, New Plymouth, Wanganui, Nelson, Invercargill and Timaru.
• Low Risk Zone – including Northland, Auckland, Oamaru and Dunedin.
The Government has also confirmed that the earthquake-prone building definition as being less than 34% of the new building standard, a 10-year extension for listed heritage buildings, and exemptions from strengthening for low risk, low occupancy buildings, would remain in the policy.
As Hamilton has been classed as ‘medium risk’, buildings will have 10 years to be assessed and 25 years to be strengthened under the proposed policy. Many of Hamilton’s buildings have already been assessed by engineers and it is unlikely they will be subject to any further assessment.
The return period for a significant earthquake (MM8) ranges from 120 years in Wellington, to 720 years in Christchurch, to 1700 years in Dunedin, and only once every 7,400 years in Auckland. Education and emergency buildings (e.g. hospitals) will be targeted by requiring that in high and medium seismic risk areas they be identified and strengthened in half the standard time.