A new deadline of 50 years to strengthen earthquake-prone buildings will preserve Auckland's heritage areas, a trust that owns old buildings says.
Major changes to how quickly earthquake-prone buildings will need to be assessed and strengthened have been announced.
Building and Housing Minister Nick Smith said the changes would reduce the number of buildings that would require assessment from an estimated 500,000 to 30,000.
It would reduce the total estimated cost from $1360 million to $777 million - with $350 million of savings coming from Auckland.
The 15,000 to 25,000 earthquake-prone buildings nationwide that will need upgrading is not expected to change, but the allowable time frame for work in low-risk areas such as Auckland and Northland has been significantly increased - from 20 years to 50 years.
The Government has come under pressure to re-examine its proposed rules around earthquake strengthening after people who own older buildings faced huge bills and uncertainty, and groups using heritage buildings predicted they would need to be abandoned or pulled down.
Glenn Teal, of the Baptist charity Tabernacle Trust, said yesterday's announcement was fantastic news.
The trust owns heritage properties in Karangahape Rd, including one that is 100 years old and would cost $765,000 to strengthen from its 17 per cent earthquake rating to the required 34 per cent.
"What was being proposed would have just been a complete waste. We would have had to knock down buildings for nothing," Mr Teal said.
"That imminent threat of needing to demolish them to comply with earthquake requirements is now pushed out ... That means you can get on and refurbish your old building and keep it in economic life."
The Earthquake-prone Buildings Amendment Bill - expected to be pass this year - will still require every commercial, public or multi-storey residential building to have at least 34 per cent of the earthquake design strength expected of a new building.
Building owners and councils around the country were previously given five years to assess buildings, plus a further 15 years to complete any necessary strengthening.
The country will now be split into zones according to the risk of a big earthquake, and the time frames for assessment and strengthening varied accordingly.
Affected buildings in low-risk areas such as Auckland, Northland and Dunedin will now need to be identified and assessed within 15 years and strengthened within a further 35 years. Heritage buildings can still get a 10-year extension - meaning some buildings may not need strengthening for 60 years.
The time frame will be 10 years and 25 years for buildings in medium risk areas, including Hamilton and Tauranga. High-risk zones such as Wellington and Christchurch will keep the existing time frame of strengthening within 20 years.
Education and emergency buildings in high- and medium-risk areas will need to be upgraded in half the standard time.
Dr Smith said the changes would make savings and retain the same safety gains. The longer time frames would mean much strengthening could coincide with other renovations, saving money.
Labour leader Andrew Little said the previous approach had been crude. Labour wanted to work with the Government to make sure any new legislation was sound, such was its importance.
Auckland Mayor Len Brown welcomed the changes and said they came after submissions from the council and other local authorities.