A billion-dollar earthquake upgrade affecting about one in 10 commercial and multi-storey apartment buildings is set for a major overhaul, after engineering experts rubbished the Government's original plans as unnecessary and unworkable.
Almost 200,000 buildings throughout the country are due to be checked for structural weaknesses in the next five years, with up to 25,000 expected to need expensive strengthening work under the Earthquake-prone Buildings Amendment Bill.
But critics of the bill say it is a huge overreaction to the Christchurch earthquakes and will impose excessive costs on property owners, force the unnecessary closure of many old buildings in areas of low earthquake risk and possibly cost as much as $10 billion.
The country's leading engineering body, the Institution of Professional Engineers, warned a select committee considering the bill that the new regime was likely to cause the destruction of value in many older buildings, which would be unjustifiably listed as earthquake-prone.
"The nation also cannot afford high costs of strengthening that will ultimately offer few public safety benefits."
A working group set up by the main professional engineering bodies suggested:
• Using a more sophisticated test for earthquake risk than the current one-third of the strength of a new building.
• Limiting checks to buildings which are multi-storey or made of unreinforced masonry (mainly old brick-and-mortar or stone buildings).
• Making owners of old brick buildings tie back parapets and chimneys immediately, instead of spending millions on the whole structure.
The legislation has already had a chilling effect on the property market. Landlords and real estate agents have warned that tenants have fled heritage buildings, which have plunged in value. Many owners cannot afford to fix their buildings but are not allowed to demolish them because of heritage concerns.
Building and Construction Minister Nick Smith told the Weekend Herald this week that he had asked officials to come up with a compromise plan that would cut costs, limit work to those buildings that needed it most and still have the legislation ready to be introduced by the end of the year if National was re-elected.
He rejected the engineering group's proposal that earthquake risk should be determined by a new calculation which combined seismic risk, construction standard and the number of people using the building, saying it did not provide enough legal certainty.
But in broad terms he agreed "we've thrown the net too wide" and said his officials were working along the lines of the group's other suggestions.
"Obviously timber-framed buildings that are only one or two storeys pose far less risk than a multi-storey masonry building ... We know that masonry parapets and verandahs were actually areas where there was substantial loss of life [in the Canterbury earthquakes], that the costs of repair are relatively modest and that we can get some of the biggest safety benefits at the least cost."
Dr Smith said he was also considering whether the bill should cover only buildings built before 1977, instead of 1991, the current cut-off date. This change would have to be balanced by a new legal obligation for all engineers to notify the authorities if they knew a building was substandard, to avoid a repeat of the CTV disaster. The CTV Building, which blatantly breached earthquake standards and killed 115 people, was built in 1988.
As well as commercial buildings, the bill will affect heritage apartments, 224 schools - including Auckland Grammar, Diocesan School for Girls and King's College - and many hundreds of churches.