UPDATED 9:37am: The New Zealand Society for Earthquake Engineering is backing the government's change to earthquake strengthening requirements.

Building Minister Nick Smith wants to divide the country into low, medium and high risk areas, decreasing the number of buildings needing assessment from $500,000 to $30,000.

The measures will reduce the number of buildings needing assessment by prioritising hospitals and schools, but demolishing some heritage buildings.

President Dr Quincy Ma told Newstalk ZB the changes are well considered and practical.

"It strikes a balance between insuring minimum safety education affordability and practicality.

"It comes down to economics. We can't put the country into bankruptcy just to prevent for a hazard that may not occur in the meantime."

The body representing property investors is welcoming the Government's overhaul of earthquake strengthening rules.

It will significantly reduce the number of buildings needing strengthening, and ease the deadlines for strengthening in lower-risk areas.

Property Council chief Connal Townsend says public safety should always be at the forefront of any rules.

But he says businesses can't afford the extremely high costs associated with strengthening.

The leader of the Opposition is pleased not every building will be treated the same when it comes to earthquake strengthening.

Andrew Little says the original proposal was too crude, and required greater sophistication.

He says it's good to see the Government has responded to the pressure every MP has been under.

"For a more tailored approach to making sure that buildings are safe and fit for habitating in the face of a risk of earthquakes."

Opposition to the changes

There is some opposition to the proposed change to earthquake strengthening requirements.

The Government is being accused of going too far with its proposed loosening of earthquake strengthening rules.

Housing Minister Nick Smith says the current rules are arbitrary, because no one was killed in the Christchurch quakes in a building meeting 34 percent of new building standards.

Structural engineer John Scarry told Newstalk ZB that simply isn't true.

"The CTV building and the PGC building were rated well above 34 percent new building standards, and they killed 133 people."

The move to change policies around earthquake strengthening, has raised a few questions at Wellington City Council.

Councillor Iona Pannett says while agreeing there's a need for change, she's concerned as to why monuments and tunnels will no longer require strengthening.

She's concerned these have been left off the list, considering how seismically active Wellington is.

"I think we'll have to have some further discussion with the Government about exactly what they're thinking is, because for example if the Mount Victoria tunnel was ever too collapse that would obviously be catastrophic.

"There's absolutely no discussion of how all this work will actually be paid for. Obviously strengthening buildings costs us a lot of money. Building owners in Wellington have huge costs, and they can't necessarily afford them."

Heritage buildings

The new approach to earthquake prone buildings could take the pressure off some heritage building owners.

Hospitals and schools will now be prioritised in high risk areas like Christchurch and Wellington.

The changes will also reduce the number of buildings requiring inspection across the country, and increased time frames.

Structural engineer John Scarry points out some heritage building owners who were worried about costs could now take a graded approach.

"Even if you don't get around to upgrading these old masonry buildings, what you could do is get an immediate bang for the buck, putting in posts to support the canopies. [That] would be removing a major danger." 

Labour leader Andrew Little is welcoming a more targeted approach to how buildings are assessed, but he says it would be very disappointing if the changes meant the loss of a lot of heritage buildings.

He believes the Government could stump up, and perhaps contribute to community efforts to preserve important structures.

"I'd like to think there's scope to do that, rather than if they don't make the grade they get knocked down."

Little acknowledges there may be greater expense in making sure heritage buildings are saved, but they represent a beauty not often seen in architecture today.