And he said the Sarjeant Gallery could be one of the key city buildings directly in the path of the policy.
"Our problem is that there just isn't the money - either public or private - to fund the sort of work required to the number of buildings affected. There is simply no money to do what's required," he said.
Mr Laws said the one point of difference Wanganui had over most other centres was its heritage buildings and, for that reason, the policy had to be resisted "every step of the way".
He said council colleagues generally agreed that there had been an over-reaction to concerns about building safety in the wake of the Christchurch earthquakes and now "the Government is showing a similar hysterical over-reaction".
"Three times as many people die on roads every year as have died in the Christchurch earthquakes but no one is suggesting we ban motor vehicles."
He said the impact of what government was promoting would make issues like the parole of Stewart Murray Wilson to Wanganui and the fight to retain maternity services at Wanganui Hospital "look like mere foothills by comparison".
Steve Waters, commercial sales agent with LJ Hooker, said the debate around earthquake soundness of buildings was creating a negative reaction.
"Some of the buildings in our central business district we know don't have very good ratings but, despite that, there are buyers not worrying about that and just prepared to get on with it," Mr Waters said.
He said while the initial reaction in the wake of the Christchurch quakes had settled down, getting insurance cover for those buildings remained a major headache.
"A lot of insurers don't want a bar of these older buildings and that's forcing the owners to go offshore for their insurance cover. The problem with that is they're being forced to pay much higher premiums and that, in turn, is loaded on to the rents their tenants are paying," he said.
Mr Waters said the heritage designation on a number of Wanganui's inner-city properties made them unattractive to some potential buyers for just those reasons.
"It's not as simple as a buyer saying they will knock the building down. You're just not allowed to do that."
But he believed the city had an ideal opportunity to take a much broader look at the city, its buildings and its future direction.
"Salvaging older buildings in some cases is just going to prove too costly. And that means they just stay empty."
In its District Plan review of the city's built heritage, the council said the CBD had a considerable concentration of heritage buildings. But these were at high risk from damage or loss from earthquake, as the bulk are unreinforced masonry or poorly reinforced concrete.
At the same time, it acknowledged heritage buildings were significant for their contribution to the economic success of the CBD, and losing them could see the CBD lose its appeal as a commercial focus and as a tourist destination.
THE PROPOSAL
All non-residential and multi-unit, multi-storey residential buildings be seismically assessed within five years of the changes taking effect, with the information as to whether a building is above or below the earthquake-prone building threshold to be made publicly available on a register.
All earthquake-prone buildings be strengthened, or demolished, within 15 years of the changes taking effect (up to five years for local authorities to complete seismic capacity assessments, followed by 10 years for owners to strengthen or demolish buildings), compared with an estimated 28 years (on average) under the current system.
