Palmerston North's historic All Saints Church is closing to the public because of fears around its structural integrity.

The 100-year-old building was rated as being at just 3 per cent of the building code this year by the Palmerston North City Council, as part of a city-wide investigation into the strength of buildings.

Buildings must reach at least 34 per cent of the safety standard to avoid being classed as earthquake-prone.

Yesterday afternoon, vicar John Marquet announced the building would be closed to the public from April 1, 2013.

The community hall at the back of the church would remain open.

One of Palmerston North's most recognisable buildings, All Saints is also a popular venue for weddings and funerals, with its traditional church ambience.

The decision to close the main building was made after the parish sought legal advice around its liability for safety in the event of an earthquake, Mr Marquet said.

Other churches around the country were also closing after seeking legal advice, depending on how much of the building code they reached.

Mr Marquet said churches which slipped under 15 per cent were closing, so the decision was not difficult for the parish to put to the congregation.

A decision regarding whether the church would be demolished or repaired had not been made yet, but something had to be done in the meantime, he said.

Quotes from 18 months ago put the cost of strengthening the church at about $2.2 million, he said.

"That's before consultants' fees and assessment costs - we're talking $3m or $4m all up.

"For the congregation that would mean a huge amount of fundraising to strengthen the building."

A vote taken at a special meeting of the church had about 90 per cent of the congregation agree the church had to be shut, Mr Marquet said.

"There is a lot of sadness, and some are still challenging parts of it, calling it political correctness gone mad."

Having the church open until after Easter would enable people to say their final goodbyes, he said.

"We will be trying to open the building each day in December for people in the community who want to have a look around."

Palmerston North Mayor Jono Naylor said the council has a heritage fund that it has used to help with the cost of projects at All Saints in the past.

But the fund would "barely make a dent" in the likely cost of the strengthening work needed at the church, he said.

While he respected the church's decision, Mr Naylor said New Zealand would be unable to cope if owners of earthquake-prone buildings nationwide took the same approach.

All Saints Church is both a category one heritage building with the Historic Places Trust and in the Palmerston North District Plan.