St Patrick's Basilica complex committee chairman Sean Toomey and Historic Iona Church Restoration Trust trustee Lincoln Coe said their best advice for people considering upgrading was to get the the right professionals involved.
They also said such projects took time, as there was a long process to go through, and people should not panic, as work could be done in stages.
Their respective projects had started long before the Christchurch earthquakes and they were only just nearly ready to go now, having engaged professionals long ago and raised enough money to start the initial stages of the work.
They also said people should expect new challenges as local authorities required owners to bring buildings up to code for earthquake resistance, and more people tried to access the same small pool of charitable funds and appropriately skilled engineers.
While it cost - the church had paid several hundred thousand dollars for that work - it avoided considerable pitfalls and saved costs and time. Also, many charitable funds would not accept grant applications without that work having been done.
The church had raised about $800,000 of the $2.6 million it needed to upgrade the site totally, including about $300,000 in earthquake strengthening on the South Dunedin Basilica.
"We quite lucky we don't have great spires and towers to deal with."
He said the project was driven by the importance of the site and building, and the passion of the parish to save it and to adapt to the community and church's modern needs.
"Its been the centre of the Catholic Church in South Dunedin for 130 years ... we're trying to put life back on that site."
The church was nearly ready to apply for grants and funds, but was being realistic about what challenges that would present in the post-quake environment. It had accepted the work would have to be done in stages over several years, he said.
"It's not easy. You do have to be a little bloody-minded about it."
Like those working to upgrade the 155-year-old Iona Church at Port Chalmers, he hoped that once people saw some work being done on the site, they would feel more keen to contribute financially.
Mr Coe said about $850,000 of the $2.7 million required for Iona Church's extensive upgrade had been raised, from fundraising events, the parish and various grants, and they were nearly ready to start the prioritised work, which included earthquake strengthening the church and spire.
The trust was a community group that was working with the church parish to upgrade the building.
The community was behind the project because the building was so valued by the whole port community, not just the church, he said.
The trust engaged the professionals needed before the Christchurch earthquakes, Mr Coe said.
Having detailed plans had been integral in getting grants, and it could apply for a second round of funding, but only after the work had begun.
It was certainly going to be challenging to raise more funds, with the likelihood that many people would now be going for the same money pots, he said.
To organisations or groups considering what to do with their buildings, his advice was that it was not the end of the world, and to take time and get a group behind the project.
With some hard work, it could be achieved, he said.
Tony Purvis, who is doing up the Staveley Building in Jetty St for apartments, said earthquake strengthening work there involved tying walls to floors and the roof, and it had been relatively simple to do while doing other work on the site.
He had received much helpful advice from experts in heritage building restoration, he said.
New Zealand Society of Earthquake Engineering executive Win Clark is to give a public talk at the Otago Museum today about how best to protect heritage buildings.
At other, similar, talks around the country, he has outlined how strengthening buildings is not necessarily onerous or particularly expensive.
