ANZ yesterday announced it would offer a "Healthy Home Loan Package" across New Zealand, for customers wanting to build or upgrade homes to improved standards.
The deal included a 0.7% discount off the standard fixed home loan rate, 1% off the standard floating and flexible home loan rates, and fee waivers, the bank said.
They would be available for homes which rated a six or higher on Homestar, an independent tool used to rate the health, warmth and efficiency of New Zealand homes.
Mr Cull said he was not aware of the initiative before yesterday's announcement, but he thought it would help encourage healthy homes in Dunedin as well as other parts of the country.
"I thought it was a really great initiative.
"Not only is the standard of a lot of existing homes in Dunedin pretty poor, but actually our new building standard is really just the worst standard you're allowed to build to - that's the building code.
"Really, we need to be lifting the bar."
Dunedin's Cosy Homes Trust, established in 2015 to help tackle health and housing-related problems in Dunedin, had been exploring ways to build partnerships and collaborations with other organisations to advance its goals, he said.
There was no formal relationship between the trust and ANZ, but the bank's initiative would add to the "suite" of advice the trust could offer people seeking advice on financing their home improvement projects.
It was also encouraging to see a commercial entity agree with Cosy Homes' thinking, he said.
"I think corporates in general are looking at their social responsibilities and they're canny enough to know that they will appeal to a bigger and bigger range of people who are increasingly conscious of these issues."
ANZ New Zealand retail and business banking managing director Antonia Watson said most existing homes scored only a two or three out of 10 on the Homestar rating system.
Most new homes, even though they were built to current building code requirements, would also only achieve three or four, she said.
The New Zealand Green Building Council had calculated it cost about 1.5% more to build a three-bedroom house which achieved a Homestar score of six, but that home would then cost about $500 less a year to run.