ACC says an extra 338 two-bedroom houses, 2 million metres of scaffolding and and 1 million metres of roofing could have been built in the past five years, if it was not for preventable injuries among tradespeople.
It is putting $3.9 million into changing the construction industry's track record, as data reveals more than 100 new injury claims being lodged by tradies each day.
Among those who have contributed to the tally is Ben Clisby, who works as a roofer in the lower North Island alongside his three half brothers and his father.
He said working in a physical industry on a sloping surface meant injuries had been a common theme for the family.
"I think all of us have had cartilage cut out of our knees including my father. Some of my brothers and my dad have had surgery twice on different knees. A lot of lacerations. We've all suffered from back pains, joint pains, neck pains over the years," he said.
In the last financial year, ending mid 2021, ACC recorded the highest number of claims from construction site injuries in a decade.
The number of construction site soft tissue injuries - most commonly strains and sprains - topped 91,000 between 2017 and 2021, it said.
Injury prevention programme leader James Whitaker said those were "pretty sad stats", and almost entirely preventable.
"There's a higher risk of injury in the construction industry than in most other New Zealand industries," he said.
"Roughly about 10 percent of the New Zealanders who are injured at work are working in the construction sector."
It comes with costly consequences, including almost $400m in payouts, and more than half a million days off work in five years.
According to 64-year-old plumber Ra Puriri, it also impacts people's ability to work once they return to the tools.
He injured his knee in 2020 while lifting a tank on loose gravel.
"Now ... I can't crawl under houses. It's hard for me to climb up ladders, It's difficult. At least for me, at my age, it's been a struggle. But I've seen fellas a lot younger struggle with very similar things," he said.
He believed cutting down the number of construction site injuries meant changing the industry's "macho" attitude.
"Caring more for each other and not being afraid to speak out. And having the courage and the mana to express how you feel and protect yourself and other people," he said.
Whitaker believed tradies could learn from the most commonly reported injuries and not make the same mistake.
ACC has launched a programme with Construction Health and Safety [CHASNZ] called Work Should Not Hurt, which offers employers resources, tips, site visits, and workshops to help keep their employees safe.
It is part of a $3.9m investment in CHASNZ over two years.
"This is all about flipping it around. Instead of relying on hindsight, we can have foresight instead," Whitaker said.
Master Builders chief executive David Kelly said there had been a lot of work done in recent years to tackle serious injuries on construction sites, including falls from height.
"But there's a lot of other injuries that [ACC and CHASNZ] are focusing on here - like soft tissue injuries - that I don't think have the same level of awareness."
It comes at a time when the industry is already under immense pressure from supply chain issues and worker shortages.
Kelly said it made economic sense for business owners to "do the right thing" and keep their employees safe on the job.
"All the more reason that we should focus on the things we can improve. If we've got a shortage of people with skills the last thing we want is for those people to need further time off work," he said.
Whitaker said he would know the programme was working when claims went down and there were more "happy people" at worksites.