215 construction sites have been closed since July due to poor height safety work practices.
The Ministry of Business, Innovation and Employment visited a total of 760 construction sites, with more than 400 actions taken against them.
Project Team Leader Marcus Nalter says the level of non-compliance is so concerning they're extending the first phase into the Christmas season.
He says half of the sites required unsafe work at height practices to be stopped and remedied, with over 160 warnings issued - requiring immediate action.
Mr Nalter says there’s no excuse for the huge amount of unsafe work sites, and doing nothing is not an option.