He says it's not only builders who are needed - one company is trying to repair thousands of driveways.
Mr Kohn says the target of 900 new tradespeople needs to be met, because the demand is there.
A social media campaign will be in place and a special bus will tour the South Island to attract workers to fill the skills gap.
Philip Aldridge from the training group Infra-Train is cautiously optimistic the hundreds of people needed can be found.
He says it's an exciting opportunity for job hunters and it's a chance for Cantabrians and others around the country to learn new skills and gain employment for the next few years.