He said business surveys over the last two years have shown positive results on the employment rate.
"It's going to reflect that business confidence is high and businesses are employing people because they're confident they've got work in front of them - particuarly residential construction and civil construction," Mr Collins said.
He said the off-season for tourism and accommodation was also becoming shorter.
"Tourism and accommodation providers have experienced quite an uplift in business well before Labour Weekend, which is traditionally when things start. So downtime gets shorter, which makes it a bit easier for their cashflow and bank balances and makes it more sustainable."
Mr Collins said he expected stable growth in both residential and civil construction would provide a solid 10-15 years of work for the industry due to the growing population.
Nationally, unemployment fell below 5 per cent for the first time in nearly eight years.
An extra 35,000 people were employed in the September quarter, with half of the growth occurring in Auckland, and a fifth in Otago.