Master Builders Federation chief executive Warwick Quinn said it would help builders take on new apprentices now, despite the depressed state of the industry, so trainees would be ready when the rebuilding of Christchurch peaks in 2014 to 2015.
"Whatever policy delivers that is almost crucial really because we have a shrinking housing sector. Our capacity has gone," he said.
"Yet we have this mountain of work that is in front of us given what's happened in Christchurch and the leaky buildings syndrome and the likely economic recovery."
Labour's policy effectively matches the National Party's youth employment policy, which was announced last month, and raises it by an extra $44 million a year at its peak in 2013-14.
The leader of the Mayors' Taskforce for Jobs, Dale Williams, who has campaigned for action on youth unemployment for 10 years, said both parties had finally focused on the issue.
"This is a fantastic time and place to be," he said.
Both parties have adopted the taskforce's plan to make sure every young person who leaves school aged 16 or 17 gets help if required to find a job or further training.
National also plans to expand free places for 16 and 17-year-olds in trade and service academies and tertiary education from 3500 at present to 12,500 by 2014 - cutting 9000 off June's toll of 24,000 teenagers who were not in employment, education, training or caregiving.
Labour has promised to continue that policy plus provide work or training for a further 5460 young people a year by 2014 - a net 2000 through the apprenticeship subsidy, 1500 in extra free places in tertiary education, 1000 in extra group and shared apprenticeships, 500 on a new seasonal work scheme, and a net 460 in expanded Conservation Corps places partly funded by scrapping military-style camps.
If Labour's figures are correct, its total plan would remove 17,560 from the tally of 24,000 inactive young people by 2014.
Mr Williams said this was achievable, as fewer than 250 people under 25 were on the unemployment benefit in December 2007.