Thousands of children are being taught in pre-fab classrooms and school halls as the construction industry remains at capacity.

In Auckland, 45 per cent of the 805 new classrooms added to state schools in the four years to last June were temporary.

Infrastructure New Zealand chief executive, Stephen Selwood, told Mike Hosking that the industry's been at capacity for the last three years.

"There's an accord underway right now with the industry to figure out how we can address this issue, and the reality is that i think ti could be another couple of years before we get on top of it."