The construction sector gap could soon be filled by prisoners as the Department of Corrections pushes to teach inmates trades.

The aim is to have 900 people practising trades from behind bars in the next couple of years and around 100 homes built a year.

Corrections Chief Custodial Officer Neil Beales says they have been training inmates in trades for years.

"We have been involved in trades training with prisoners for a long time. The houses at Rolleston that we have been building post-Christchurch."

He says there is a huge amount of interest among prisoners.

"Talking to the guys and seeing the difference it makes in their lives. Guys who never knew they could do this kind of stuff."

"If they can go out of prison and actually get fully employed work, it makes a difference for not just them but for their families and communities as well."

LISTEN ABOVE AS NEIL BEALES SPEAKS WITH MIKE HOSKING