The single module design units, with the first of 40 leaving the facility on Thursday, will be sent to temporary housing sites in the Northern Rivers and are being constructed through Corrective Services Industries (CSI) at Cessnock and Goulburn Correctional Centres.

Minister for Corrections Geoff Lee said the project provides vital support for flood victims while also aligning with the NSW government's goal to reduce recidivism.

"It's great that Corrective Services can support the people of the Northern Rivers and, at the same time, enable inmates to upskill in a range of trades," Mr Lee said.

"This project is also a testament to our staff, who are dedicated to the security of our State and the rehabilitation of offenders."

The new units are part of a $350 million investment by the NSW Government into temporary housing for flood-affected communities.

Minister for Emergency Services and Resilience and Minister for Flood Recovery Steph Cooke said the construction of modular homes through CSI is just one of the many ways the NSW Government is providing medium term housing solutions.

"Housing is one of the biggest challenges facing our flood-affected communities. The NSW Government is looking at all available options to provide people with a roof over their heads as the recovery progresses," Ms Cooke said.

"Programs like this are key to providing the temporary accommodation needed so flood-affected residents can get on with the enormous task of rebuilding as quickly as possible."

The single-level dwellings were allocated to CSI, from the Department of Education, before being stripped and refitted to house up to two people.

The units, which include a kitchen, bathroom, laundry and air-conditioning, are going to temporary housing sites in the Northern Rivers.

CSI is the commercial arm of CSNSW and operates more than 100 business units and service industries teams strategically based across metro and regional centres.