A secondary school in Co Offaly which harvests rain water for use by students has won this year's 'Overall Green Business Award'.

The Department of Education and Skills won the prize for the building at Coláiste Choilm in Tullamore at an awards ceremony in Dublin last night.

The building, which was described as “a living laboratory for testing technologies” has an A2 energy rating.

It has 87% rainwater recovery and has a 45% carbon emissions reduction.

The judges said the entry offered leadership, excellence and commitment to the sustainable design, build and operation of all new Irish schools.

The Green Awards are now entering their fourth year. They aim to encourage best green practice in big businesses as well as among small voluntary groups.