Roscommon County Council has granted conditional permission for a major extension at Tarmon National School near Castlerea.
The proposed development includes the construction of a single storey extension to the rear of the existing school.
The extension will feature an SEN base, early intervention classroom, a multi-sensory room, three mainstream classrooms and an office.
The works will also include the demolition of existing storage areas while new car parking spaces will be added.
All associated site works and the upgrade of the foul and surface water treatment systems are included in the application.
County planners gave the go ahead for the development subject to 14 conditions.