Blessington Educate Together National School wants to build a new single-storey temporary standalone prefab containing a new classroom.
A planning application has been submitted to Wicklow County Council for the works on Red Lane.
Also being proposed are two special education rooms and sanitary facilities.
The estimated construction value of the project is over €131,000 according to construction industry database Construction Information Services.
The total floor area of the development will be around 100 square metres to the rear of existing school building.
Meanwhile a planning application has been submitted for the demolition of existing 20 square metre single-storey retail unit on the Main Street of the town.
Being proposed is the construction of a new 41 square metre ground floor retail unit and 49 square metre one-bedroom apartment at first floor level.