Conlon Construction has won a £2.4m contract to carry out the second phase of improvement works at Davenhill Primary in Aintree, Sefton.
The new buildings designed by Capita Symonds, will contain eight classrooms, a library and study area, ICT suite, toilets and improved storage facilities. There will also be a new courtyard used as an outdoor classroom and play areas around the new buildings.
One of the existing school halls will be refurbished with a new heating system, lighting and other services and the school grounds will also be landscaped as part of the works.
Michael Conlon, construction director of Conlon Construction, said: "We take particular pride in our education projects and always aim to help pupils learn how to keep safe around construction sites."
Kath Coyle, head teacher of Davenhill, said: "Phase one successfully transformed the educational experience of our younger children and we can't wait to have comparable facilities for the juniors.
"Adults and children can see first-hand what a difference a purpose built space makes and the prospect of having this for us all really is fantastic."
The initial phase was completed in September 2010 and it is hoped the second phase will be completed in spring 2012.