Former head teachers and past students joined current staff and pupils to celebrate a major refurbishment at Heron Way Primary School.
MP Francis Maude cut the ribbon to officially open the new area of the Horsham school on Thursday (October 23).
The development, which has been two and a half years in the making, includes four new classrooms, two halls of different sizes and a high tech learning resource centre.
Head teacher James Crump said: “They have given us a very flexible, adaptable learning environment for the children, which is fun as well.
“Thank you to parents, children, governors and my amazing staff who have been incredible over the last year. It is unrecognisable.”
He also thanked site manager Martin Payne for his help during the project.
Two former head teachers that spent a combined 29 years at the primary school commended the work.
Maurice Jones took over in 1982 and Carole Hatfield succeeded him in 1996.
Mr Jones said: “It is absolutely marvellous and a great environment.
“We had no computers at all when I started, and when we did get them they were a real nuisance because they kept breaking down.”
Ms Hatfield said: “It is a tremendous difference - the total environment for the children is so much better.”
Mr Maude added: “I have visited this school before and was very impressed, so it is a great pleasure to be a part of the opening.”