Plans for the project include a 2,600 m2 single-storey main building with 14 classrooms, a nursery and a hall.
The new building will have capacity for 450 pupils, including 60 of pre-school age.
External amenities include car parking, two multi-use games areas and a grass sports pitch.
Hirwaun Primary School’s existing teaching blocks will be demolished in phases as construction of the new building proceeds.
Overall project budget is £10.2m.
The main contractor won the project through the Southeast & mid-Wales collaborative construction framework (SEWSCAP).
Work is expected to complete on the project by spring 2021.
This is the fourth school Morgan Sindall ԭ will build for Rhondda Cynon Taf under the Welsh government’s 21st century schools programme.
Rob Williams, area director for Morgan Sindall ԭ, said: “We are excited to begin work on Hirwaun Primary School and to continue our delivery of modern learning environments in South Wales through SEWSCAP. We’ve established a great collaborative relationship with the council and the track record of well-received schools speaks to the effectiveness of long-term partnership.”
Councillor Joy Rosser, Rhondda Cynon Taf Council’s cabinet member for education and inclusion services, added: “The council has a good working relationship with Morgan Sindall ԭ, which was the contractor for the fantastic £7.2m Cwmaman Primary School, delivered on schedule in September 2018, with excellent engagement with the community throughout its construction.”