A new school for Highfield will not be ready in time for its first term next September.
Instead 60 four to five year olds will start their reception year at nearby Astley Cooper School.
Delays mean the Hemel Hempstead Community Free School on the site of the closed Jupiter Drive School will not be completed until around Easter 2015.
Project manager Susan Poole said: “We absolutely hoped it wouldn’t happen but we have come to realise that it needs to happen. It is not ideal but it is the next best thing to being in our own school.”
She said it is also a great opportunity to build links with the secondary school and added that the reception age children will not be mixing with the secondary school’s students.
“We will have our own separate area,” said Susan. “Lunchtimes and break times will fit around the ones at Astley Cooper so they are taken at different times.”
The secondary school’s headteacher Eddie Gaynor said: “We look forward to meeting the children and staff and can assure them of a warm and friendly welcome into Astley Cooper.”