The county council is holding a series of public exhibitions to outline its plans to increase capacity at primary schools.
Across the county there has been a rise in demand for school places due to a rising birth rate, new housing developments and migration into Northamptonshire.
The county council has a statutory duty to ensure there are sufficient school places available and is planning to build a £3.14m extension at Henry Chichele Primary School in Higham Ferrers.
Demand for reception year places at the school in September last year was greater than the number of places available.
The situation will only get worse as 250 more homes are being built in the town.
The extension will add extra classrooms and multi-purpose rooms as well as office space, and will allow the school to increase the number of pupils it takes from 210 to 420.
Parents will have a chance to discuss the plans at a public exhibition from 3pm to 6pm on Wednesday.
Building work is also planned at several village primary schools as a result of the change from a three-tier to a two-tier education system in East Northamptonshire.
Schools including those in Nassington, Polebrook, Titchmarsh, Aldwincle and Warmington will have to be extended to accomodate the full primary school age range of four to 11. Previously pupils left at the age of nine to go to a middle school.
Public exhibitions have been arranged at each affected school for later in the month.
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