Temporary classrooms are to be put up at Claypotts Castle Primary School in Dundee in an effort to meet demand for places.
The school opened to pupils just seven years ago but the city council has been forced to accept that it is not big enough.
The temporary classrooms, costing £70,000, are believed to be the best option as they will have the least impact upon playground space and can be set up ahead of the start of the new school year.
A spokesman for the council said: “This school was opened seven years ago and in that time the roll has increased.
“We have anticipated that this trend will continue and, therefore, are responding to that need with the addition of a modular classroom adjacent to the existing school building.”
East End councillor Lesley Brennan said the need for the portable classrooms highlighted class size issues and demonstrated that the council “got it wrong” when planning the school.
“The council uses its own forecasts when designing schools in the city and it always provides just enough accommodation and no more,” she said.
“In this instance, the school roll has increased, both as a result of people moving into the area and increasing birth rate.”
Mrs Brennan said she has been contacted by local people concerned that the new facilities will be built opposite their homes.
Residents Rachel Laing and Jemma Kelly said they had not been contacted about the proposals and said the classrooms would “completely spoil” their outlook.
“We are really annoyed that no one has even bothered to respond to our concerns,” Rachel said.
Another resident, Ruth Rose, said: “The only reason we found out about this is because I’m a cleaner at the school and I overheard it being discussed. I have complained to the council.”
Mrs Brennan said she had raised concerns with the city’s director of city development Mike Galloway.
In a letter to the councillor, Mr Galloway said the solution had been selected after careful consideration and also moved to lessen residents’ concerns that football pitches would disappear.
He said: “The preferred choice of a modular classroom is based on a number of considerations, including the desire to maintain the amount of playground and the speed within which such a proposal can be implemented.
“Discussions have taken place with neighbourhood resources, who have confirmed the proposal will not have an adverse impact on sports pitches.”