The Capital could be left with a “gaping hole” and a bill for hundreds of millions of pounds to provide enough school places for children amid a projected population explosion.
Education chiefs will bid for a share of £1 billion of additional funding from the Scottish Government to build or expand schools in preparation for rising roll numbers.
Around £500 million would be needed to provide enough space for a growing population in Edinburgh, with house-builders footing part of the bill.
The Capital is expected to grow by around 40,000 people between 2016 and 2026 and see a further 36,000 increase by 2041. Currently, secondary schools have a capacity of 22,200 pupils – but pupil numbers are expected to rise from 19,812 next year to almost 25,000 by 2028.
At the new Boroughmuir High School, which only opened its doors in February this year, additional accommodation for rising rolls is already needed.
In the meantime, the school said it will accommodate all pupils through “more efficient timetabling”, and changes to the catchment area may be considered.
The Royal High School will also experience rising rolls – but any new accommodation will not be in place until at least August 2021. Firhill High School may also require space for more pupils.
The council predicts extra capacity for up to 600 pupils at James Gillespie’s High School over the next ten years, while primary Gaelic Medium Education places at Bun-sgoil Taobh na Pairce are expected to rocket from 376 this year to 721 by 2028 amid a current capacity of 434.
Projects to tackle rising rolls in high schools in west Edinburgh will also need to be considered, along with 14 primary schools across the Capital.
Education, children and families convener, councillor Ian Perry, said: “Edinburgh is growing and that comes with more families, more young people and therefore puts pressure on schools.
“In the south and west, there’s five new primary schools being built to accommodate the house-building that has been agreed by the planning committee.”
He added: “The price tag is massive – you are talking about half a billion pounds of infrastructure. For primary schools it comes from developers, so you can take about half of that out, while the others, the council and the Scottish Government will pay for. We will bid into the £1bn that the Scottish Government have made available.”
Last month, the Scottish Government announced it will invest an additional £1bn in rebuilding and refurbishing schools from 2021.
Green education spokeswoman Cllr Mary Campbell said: “Up to 20 schools either need to be built or to be extended to cope with rising pupil numbers. That is quite apart from the need to revamp or rebuild existing schools which have come to the end of their shelf-life. Add to that the commitment to almost double nursery provision by 2020 and the pressure is obvious.
“The city has to make sure it is geared up to deliver what is needed for schools or risk a gaping hole in places over the next 10 years.”