EDUCATION officers in North Yorkshire have revealed that it will cost at least £47m to replace temporary classrooms with permanent accommodation at schools across the county.

The authority has used government grants of £1.5m under the "new deal" scheme to replace some of the worst temporary classrooms at 13 schools, but officers have offered little hope of making serious inroads into the remainder of the backlog.

The 390 schools in North Yorkshire have 421 temporary classrooms erected since the 1960s but there are also about 50 prefabricated units, installed immediately after the war, where accommodation is considered poorer than in more modern buildings.

Education director Miss Cynthia Welbourn told the planning committee on Tuesday that the authority could get funding for new permanent buildings either by bidding each autumn to the government for permission to borrow money or by seeking help from department of education and skills initiatives which have operated since 1997.

She said basic need, the first priority in bidding for permission to borrow under the annual capital guidelines, had always been difficult to prove because of complex rules on the calculation of spare capacity in a school.

The authority also had to show that there were no other surplus places within three miles of a secondary school and two miles of a primary.

Miss Welbourn said temporary classrooms were needed because under the rules the authority was never allowed to borrow enough for more permanent places.

Over the past five years, when primary and secondary pupil rolls had risen considerably, the amount which North Yorkshire had been allowed to spend under the borrowing process had risen from just over £3m to just under £6m.

But Miss Welbourn said: "Clearly this will do nothing to replace the stock of temporary classrooms with permanent building as the estimated cost is £47m and the annual capital guidelines are meant to deal with current accommodation problems. The level is such that it barely allows us scope to keep pace with rising pupil rolls."

She said a new modernisation fund for local education authorities, being introduced by the government next April, could offer some prospect of replacing old temporary classrooms.

The amounts and the criteria governing their use would be announced later this month. The council would then have to decide how to use the money subject to government rules.

But Miss Welbourn warned: "Given the cost of replacing the council's stock of units the extent to which inroads into the backlog will be possible will be limited."

Repairs to temporary classrooms were minimal to ensure they remained weatherproof.