Education officials in Devon, where more than one-quarter of all children are taught in temporary classrooms, want government backing for a Pounds 38 million school-building programme.
A 166-page document, sent to the Department for Education and Employment, details the plight of children taught in the county's 1,325 temporary buildings, some of which date back almost 50 years.
A recent major structural survey of the 110 prefabricated concrete huts in Devon revealed serious problems and said long-term repair was impractical.
Four were taken out of service immediately because of safety concerns, and three more have been fitted with temporary steel strengthening.
All 60 schools with prefabricated concrete huts have been warned not to use them this winter as a build-up of snow on the corrugated roofs could be dangerous.
Local policy-makers have agreed to phase out all the huts during the next five years but replacements could cost up to Pounds 12 million.
Temporary accommodation is not the only problem affecting the authority - 49 primary schools still have outside toilets.
In addition, an increase in pupil numbers means that more than one-third of both primary and secondaries are now over capacity.
The local education authority claims that the high proportion of small, rural primaries serving scattered communities dictate the need to maintain and improve pre-1903 schools that have outdated and inadequate facilities.
Last year, Devon submitted a school-building programme totalling Pounds 36.75 million to the Department for Education and Employment. It approved Pounds 12.23m. The final programme agreed by the county council was raised to Pounds 15.7m.
The authority is now seeking approval to borrow Pounds 38m for its 199798 education capital programme. This comprises Pounds 8.2m to complete projects started this year and a further Pounds 29.8m for new schemes.