North Yorkshire - Schools' crisis needs £47m

Some of the hundreds of such classrooms in the county have been in place since as far back as the 1960s.

And even with the help of new Government cash that could be available from next year, the extent of the progress which could be made into replacing them will be limited.

In a report on the issue to the county's planning committee, director of education Cynthia Welbourn points out that North Yorkshire has a total of 390 schools with a pupil population of 86,000.

Of those schools 212 have at least one temporary classroom and in many cases even more. One school now has a total of 13 such classrooms and several have up to ten.

There are 329 single units, 88 double units, two trebles, one quadruple and, in one case, even a temporary hall.

The oldest 20 date back to the 1960s, 98 were installed in the 1970s and 79 in the following decade. In the 1990s their numbers exploded when 150 more were installed.

The list does not include 50 prefabricated units installed immediately after the Second World War - where the standard of accommodation is regarded as poorer than many of the temporary classrooms.

"Temporary classrooms are often used when the capital bidding system cannot be used to generate sufficient capital to provide permanent accommodation," said Miss Welbourn.

"Once on site it then becomes very difficult to prove the case to the Department for the Education and Skills that the temporary buildings should be replaced by permanent."

The temporary classrooms are inspected annually but only a minimal proportion of the education authority's £6.4m repairs and maintenance budgets needs to be spent on them.

And Miss Welbourn added: "The 'payback' in maintenance terms of replacing temporary classrooms with permanent buildings will be limited, given that it would take very significant amounts of capital to make inroads into reducing the reliance on temporary buildings."