Two private school headmasters are campaigning to help refurbish a crumbling comprehensive

It is a unique example of co-operation between the state and private sector of schooling. Normally, co-operation means the independent schools open up their plush sports facilities to pupils from the neighbouring state school or share a teacher with them. In this case, though, the two private school headmasters concerned have rolled up their sleeves and got down to some serious campaigning to improve the facilities at a state school.

Kings Langley, a secondary school in Hertfordshire, has been forced to soldier on in classrooms that were labelled "temporary" when they were first set up around 25 years ago. The school just missed out on Labour's Building Schools for the Future programme when the current Education Secretary, Michael Gove, brought the shutters down on it nearly two years ago.

Enter Dr Anthony Seldon, principal of Wellington College, and David Lewin, headmaster of the City of London Boys' School – both of whom serve as advisers to the Government – who were genuinely shocked by the conditions pupils at the school had to endure.

As a result, they joined forces to plead with ministers to rebuild the crumbling comprehensive school. In a joint letter to Mr Gove's department (it was sent to the Government's Schools Commissioner, Elizabeth Sidwell), they warned that conditions at Kings Langley "pose a constant risk to the health and safety of pupils".

Following the decision to axe it from the school building programme, the school is now seeking funds for rebuilding from the Coalition Government's priority capital programme.

The action taken by Dr Seldon and Mr Lewin is unprecedented. However, the two felt moved to act because the school's attempt to win outstanding status from Ofsted, the education standards watchdog, was being being thwarted by the conditions the pupils have had to endure.

Many of the pupils are taught in the 25-year-old "temporary" classrooms and the school's assembly hall has to be closed when there are high winds because of the risk of glass from the windows falling on those inside.

The school is a specialist performing arts college, even though the space for pupils to perform is inadequate. Despite these handicaps, it has earned a reputation as a top-flight dance school and its pupils have also won international recognition in a rock music competition.

In their letter to Dr Sidwell, the two heads said: "Following years of decline and an Ofsted report in 2000 that placed the school in the bottom 5 per cent of similar schools nationally, the school has under gone a radical transformation and is now a 'good school with many outstanding features'.

"The current leadership team are determined that the school will be outstanding in every respect within two years but are frustrated by the considerable constraint placed on further progress by the inadequacy of basic facilities and the very poor state of repair and quality of the current buildings."

They added: "The Ofsted report of 2010, although very positive, was clear that further progress would be hampered by the poor state of repair of the buildings, the lack of adequate facilities and the fact that physical provision was clearly 'not fit for purpose'.

"In comparison with similar schools, considerably more time and money has to be invested in basic repair and maintenance of the infrastructure.

"Rusting underground pipes, drains that are constantly flooding, extensive asbestos insulation and windows that fall out in high winds pose a constant risk to the health and safety of the students. Leaking flat roofs and a building that is past its 'sell-by date' do not match the aspirations of the children."

Mr Lewin, who has visited the school, added: "I think the school needs all the help that it can get to rebuild what I think is a positively dangerous campus." In the past decade, the school's exam results and artistic achievements have improved by leaps and bounds under its new head teacher, Gary Lewis.

"It has developed its links with the City of London Boys' School since the two independent school heads were impressed by a presentation it made at a conference. Now it has taken the idea of compulsory prep at school from the independent sector for pupils who fail to hand in their homework three times.

Gary Lewis says that as a result of introducing prep many pupils now like to do their homework at school because they do not get enough support to do it at home. Mr Lewin said he had also been impressed by the school's mentoring scheme that helps pupils who are struggling to catch up by placing them under the watchful eyes of older pupils.

However, Kings Langley cannot make that final leap to being declared an outstanding school because of the state of its buildings, which could never be given a grade one rating by inspectors.

In their letter, Mr Lewin and Dr Seldon add: "By any measure, the poor state of repair and accepted inadequacy of the buildings coupled with the almost complete absence of basic facilities makes it virtually impossible for Kings Langley school to deliver an education that 1,100 people deserve."

Charlotte Noddings, a 16-year-old pupil at the school, says of the dance group: "I think we all work hard together despite the facilities we've got."

John Brooks, aged 18, an A-level student, adds: "A lot of people were scared when a window collapsed. The level of work we produce from here is of a really high standard and it has improved since I came here but the buildings have not.

"Just think what a sparkling advance we could make if the buildings were outstanding as well. We would urge that Kings Langley school be considered as a high priority for the [building] programme and feel that a visit to the school site would confirm this evaluation."

Mr Gove has visited the school and afterwards he wrote to say it was under consideration as part of the Government's school building programme but that he could not comment further until all bids had been assessed. That is still the current state of affairs as ministers grapple with the competing demands for cash from their truncated capital building programme.

The school was built in the 1960s as a secondary modern at a time when Hertfordshire still retained a selective education system. It was intended to cater for 400 pupils but soon turned into a comprehensive. It still has to battle against neighbouring schools, which retain a partial element of selection for pupils.

"It should have been put in special measures but wasn't," says Mr Lewis. "It was a nail in the coffin because it was always struggling in terms of parental confidence. When you've got a school where nobody wants to come, you pick up children who don't want to be here – the children who can't get into other schools."

That is all behind Kings Langley now and it is flourishing under Mr Lewis's headship, with growing numbers of parents sending their children to it. It is "good with outstanding features" – but the buildings are not one of them. What has happened at Kings Langley is an excellent example of the two sectors coming together to campaign for a common end.

There is a third element in the equation, though, before that partnership can have any success: the Department for Education.

Meatloaf once had a hit record with a song called "Two Out Of Three Ain't Bad". It was not, of course, referring to the co-operation of partners in the education service. The lyrics "I want you, I need you but I ain't never going to love you" give that away immediately.

However, in the context of Kings Langley school, two out of three partners acting in harmony is not enough.