The 11- and 12-year-olds sit quietly in their seats, in places carefully selected for them by their teachers. They are expected to remain calm, with no running around or standing. Not unusual for a school, you might think, but this is not a lesson: it’s breaktime for Year 7 pupils at a London free school.

For one mother, the arrangement is preventing their children from “blowing off steam”. For another, it has led to them becoming “little firecrackers, wound up very tightly”.

The school is Bolingbroke Academy, which opened in Wandsworth in 2012, in the grade II listed home of the former Bolingbroke Hospital. It is one of an increasing number of schools for which concerns are being raised about the effects of operating on a constrained site.

The growth of the problem has persuaded one teaching union to survey its members, following complaints about the issue.

‘Limited internal play space’

In 2011, when councillors were considering the planning application for Bolingbroke, the chief concern was that “the site was not large enough for the proposed school to accommodate up to 800 pupils”. The limited circulation space for students and teachers was discussed, as well as plans to use Wandsworth Common for some sports because of the site’s limited facilities. Planning officers “acknowledged the constraints of the site”.

The mother of one Year 7 pupil says school leaders told her that the seated breaktime was one way of coping with space limitations.

While the school, which is sponsored by Ark, declined to comment, its website acknowledges that it has “limited internal play space” and that it uses staggered breaktimes to “enable pupils to make good use of it”.

A growing number of schools are having to cope with similar physical constraints. In some cases, the concerns focus on sites found for free schools; in others, it is the government’s Priority School Building Programme (PSBP).

Now, the NASUWT teachers’ union is planning to survey its members to find out the extent of problems with PSBP, after receiving complaints from members.

Wayne Bates, a national negotiating officer, says the union has heard “a lot of stories about very poor-quality rebuilding, and teachers not being happy with things like corridor width and the size of classrooms”. He adds: “It’s two issues: we have got, perhaps, rebuilds that are not big enough, but we also have these schools that are bursting at the seams.”

The issue is rapidly rising up the educational agenda. A National Audit Office (NAO) report, published in February, says that because of a shortage of sites for free schools, the Department for Education is using “properties not traditionally used for schools”. Of the free schools that have a permanent home, 11 per cent are in former office accommodation, 5 per cent are in the buildings previously owned by the emergency services and 3 per cent are in former industrial sites.

“The department has not yet assessed how these unconventional school buildings are working in practice,” the report notes.

Last month, the Commons Public Accounts Committee heard that two-thirds of free schools first open in temporary homes.

The coalition government brought in PSBP to replace Labour’s Building Schools for the Future programme and cut the cost of school rebuilding. In this, it has been successful, with the NAO finding that through simplifying design, central procurement and no longer funding some items, the cost per square metre is, on average, one-third cheaper.

It also states that PSBP schools “are cheaper overall because they are smaller”.

Some schools and councils told the NAO that they were concerned about how the DfE had reduced costs, such as cutting the size of communal spaces, although 85 per cent of school leaders expressing an opinion told the department that they were at least satisfied with their new building.

Cramped corridors and toilets

It is not just auditors and schools that have worries about the small school sites. Architects have raised similar concerns.

Last summer, the Royal Institute of British Architects called for an “urgent evaluation” of the long-term effect of new “baseline standards” that were set out by the Education Funding Agency, with “a particular focus on corridors and toilets”.

Its report, Better spaces for learning, raised the issue of “easily avoidable problems” caused by the narrower corridors.

“Crowded corridors impede the flow of pupils around a school, creating pinch points that increase stress levels and can exacerbate bullying problems,” it said.

Richard Daw, lead architect at Lungfish Architects, says that he has to address issues with constrained school sites “on a weekly basis”, and that it is a growing issue. For him, the circulation of pupils around a school is “most definitely” an issue.

Asked why the problem is increasing, he says: “Funding is always an issue. It’s an issue on every job we do. If you had endless pots of money, you would find a new site, but we are having to accommodate increasing numbers of pupils on that site, in a way that the flow of pupils around the school is still efficient.”

A DfE spokesperson says the NAO report suggests that school leaders are “overwhelmingly satisfied” with their PSBP schools.

“Of the 53 school leaders that have fed back, 85 per cent have been satisfied, or better, with their buildings. We will shortly be seeking similar feedback on free schools,” he says.

“Schools are designed to support educational attainment with robust buildings that are simple to operate and with low ongoing running costs. For free schools, we will open in high-quality temporary sites where appropriate, and we make sure that they are safe and suitable for educational purposes.”