Schools will be prosecuted if they cannot get a certificate showing their carbon footprint. That means 17 inspectors visiting 20,000 schools ..
Headteachers face pound;1,000 fines in October if they do not obtain an official certificate showing how energy efficient their school is.
But TES inquiries reveal there are only 17 accredited assessors listed in Britain - and those few are able to name their price to inspect schools and issue certificates.
Now some heads say they will refuse to comply with the new legal requirement, hoping that local authorities will be unable to deal with a mass boycott.
Mike Stewart, headteacher of Westlands Secondary School in Torquay, said headteachers were being made liable for problems such as old boilers which were controlled by local authorities or private finance contractors.
"We're all committed to energy efficiency and we all take our fuel costs very seriously, especially at current price levels. But this is out of our control," he said.
"I don't think most schools will get the certificates - we don't have time, with the summer holidays intervening," he said. "This just places additional stress on already stressed-out headteachers."
There are 40,000 public buildings which are required to get Display Energy Certificates, and about half of those are schools. Only small one- or two- room primary schools will be exempt, the Royal Institution of Chartered Surveyors (RICS) says.
Headteachers and other facilities managers are trying to book one of the 18 accredited assessors, but they are unavailable, or are charging between pound;1,000 and pound;2,500 for a day's work.
Patricia Monahan, RICS project manager, said: "We do think it will be difficult for schools and other public building managers to comply with the requirements by October, because of the low number of assessors around."
The TES has obtained local authority guidance to schools that discloses serious concerns with government attempts to push through the scheme at "the 11th hour".
"If the UK fails to implement this they will be in contravention of the EU Energy Performance of Buildings Directive (and probably subject to a heavy finepoor publicity)," the guidance says. "Now the pressure is passed to local authorities to deliver, using software that is constantly being revised as bugs are found and corrected."
The Chartered Institution of Building Services Engineers (CIBSE), the biggest training and accrediting organisation, has accredited only nine assessors.
Jacqueline Balian, CIBSE director of information, said heads should collect and log verifiable data on their school's energy use, while they wait to get a certificate. But she warned they might face strict enforcement if they failed to get a certificate in time.
"Schools will be in contravention of the law if they don't meet the deadline," she added. "We are right on the edge of the EU deadline and the Government can't turn its back on that."
A spokesman for Communities and Local Government insisted that accreditation for 600 assessors was "in the pipeline".
"We would expect schools working with their local authority to negotiate the most cost-effective deal," he said.
"As well as measuring a building's energy efficiency, the certificate also makes energy-saving recommendations which could result in significant financial savings."
DISPLAY ENERGY CERTIFICATES - WHAT DO THEY MEAN?
State schools whose floor area is larger than 1,000sq metres must obtain and publicly post a Display Energy Certificate, showing the building's energy consumption, by October 1.
Accredited energy assessors charge between pound;1,000 and pound;2,500 to inspect a school and issue a certificate and advisory report, depending on the school's size.
The advisory report should offer suggestions on how headteachers can reduce the school's energy consumption.
A head should immediately arrange for a staff member to begin logging verifiable data about the school's energy use, so the assessor can calculate its carbon emissions.
The occupier of a school (usually the headteacher) can be fined pound;500 for failing to display a certificate, and pound;1,000 for not obtaining the advisory report.
For information about getting certificates, visit: www.rics.org or www.cibse.org.
To find an accredited assessor, visit: www.ndepcregister.comsearchAssessor.html.