When Anne Burrell became head of the John Bentley grant-maintained school in Calne, Wiltshire, in 1994, she asked every member of staff what was the one thing about the school they would change. Ninety-eight per cent replied that, after 25 years of pupils having to walk a quarter of a mile between lessons, they would have the school rebuilt on a single site.

Four years later, that rebuilding is complete. Land which once accommodated the John Bentley north wing has been sold off for housing - and without the local authority being required to give its consent. Last September Anne Burrell presided over the first ever whole-school assembly at the John Bentley, its 1,150 pupils gathered together in a capacious and wonderfully equipped new school hall. The now single-site school had its official opening last month.

It is the kind of story guaranteed to set headteachers across the country dreaming and plotting about how to better their own schools. What was involved in the John Bentley school turning entrepreneur - and how easily could other schools follow suit?

John Bentley become a split-site comprehensive in 1974, when the Old Bentley grammar school joined forces with the Fynamore secondary school, a quarter of a mile down the hill. To begin with, the two operated almost as separate units, with parallel year groups on each site, but in 1987 the two wings were reorganised to house different subjects.

This meant every pupil walking - “commuting” it was called - from one wing to the other every day, however bad the weather.

“It was horrific,” says Anne Burrell. “When you had about 600 pupils coming up from north wing and another 600 coming down from south wing, it was like a kind of tidal wave. You had to time it so they wouldn’t all be crossing the A-road at once. We were lucky never to have a serious accident.”

The split-site also created considerable timetabling problems: managing two virtually separate staffs was tricky, says Anne Burrell, not to mention the pupils, who could play the system to miss lessons.

Selling off one site at that time would have meant the school giving half the proceeds to the local authority. Wiltshire was not sympathetic to the school’s building plans because it was not convinced that a single-site school could meet the rising demands of Calne’s expanding population. But once it became grant-maintained, the school did not have to convince people at county hall; it was the Department for Education and Employment that had to decide.

In July 1995, Anne Burrell approached the Funding Agency for Schools, the body that oversees grant-maintained schools’ finance, and was quickly put in touch with Miller Construction. A DFEE architect approved the project in principle, on the basis of the school’s 30 acres of land on the south wing site. Then, in September 1995, the Conservative government, still wooing grant-maintained schools, announced that they could keep not 50 per cent but 100 per cent of the money from any sales of land.

This gave John Bentley the green light. For the next two years, the school busied itself with scraping together every possible bit of funding to finance the pound;4.4 million project. The sale of the 10 acres on the north wing to the building firm, McAlpine’s, raised pound;2.9m - twice as much as anticipated. Other funding sources included money from the Government for new buildings, allocations for health and safety and for rising pupil numbers, as well as the school’s own savings.

“We were living on tenterhooks,” says Anne Burrell. “There were many points when the whole thing could have fallen through.”

The timing was crucial. Within six months of the 1997 election, the DFEE called a halt to funding decisions of this kind. Under Labour, the funding agency no longer makes allocations without the agreement of the local authority and schools may not necessarily retain 100 per cent of sale profits. “There was an opportunity,” says Anne Burrell, “and we seized it.”

By early 1997 the plans had gained consent. Building began in August 1997, and was completed by August 1998. Miller Construction, the firm of architects and builders, were “superb”, says Anne Burrell, as were the quantity surveyors, Michael Edwards and Associates, whom the school hired as consultants to oversee the operation and ensure they got the best value for money.

Living with builders on site for a year was testing for staff and pupils alike - providing some interesting curriculum opportunities along the way.

But the result is a single-site school that is the envy of heads for miles around. It includes the assembly hall seating 350, a new 28-classroom teaching block, with handsome library and computer suites and superb facilities for art, technology, music and drama. Some general refurbishment and modification of existing Fifties buildings has given the whole school a facelift and even the staffroom is attractive.

“There’s a real feeling now of being one school as opposed to north wing and south wing,’’ says Alan Aggett, the head of art.

“Not having to commute is brilliant,” says pupil Jenny Bishop, 17. “It used to be hard to settle down at the beginning of a lesson. It feels better having all the teachers in one place, too. It means they can talk about us if they need to - and that benefits us.”