This is the deal. Every member of staff needs to lose weight. Not because obesity is a problem here (that huge plate of sandwiches has hardly been touched) but because Robert - the tall guy with the dark hair - has promised to give pound;1 to charity for every 4lb collectively shed.

That’s why there is a progress chart on the wall and a set of bathroom scales on the floor. It’s also why the sandwiches have hardly been touched, and why the dozen or so people who drift in and out of the room this lunchtime seem much given to hilarity.

Actually, the jollity has several causes. Someone is recalling highlights of last summer’s trip to Weymouth, which is always good for a laugh. And someone else is reading out witty slogans from a mail-order T-shirt catalogue. Then there’s the lively discussion about safety protocol when a class of infants visits the local swimming baths.

Hang on. Infants? Safety? Oh yes. If you thought you had wandered into the chill-out area at some dot.com company, think again. For this is the staffroom of an ordinary English primary school.

At least in many ways it’s ordinary. There are temporary classrooms in the playground and a library crammed into a corridor, and, of 406 children on the school roll, one in three has special needs. But in other respects, Lent Rise county combined school, Slough, is far from ordinary.

Talk to the parents. “It’s just indescribable,” says one mother.“The staff are totally dedicated. I can’t believe there’s a school like this.” Then read what the Ofsted inspectors have to say. “This is an extremely effective school,” says the latest report, and an “exceptionally high proportion” of lessons observed were “excellent” or “very good”.

There is much talk of a general work ethic, of clear targets and high expectations. Teachers know exactly what they are doing, they work themselves and their pupils hard, and nobody is happier with this, it seems, than the children. Pupils’ attitudes and behaviour are “excellent”, the curriculum is “excellent”. Also “excellent” are the quality of care, the performance of the governors and the standard of leadership and management.

On that last point, the inspectors go further. The headteacher, they say, provides “inspirational leadership”, which is “charismatic and individualistic”. Clearly Lent Rise is an exceptional school, and Brenda Bigland is an exceptional head.

That’s her now, standing on the scales and complaining about how Robert torments them all. (And later that’s her grabbing a microphone, a prop from the Year 5 production of Bugsy Malone, to oblige the TES cameraman.) “It’s like a madhouse in there,” she says, leading the way to the relative quiet of her own office. But she is justly proud of the relaxed atmosphere in her staffroom, and delights in the way her young team treat it as a home from home.

Like every member of staff and every child in their care, the teachers, she says, are part of her family. And there’s a strong sense that, for once, this is more than rhetoric.

Take her policy with new recruits. “Before people start here,” she says, “I like them to spend a week in the school in the summer term; if they are in another school, I’ll pay for that. If they are an NQT, my offer to them is - this is going to sound bizarre - that they come home and live with me for a week. I drive them into work, I take them home, I feed them. We relax, we learn about each other - you know? It’s building the team.”

If they didn’t think it bizarre, the Ofsted inspectors certainly found this practice unusual (one asked a teacher if he had found it intimidating. “Not after the first hug,” was the reply). What they readily acknowledged, however, was that this management style clearly worked, enabling staff to “hit the ground running” when they clocked on in September.

Inviting staff to stay with her and her husband is just one of the strategies that has enabled Brenda Bigland to turn Lent Rise around in the seven years since she arrived. While her other techniques may raise fewer eyebrows, the extent to which they are transferable clearly depends on individual circumstances. But she is keen to share her ideas with the stream of heads who began visiting after Ofsted inspectors named Lent Rise a nationally outstanding primary school in 1996 and who will arrive in increasing numbers following this latest report.

“I’ve got this thing,” she says, “that if you have a wheel and it turns for you, offer it to somebody else, change a few spokes and it might turn just as well for them. That’s the game we play. And a lot of it does tend to work.

“I came into this school, which had a nice family atmosphere. But it was a school where parents wanted a higher standard. We had to start somewhere, and what I did was look at the organisation. People didn’t really know what guidelines they were following or where they were going, and so everybody did their own thing.”

Although Mrs Bigland was careful not to go in with all guns firing (“I began by working with the children on an individual basis, sorting out discipline and the uniform, giving them a sense of family”) the radical culture change she envisaged was not universally welcomed.

“People would ask, ‘Why should we do this if the Government is going to change it again?’ So I had to say, ‘It doesn’t matter what the Government is doing. Let’s look at what we want and need to do.’” Some of the longer-serving teachers left, but with a young team largely of her own choosing, Mrs Bigland at last felt free to make her mark. “When heads come round,” she says, “they ask how long it takes to manage the process of change and then to be able to sustain it. I tell them it takes two years of sheer hard graft - of putting in policies, systems and strategies.”

It is these policies, systems and strategies rather than her own personal charisma that Mrs Bigland would say are responsible for the transformation of Lent Rise from a school with falling rolls, vertically grouped classes and a reputation that placed it seventh on local estate agents’ lists. While some would question her modesty (“I don’t know what it is with her, but I wish I had some of it,” says one mother), even a casual visitor is unlikely to leave Lent Rise without having sensed the order - the unity - that pervades the place.

It is as evident in the consistent design of classroom displays as in the universal colour-coding of files and folders (“If it’s orange, you know it’s ICT”). Any child - any supply teacher - can walk into any classroom, and the system is there to support them, says Mrs Bigland. “You can’t ask children to be independent learners if they’re going into chaos, can you? It’s all about calm. That way, you don’t get stressed teachers.”

But it’s behind the scenes, in the field of people management, that Brenda Bigland’s systems and strategies really come into their own. Several of her innovations seem to be based on the simple principle of pairing. For example, she has two assistant heads rather than a single deputy, and her NQTs are always assigned two mentors - a mentor trainer and a mentor friend (“so that when they’re hacked-off with the rest of us, there’s always somebody to turn to”).

Year bands are divided into two classes, each of which is assigned a single teacher. These pairs support each other, planning and cross-referencing together. “They know what the stretch factor needs to be. If one group’s getting this, what should the other group be getting? They’re always counterbalancing, making sure they’re keeping the challenge right for the children.”

Mrs Bigland is big on career development, and an important tool here is the professional portfolio - an ongoing statement of each individual’s aims and achievements that Mrs Bigland describes as “a living CV”. She says she “nearly gave one head heart failure, explaining what a professional portfolio was”. But the idea came to her before the first Ofsted inspection, and she says it gave her teachers enormous self-confidence.

“I want staff to know what they have done. It’s a celebration of their contribution to standards in the school. They found they waltzed through the Ofsted interviews because it was all in there - they build their portfolio as they go. You get used to a system that says, ‘Okay, what are we looking for, what have we done, where’s the evidence?’ And it’s simple - it’s not onerous, and they get time to do it.”

While the portfolios take much of the stress out of Ofsted inspections, Mrs Bigland says they also help staff to lead special projects involving other forms of outside assessment - one of her key strategies for keeping standards high.

“Who’s watching me to keep me ahead of the game - to check that we’re still giving the best to the children? As the line manager here, who’s challenging me? The only way is by letting my staff lead projects that give them the development they need and check it out for us. So, in the past 18 months we have measured our improvement against national benchmarks and have achieved the Investors in People award, quality marks for literacy and numeracy, the Active Mark Gold for Sport, the Charter Mark and an Achievement Award from the Department for Education.”

An NQT was responsible for the work that brought the Active Mark Gold for Sport. “And why not?” says Mrs Bigland. “If you have that sort of inspiration, why hold it back because you’re an NQT?

“Ofsted described this as being a culture in which no one is prepared to be or accept second best, and it does permeate right through to the children now. I don’t ask them to compare themselves with someone next to them, but to compare themselves with themselves. One of the things we’re known for is tracking children. That’s why we practise SATs - not for practising’s sake, but so we can keep an eye on these kids.”

If she’s not afraid to speak in the language of business (she has a Masters degree in institutional management and educational administration) that’s probably because she sees education as a business enterprise. “Too many people refuse to acknowledge that education is a business these days,” she says. “It has to be, because you’re looking at getting the best for the client, and the client is the child. But if I walked into that playground now, I’d be knocked over in the rush for hugs. It is a business, but it’s a business with a heart.”

As if to prove her point, she frequently finds unexpected gifts in her room, from parents, children and staff. “I came back from a school trip and there were a dozen red roses on my desk. We get thank-you cards from parents, which we didn’t get in the early days. Teachers say they aren’t appreciated, but here it’s beginning to happen.”

If being appreciated is one good reason why staff recruitment is never a problem at Lent Rise (one Ofsted inspector remarked that he wouldn’t mind a job there himself), the school’s reputation for training and career development is another. But this also makes staff retention tricky. “Obviously I take the bright young things,” says Mrs Bigland, “and after a few years they move on to get promotion elsewhere. But that is right and good. I would hate to hold anyone back.”

And, at 49, where does she go from here? “I have no idea,” she says. “It depends what makes my eyes light up. But there’s no point going to another school. It would be nice if the systems and strategies we use here could be offered a little more widely to heads. We’ve been through the pain barrier, so why does someone else have to go through it?

“We have so many stressed teachers, but a lot of the time it’s because they are all chasing each other’s tails. You read in the media about how everybody’s tired and stressed, and I would acknowledge that fully. But I would just say that if we could have a few systems in schools - if you just gave people the tools - you wouldn’t have those stress levels.”

LENT RISE’S HOUSE RULES

Ensure safety of the children at all times This includes being on time yourself for lessons, changeovers playground duties, clubs.

Plan well Do your lessons have pace and challenge? Are you prepared with reinforcement and or extension activities for those who do complete set work?

Assessment must be thorough Tracking to show achievement levels linked to target-setting with pupils is essential. Keep up with the timetable set by the assessment co-ordinator. If you do not, you will suffer at ‘catch-up’ time and so will the child.

Classroom organisation and management must be exemplary Chaos does not breed pride Display Does it celebrate work done in the classroom? (If not, why not?) You are proud of the work you have done with children, so display it well.

Communicate With each other - support makes the team more effective; with parents - if the child is doing well, tell them, if the child needs more support, tell them and ask for a partnership; with the wider world - lead others and celebrate all that you have done to raise standards.

Professional portfolios Keep these up to date. Remember this is your proof that: your intervention has raised standards in your class and year band; you as a co-ordinator have raised the profile of, and standards in, a subject throughout the school. This is not about being selfish and holding on to good practice. It is about sharing and raising standards for all children and your part in this.

Discipline and school ethos Is yours a caring discipline, showing an intolerance of bad behaviour that is detrimental to good progress and linked to positive strategies which ensure good behaviour?

Role modelling What are your standards as regards dress, attitude, determination to succeed and never accepting second best? Ensure the children learn from you.

Keep your sense of humour Teaching is a hell of a vocation and, if it is done within the right team ethos, it still has wonderful rewards.