St Andrews is a preparatory and pre-preparatory school standing in a leafy (no other word will do) suburb of Eastbourne. The place and its surroundings glow with prosperity, from the sunlight dappling the Sussex flint climbing wall to the shine of self-confidence on the faces of its eager pupils. Overlooking the sea, with facilities ranging from a “non-politically correct” shooting range to indoor heated swimming pool, darkroom, recital hall, playing fields, stacks of computers and the kind of child-friendly library that makes you want to curl up on a bean bag and start reading now, the school educates 407 children aged 3 to 13, of whom 90 are boarders.

Banish any thoughts of Dotheboys Hall. Although the school once had a headmaster who used to make every boy swim 15 feet in an unheated plunge bath (swimmer or non-swimmer) followed by half an hour of Swedish exercises before breakfast, its pupils, boys and girls, are so keen on the present-day regime that a group from Years 7 and 8 has just made a three-minute film on the joys of boarding, recently shown on Channel 4.

The school prides itself on its extra-curricular programme. Trips are a weekly occurrence, a French exchange an annual one, and St Andrews’ pupils compete in practically anything going on the south coast, from netball and squash to speaking and drama competition, also joining in the musical events of their feeder secondary school, Eastbourne College.

There is provision for special needs and English as a second language, outdoor education for children in Years 6, 7 and 8: you’d be amazed, says Hugh Davies Jones, the dynamic headteacher, how often it’s the less academic children who take the lead in practical activities. “We aim to develop self-confidence in everyone by developing what they are good at.”

“Everyone” is, of course, everyone who can pay. With non-boarding fees at Pounds 2,000 a term, it must be a pinch for the reportedly many state school teachers who send their children there. But the only selection is “selection by the pocket”, as Mr Davies Jones puts it. “We take all the children and we believe we can bring them all up to a good level of achievement,” he says.

With the scholarship-stream children gaining level 6 or above for their key stage 2 tests and touching on GCSE level for their entrance exams at 13, St Andrews offers space for high-fliers too. Is there any secret to the school’s success, discounting the “huge” benefits of small class sizes (average 16), parental prosperity and stability (“our parents tend to be very helpful”) and general willingness to buckle down?

Mr Davies Jones identifies three factors which could be applied even in a more difficult environment. First, he advocates some specialist subject teaching from the beginning of Year 3 (in music, art and PE) and throughout the curriculum from the beginning of Year 5. Although the school emphasises cross-curricular themes in its teaching, it’s probably easier, says Mr Davies Jones “for children to see patterns, certainly in history, if they see it as a separate subject and then look for connections outside”. Bryan Pryce, director of studies, adds: “It’s easier to audit time in the non-core subjects of history, geography and the arts if they are timetabled.”

The children are also divided by ability. “It’s an enormous help to be able to deal with them by ability.” In Year 5, St Andrews introduces setting for English, maths and science. In Year 6, there is streaming. Regular testing and examination mean that a child’s position in sets and streams can be reviewed easily.

Second, the school day is a long one. It allows time to take in much beyond formal schooling. Not just the clubs and sports (at least 12 of which go on each day) but also to allow for supervised homework. Supervision means no cheating or “help” by parents; it also means a quiet environment where professional help is available if needed.

The school becomes a centre then, not just for academic learning but also for consolidation and for pleasant experiences such as stamp-collecting, table tennis or producing the school’s very own “underground magazine”, Student Voice. Teachers understand that their employment includes the running of at least one hobby club a week.

R egular visits by speakers from all walks of life help to develop the children’s ideas about life outside and their personal goals. Perhaps most importantly, the school has a comprehensive pastoral care system. Each child is allocated to a vertically grouped set of 25 pupils. These sets, with the kind of names beloved by satirists on Private Eye (Arco, Bankers etc) are like houses for intra-school competition. There is a half-hour set meeting every Saturday morning and a long pastoral care staff meeting every week, separate from the weekly academic meeting. Children carry with them their blue set book in which teachers make comments for parents or each other and where marks for achievement, industry (effort) and behaviour are noted. These marks are also put up on noticeboards.

There are, says Mr Davies Jones, few rules, apart from “not doing anything anti-social or dangerous”; there are few sanctions, but there is a close system of reporting to parents and staff. Information can range from “He keeps forgetting his gym shoes” to “She needs to work harder on her long division this week.” In addition, there are termly written reports and face-to-face meetings once a year. Children in Years 3, 4 and 5 have informal open mornings once a term where pupils bring their parents along to see their work and meet the teachers.

The ethos and identity of the school is developed not so much through external badges such as the colourful uniform - “It’s important as a unifying marker, ” says Pam Duffill, head of marketing, “but it’s also important that there is a choice of colours within it” - but through this careful structure. Daily assemblies on a weekly theme in chapel or gym, a monthly newsletter from the headteacher celebrating achievements, a rotating system of head boys and girls with “specials” (prefects) who have extra responsibility: it is a system which involves everybody, all the time.

Perhaps the biggest marker of this attentiveness is that all the teachers, including the head, always eat with the children and talk to them over lunch. “It’s the best way to find out how they feel,” says Mr Davies Jones, simply. That is something that doesn’t cost a penny.