This week, our huge if unsightly sports dome has been decommissioned and laid with 500 square metres of carpet to protect its floor. Yesterday, eight sixth-formers spent the evening hauling 300 exam desks and setting them out in the precise formation required by the awarding bodies. The sadistic architect of a factory farm would be proud of us. We roped the students in for pound;6 an hour because the sheer scale of the operation would have overwhelmed our three caretakers.

We have trained a team of 20 invigilators - a mix of genial but dedicated locals with expanses of time on their hands. They will be paid pound;7.46 an hour to shuffle unobtrusively around the exam hall for hour after slow-moving hour. Our exam team (it’s no longer a job one person can do while juggling a half timetable as a maths teacher) have checked the paperwork for 295 different exam papers and double-checked 7,300 candidate entries.

On our heaviest exam days - which my natural pessimism tells me will prove to be the hottest of the summer - we will still be short by eight invigilators. Under the workforce agreement, we can’t use teachers, so some reluctant combination of administrators, cover supervisors, teaching assistants and the leadership team will have to step into the breach.

We like to boast that we’re not an exam factory, not the kind of school that picks its courses because they deliver a volley of results that will nudge us up the performance tables. We think the other stuff we do - drama, music, sport, debating, the Duke of Edinburgh Award, the charity work - matters just as much. We are truly comprehensive, with 1,340 students aged 14 to 19. Between now and the end of term, every one of them will sit some form of public examination.

The cost of this? We have budgeted pound;113,000 for the exam fees alone. But the carpets, labour charges, invigilators, administrators, and the lost income from community sports bookings - all of these mean the real cost is significantly higher. Let’s not contemplate how many textbooks, teaching assistants or computers it could fund, or how it might help us pay for the student college placements we’re having to scrap because of budget cuts.

“Not an exam factory,” indeed. How hollow and self-deluding that must sound to the students we’re chasing into yet another session of lunchtime and after-school revision classes.

We had assumed that the reduction in A-level exam modules from six to four might lead the exam boards to reduce their costs. Not a bit of it. Modules that cost pound;12.50 per candidate are going to increase to pound;16.80, with teachers, of course, still doing the assessment of coursework, travelling to exam moderation and training sessions, and us paying the costs of all the administration.

And the new GCSE specifications will mean even more modular exams. We already anticipate closing down classrooms and sports halls, hiring more invigilators, laying more carpet, abandoning indoor sports and the gradual leaching of midsummer madness into chillier seasons.

Gordon Brown may ascribe Labour’s drubbing in last week’s local elections to the financial downturn. But he can be assured that there’s one bit of Britain’s economy that’s positively thriving - the burgeoning, self-propagating frenzy of the exam industry. It is a many-headed monster that dominates the school year, distracts us from teaching and has spawned a great army of bureaucrats far removed from classroom realities.

But at least the carpet-fitters are happy.

Geoff Barton, Headteacher of King Edward VI School, Bury St Edmunds, Suffolk.