I am no expert on these matters, but I would raise the issue with your line manager or the Head. Surely, you should be compensated with some extra time to produce reports for SMT. Nor should you be attending extra meetings if you do not want to - will they pay you extra for that time?. Good management should realise this. It does not sound very fair to me. They are giving you an increased workload and adding to your directed time - surely beyond the duties of a teacher on the main scale of pay without TLR payments. Are you UPS? Maybe they could argue it that way? HODs normally get extra time to deal with their duties - in my school we get one extra non contact period (not PPA) a week. Yes, we have extra meetings and have many reports to write, but then we receive extra pay. If you do not get an agreeable response or come to some compromise, I would be tempted to consult your union rep (if you belong to a union) for further advice.