not heard of that (although as you say it's local and broadly sounds a good idea) - although aware that some leasehold flats it is a condition of the lease that you can't rent the whole place out
and depends just what 'occupying' means - working away for a short time may not be an issue if you keep it as your main address (e.g. stay registered with local GP and so on)
a while ago i had a lodger here, albeit only during the week (and not always all that much) and enquired with the council tax people as i didn't want to keep quiet and risk getting done - they said if he was still registered with GP and that sort of thing at his home address, it didn't count.
broadly, i'd agree.
i thought 90 quid a year service charge (which basically means they have the grass cut badly a couple of times a year and send me a bill every year) was a bit much until i saw the service charges on some private flats...
some councils are either completely crap at maintenance or regard leaseholders as a cash cow (and in some cases both) - mine's fairly reasonable.
there appears to be a
council leaseholders' forum in sheffield (think the one here has given up) which is more than you get with most private leaseholds.