So it's actually easier if you're self employed over there?
Here they assume a fixed percentage. I can claim back for council tax, electricity, gas, water, all sorts. I even get VAT off the petrol I use (and of course all my petrol is used for business and none for holidays :-))
What a waste of paperwork. I don't have an office, I have a huge open plan room which is a living room, computer room, office, and parrot aviary. God knows what your tax office would make of that. They'd probably want to see evidence of the parrots making money by breeding.