Perhaps an age allowance that your accountant forgot to claim?
Or perhaps the tax people haven't a clue?
My greenhouse is only 6' by 8' as well, but that's enough for a few tomato plants.
My Dad tried growing those outside one year, but hardly any ripened. Just doesn't get warm enough up here usually.
The home grown ones taste nicer than the bought ones. That's my main reason.
I'm only going to put a few things in the flower bed, just for the sake of growing a few really. I'm not going to dig up the lawn or anything.
A cloudy, but mild day here.
I've reduced the amount of time the heating is on for.
It's now on for 2 hours in the morning, and from 5pm.
I'll reduce the time further as it gets milder.