I use it as my office all year round. I have a small heater which I put on for an hour or so first thing which keeps me warm all day. I used to work in the spare bedroom but outgrew it. This is better as when I shut the door at night, work is finished and a minute later I am home relaxing.
Only took 4 days to go up. Had all my stuff in it and using it a couple of days later.