I do indeedy
Mine is huge, it's 12x20ft or something like that, can't remember now and it did cost a lot to do but you can go smaller to reduce the costs. I didn't want it so big but hubby insisted I'd fill the space and he was right :o I can't believe how I've filled it and could actually do with a bit more, so be careful you don't go too small.
Bare in mind though that if you are working from home in a cabin/summerhouse, you ideally need running water to it and in mine we have a toilet, so that clients don't need to come through the house to use ours.
Also, to ensure it was warm in the winter, we had it all boarded out and insulated, then plastered, otherwise it can be extremely cold in there. Even with doing all this, it's freezing in there until my heaters have been on for an hour or so.
But I love it and quite often go in there to play when I haven't any clients, I just love being in there so much, I'm very lucky.
There's still a bit of finishing off to do like painting woodwork, door handle on bathroom door etc but I'm still using it and clients aren't bothered in the slightest and absolutely love it in there too :green: Here's a few pics
(Looks slightly different to the pictures now as I've got my new Shellac Rack on the wall where the poster is and my glitters are on top of my desk where the shellac is in this picture)