I had to give that one some thought. I stand during the cutting, gluing and framing but after that I sit and make up and install controls, linkages, servo mounts, get the engine set up, sanding, onandonandon. Then I sit and finish sand and start covering, from the chairs. So, about three days standing then weeks of sitting?
I have two computer chairs and A smooth floor so I can scoot around A lot without having to get up too often.