As others have mentioned, make sure the place is well insulated. When I built my shop, I used 6 inch walls so I could get them to R-19. No windows on the West, North or East walls. The only windows are on the South wall, and the space between windows have hot air solar panels on them. The solar panels keep the shop at 50 degrees most of the time in the dead of winter, 60 degrees in the spring and fall. I have a back up wood stove in case I want things a little warmer, but don't use it much unless it is cloudy outside. Half my shop is for wood working, so the wood stove is where I get rid of my wood scraps. I live in Wyoming, so we have plenty of cold nights at this high elevation, but then we have plenty of sunshine for solar also.
Steve
Steve