My shop is 12 x 27, shed roof 8 one side, 10 on the other, built on a cement slab, T12 tubes for lighting end to end on center of ceiling, insulated, but at present not heated. Size was limited by space available, but more space than I ever had in the past. Would I like more space, sure, but I suppose it fits my age and energy level. In the ideal world it would be nice to have several such buildings, one for building, one for finishing, one to store mostly complete projects, one for lumber and all those scraps too good to throw away, yes it’s nice to dream, but if a fellow had space to add portable (or smaller) buildings as his dreams and projects grew that might be a practical solution