Hi! I need some advices on which FPSF design I should choose for my Workshop (20'X 30') with gable roof and a full loft upstairs. I'm building my slab on grade according to the Revised Builder’s Guide to Frost Protected Shallow Foundations ( http://www.albertasoils.com/Docs/RevisedFPSFGuide_Sept2004.pdf ) Should I build according to the unheated or the heated design considering that I will only heat the space periodically when I need to work there. I will Also live in the loft upstairs for the first winter. The unheated building technique is more appealing to me considering the simplicity of it. I live in Eastern Canada with cold and wet winters. Thanks for Helping !

IMO, a FPSF design that can also be operated unheated should be used in all heated situations.