I agree with the posters who mentioned A/C and Heating. Without conditioned air, your fabrics and machines would be ruined if you stored them in there. Having said that, I have a nice table in my screened porch. I often take my machine and just sew out there. So you might want to consider storing your fabric and machines indoors and just make a work area in the shed. Take your projects out for the day, then bring them back in when you are done working. Oh, and make sure the electrical service is good.