Interesting discussion--but think you need to keep a couple of things in your research: what are the zoning restrictions in your community--sometimes a shed is allowed only without utilities, heat, etc? Would an addition to your home be cost effective in your neighborhood--basically would an addition large enough for a long arm and other sewing be so expensive and not be recouped in a home sale? Would you have to update the rest of the house's electrical if you add a room? Is your lot large enough to meet the requirements of an addition? Or a "she-shed"? Obviously with a shed, you would have to have electricity--what about plumbing? It does sound like you need to make some changes due to the stairs and falls--that is a no-go for sure! I sew in my daughter's former bedroom where I've moved out furniture, added laminate flooring and it's mine! And the long arm is located in the finished basement which is shared as a rec room that gets little "rec" since kids left home! Nice thing about both is that both levels have a bathroom and storage. My thoughts are that if/when my knees really do quit (I've replaced both knees once already)I'll go the route of chair lifts. The other nice thing about the basement is it's a walk out so I can walk outside to get to it if needed.