Who said it has to be a lining room. The space is suppose to be a living room only if you spend the majority of your time there. Now if you spend the majority of your time in the 'sewing room' that should be your living room. So in other words go for it. Your living space should be what and where you spend the majority of your time living. For you, me and many others that is our sewing pace. Go for it my dear.