When my wife and I first got married, she moved into my apartment with me. I had a large L shaped work area made from joining two desks that we shared. When we bought our house and she started on a Master’s degree, I separated them in our office so she had her own and I had mine. I also went out and bought her a good leather office chair.
It turns out this was one of the best things I ever did as far as our productivity. It was amazing how much easier it was for us both to work when we had our own work area–even though the large combined work area was more than big enough for both of us.
Every person in a household needs to have their own dedicated work area and storage space. There are many things that can be shared, but a desk and some drawers are vital for each person’s productivity. If storage space is at a premium, at least get each person a small box for hanging files.
With your own dedicated space you can leave things where you want them and unfinished projects don’t have to be constantly reshuffled to make way for the next person using the area. Even if the dedicated space is small and you have a larger area of shared workspace (say the kitchen table), having some amount of space just dedicated to your needs is vital for productivity.