How much of your home will you need to turn over to your business? The space needs of a home-based business will vary widely, depending on whether you're focused on repairing cars or preparing accounts. However, there are some concepts that all businesses have in common — like the desk space and the computer where you'll handle the administrative duties. As for the rest, you need to assess what you need, compare it to what you have, and come up with whatever's left over.