Taxpayer jointly owns home w/ a non-spouse. Office space is used exclusively by taxpayer. For total area, should the remaining part of the home square footage be divided by 50% and then add the office space square footage? Dividing any utilities in 1/2 assuming that is how they paid.
Is there a better way to determine percentage of office space versus the one proposed above? They are an unmarried couple. Perhaps just treat it as you would for a married couple?