Keep your bills for the playroom. While you can't deduct the cost of the actual room itself you can deduct the furniture, toys, decorations, special things you put in there. Some will say you can deduct the wood and materials for the room but when you sell your home the playroom will be considered a capital asset and taxed so better to just build the room as part of an upgrade to your home and then claim what goes in the room. Also anything you already have like high chairs you will use in the business you can sell to the business and claim the equivalent of what it would have cost if you had bought the item used such as at a garage sale.