<prompt> Human: Right now my office is a spare bedroom. By rooms it is 18 of the house and I can deduct 18th of my household expenses as this part of my house is a business expense.If we move homes and buy one that has a large percentage of commercial or office type space with a small integrated living space so maybe 75 office . Could I then deduct 75 of my household expenses?  <response>: Sure, if you plan to meet the restrictive requirements of the IRS.Exclusive use, Regular use, Principal place of Business. Theres a few others, and theres a handy flowchart. 