A Taxpayer who owns an investment property that he rents out for part of the year and uses for his own personal use during the year, will be limited in the amount of business deduction he may claim for expenses incurred on said property. If the Taxpayer rented out the property during the entire year, and didn’t make any personal use of it, he would be able to deduct 100% of his costs associated with utilities, maintenance and depreciation. However, if the Taxpayer makes joint use of his property, as described above, he will be limited to a proration of his expenses for such property in accordance with the use/days of ownership.