HelloCustomer Thank you for coming to Just Answer and allowing us to help you with your tax question. If you are running a computer repair business out of a portable building used as the location for your business, the cost of the building is a legitimate business expense on your Schedule C. If you purchase the building, you will have to depreciate the building cost, probably as nonresidential real property with a useful life of 39 years. This means that you will be able to deduct the entire cost of the building at roughly 1/39th of the cost per year. If you go to www.irs.gov , publication 946 explains how depreciation works and how to calculate the amount to deduct each year. If you can get a statement from the manufacturer that your building is not designed to have a useful life nearly as long as 39 years (such as a Bully Barn only designed to last ten years or so), then you can try to depreciate the building as 7-year property that doesn't fit into any existing class and you can deduct the cost over 7 years. This is a more risky strategy, since the IRS may choose not to accept the manufacturer's statement and may disallow the additional depreciation. If you rent the building rather than buying, then you can deduct the entire amount of the rent on your Schedule C each year.
Also, if the building is only used for the business, then you can deduct the cost of any utilities supplied to it, like heat, water, sewage, fixed telephone line, etc. on your Schedule C each year.
I hope this answers your questions. Please let me know if you need any further information.