In order to add the cost of capital improvements (an addition on the home, a new furnace or roof) to your basis, you need documentation. If you don’t have receipts for your expenditures, try getting what you need in another way. For example, contact the contractor or vendor you used for a sprinkler system, new carpeting, or any other improvement and ask for a copy of a paid receipt.
Writing off the cost of depreciable property over a period of years, usually its class life or recovery period specified in the tax law.