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.
Debt secured by a principal residence or second home to the extent of the excess of fair market value over acquisition debt. An interest deduction is generally allowed for home equity debt up to $100,000 ($50,000 if married filing separately).