Capital improvements made to a principal residence are not tax deductible. Instead, they are added to the basis of the home (usually what you paid for it). This increased basis serves to reduce the amount of gain that results when the home is sold. However, certain energy-related improvement may entitle you to a tax credit now.
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).