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.
A capital loss that is not deductible because it exceeds the annual $3,000 capital loss ceiling. A carryover loss may be deducted from capital gains of later years plus up to $3,000 of ordinary income.