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 business loss that exceeds current income may be carried back against income of prior years and carried forward as a deduction from future income until eliminated.