Any improvements you pay for that you make to real propery—that is to say, land you own and anything that is permanently attached to or part of the land—adds to your cost basis. It is not a tax deduction when you make the improvement, but it may reduce your capital gains when you sell.
there might be additional state tax benefits for environmental improvements to your land, but there are no special federal tax deductions or credits. You would have to review the state program module carefully, or ask a local tax preparation expert for advice on your state tax policy. Note that if you do receive a deduction or credit at the state level, you have to treat that as a reduction in the cost basis adjustment when figuring the capital gains calculation.
