Report this as sale of an investment item. Use the purchase price and the sale price to be the same. The proceeds from the sale are not taxable, but the price you received for the strip of land reduces your cost basis, which is used to calculate your capital gains when you sell the main property.
for example, suppose you purchased the house for $100,000 and you receive $2500 for the sale of the strip of land. Whenever you sell your home, you would calculate your capital gain from an adjusted cost basis of $97,500.
