Expenses to buy or build a home are never tax deductible.
If you were building a structure for business, you would take a deduction for depreciation over 27.5 (or more) years, but you also pay recapture tax when you sell.
For a personal residence, the expenses are not deductible and you don't take depreciation, but when you sell, you only pay income tax on the gain (profit; amount the property has increased in value over your original cost), instead of paying tax on he entire sales proceeds.
