I have itemized all the expenses and sales taxes paid for construction of a new home and TurboTax doesn't allow the deduction. Why?
Not sure what construction "expenses" you tried to use. Sales tax only affects your refund or tax due if you have enough other itemized deductions to exceed your standard deduction.
Many taxpayers are surprised because their itemized deductions are not having the same effect as they did on past tax returns. The new higher standard deduction and the elimination of certain deductions, as well as the cap on state and local taxes have had a major impact since the new tax laws went into effect beginning with 2018 returns.
Your itemized deductions have to be more than your standard deduction before you will see a change in your tax owed or tax refund. The deductions you enter do not necessarily count “dollar for dollar;” many of them are subject to meeting tough thresholds—medical expenses, for example, must meet a threshold that is pretty hard to reach. The software program uses all the IRS rules that apply to the expenses you enter, and it tells you if you have enough to use your itemized deductions or if using the standard deduction is more advantageous for you. Under the new tax laws, some deductions have been capped—there is a $10,000 limit to the itemized deductions for state, local, property and sales taxes.
Your standard deduction lowers your taxable income. It is not a refund.
2019 Standard Deduction Amounts
Single $12,200 (+ $1650 65 or older)
Married Filing Separate $12,200 (+ $1300 if 65 or older)
Married Filing Jointly $24,400 (+ $1300 for each spouse 65 or older)
Head of Household $18,350 (+ $1650 for 65 or older)
Look on line 9 of your 2019 Form 1040 to see your itemized/standard deduction amount
Most expenses associated with construction of a new home aren't deductible. This website has a good discussion about it: