Get your taxes done using TurboTax

If you are using the Actual Expenses method instead of Simplified Deduction for your Home Office, you will set your Home up as an Asset and enter your Cost Basis for Home/Land. 

At the end of the Home Office Section, you will see a Home Office Summary, (screenshot) where you can Edit your Home Office Asset. 

The calculations show on the Form 8829 Asset Entry Worksheet (screenshot).