It is asking for the adjusted basis at the time you were placing the home office into use. You will need to separate the land value and the building value for depreciation purposes.
The class life of a home office used for a business is considered non-residential use property with class life of 39 years.
For additional information, please refer to IRS publication 946:
Do I have to do the depreciation and deduction part?
I tried skipping that part, but TurboTax would go back to that page.
The reason I ask is because the home office is also used for personal purposes, and IRS Pub #587 says you can't deduct this if you use your home office space also for personal use.
The reason I ask is because the home office is also used for personal purposes
Then you don't qualify to claim a home office. Period.
The program asks two questions pertaining to your use of the space being claimed as a home office. I've paraphrased the questions here.
- Percentage of time you use this home office for business - You may only be in that home office 1 hour a day conducting business. But if for that one hour each day you occupy it, if it's only for business, then it's 100%. If you use that office or space for anything else, then it's not used 100% for business and you do not qualify to claim the home office.
- Percentage of business conducted in the home office - This will usually be less than 100%. For example, in my computer business a majority of my business is conducted "on site" at the client's location. I'm only in the home office conducting business about 30% of the time. When the office is occupied, I make/receive business phone calls, do invoices, order supplies, perform book keeping tasks, schedule jobs, etc.