As Lisa said, it is added as a separate asset, as an "Improvement".


However, a few things about your post concern me.

First, you said you use the Home Office 80% of the time as a self employed business.  What about the other 20%?  Personal?  As a W-2 employee where your employer REQUIRES you to work out of your Home Office?  Something else?

Second, the entire renovation does not get entered.  Only the portion that affects the Home Office.  So remodeling your kitchen would not be added in.  Adding a roof, furnace, or siding would because it affects the Home Office.  For any direct renovation to the Home Office itself, you would add a third asset that is 100% business use.

all valid concerns, I wasn't going to open a can of worms though...just answered the question!  😃

Apparently the OP may realize there are problems, as she has now deleted the question.

thanks lisa995. first time posting a question, didn't realize it would open a can of worms