@chuckjim
1. The cost basis is whatever you paid out of pocket to build the house. You can include materials, labor, permits, inspections, and other out of pocket costs, but not the value of your own labor.
Because you rebuilt the house after the fire using the insurance settlement, you ignore both the fire damage and the settlement, and the basis remains whatever you paid in 1999.
2. You need to determine a fair market value for the land, based on local market conditions. We can't tell you if any arbitrary amount is correct or not. If you don't know, you might consult a real estate professional or the local tax assessors office.
3. Depreciation starts whenever you place the property in service as a rental (for business). The age of the property or how long it was used for personal purposes is ignored.
