For starters, your math is wrong for figuring depreciation. That's not how depreciation is figured for residential rental real estate per IRS Publication 946 at https://www.irs.gov/pub/irs-pdf/p946.pdf. Remember, when it comes to taxes, if it looks easy then you're doing it wrong. 🙂
Use the worksheet begining on page 38 and continued on page 39 of the above referenced document. For residental rental real estate (including renting part of your primary residence) use Table A-6 on page 73.
Now, when you take a property out of service, that stops depreciation. But you already know that. Here's where you need clarification.
When you place the property back in service, you must first reduce the cost basis of the *DEPRECIATED ASSETS ONLY* by the amount of depreciation you have already taken. Then using that new reduced cost basis the depreciation starts over from day one for the next 27.5 years. Keep in mind that since land is never depreciated, you will reduce the cost basis of the "STRUCTURE ONLY". The cost basis of the land will not change.
