Deductions & credits

I should describe more,

 

We have a rental property that's been renting 12 years.

 

In 2020 we built a 2nd house on the same lot in the backyard, costing $350K. This 2nd house was not rented out in 2020 because it wasn't completed. The $350K spent, wouldn't that be a LAND IMPROVEMENT? We would like the $350k as a Depreciation.

 

Or, because the front house continued to be rented during this period, I would mark it as RENTAL REAL ESTATE?

 

Thx