Accountant is using a weird depreciation method, is he right?

[Jack B.]

He tells me the appraised amount of the structure (not including land, just the house) divided by 27.5 is NOT the depreciation method.

He said the purchase price is my  basis and that...

Depreciable basis = basis * land value percentage.

Land value % = appraised land value when the rental was put into service divided by appraised total value when put into service. 

Is he right??