Here's a good explanation as to why the condo has no land value. Scroll down to Paul Cuputo's comment. "A condo is considered an air-lot".
https://www.biggerpockets.com/forums/51/topics/420631-rental-condo-100-of-value-depreciable
In your case, the fact that the town does not assess any land value supports taking full depreciation, as the tax assessment is the primary method of allocating land. In your case, it's 0.
