The three types of depreciation INCLUDE physical deterioration, external obsolescence, and:

Non-conforming value typically refers to properties that do not meet zoning or regulatory standards, which may affect their ability to be utilized effectively. While related to valuation, it is not classified as a type of depreciation but rather a characteristic that can impact property value under specific circumstances.

Regression pertains to the principle that a property's value may decrease due to the presence of less desirable properties nearby. This concept relates to external factors influencing value, rather than being a distinct type of depreciation like physical deterioration or functional obsolescence.

Progressive deterioration is not a standard term in the context of depreciation types; instead, it may imply a gradual decline in a property's condition. Such language does not encapsulate the established categories of depreciation, which focus specifically on physical, external, and functional factors.