What principle states that properties with greater similarity in an area better maintain their value?

The principle that suggests properties with greater similarity in an area better maintain their value is rooted in the concept of conformity within appraisal theory. When properties are similar, meaning they share comparable characteristics such as size, style, quality, and use, they tend to attract similar types of buyers and maintain a more stable market value. This is especially important in real estate where the neighborhood plays a significant role in value determination.

In a neighborhood where the homes are similar, for example, the value of each home is influenced by the others. If one home improves significantly, it can uplift the surrounding properties' values as well, demonstrating how conformity plays a vital role in maintaining property values.

This differs from the other principles listed. The principle of contribution refers to how much a specific improvement can add to the overall value of the property, constructive notice relates to the legal presumption that individuals have knowledge of public records, and consideration refers to the value exchanged in a contract. Therefore, the correct choice highlights the importance of property similarity in preserving value through the principle of conformity.