Office buildings are usually classified into Class A, Class B, or Class C, although there is no definitive formula. Standards vary by market to describe the overall quality of the building. Generally, Class A represents the newest and highest quality buildings in their market, with convenient locations and are professionally managed. Class B are a little older, but still have good management and tenants. Class C is the lowest classification. These buildings are usually older, located in less desirable areas, and may need renovation.