Both systems are designed to provide a quality rating for buildings, which indicates the competitiveness of each building to attract similar types of tenants. Various factors are considered in assigning a rating. These include the age of the building, rental rates, location and accessibility, architectural features, building finishes and amenities, operating efficiencies, quality of building systems (HVAC, elevators, etc.) and the general market perception of the property.

The Metropolitan system is used within a particular market area, while the International system is used by those who own properties across numerous markets.

According to the Building Owners and Managers Association (BOMA), the definitions of the ratings for each system are:

METROPOLITAN

Class A
Most prestigious buildings competing for premier office users with rents above average for the area. Buildings have high quality standard finishes, state of the art systems, exceptional accessibility and a definite market presence.

Class B
Buildings competing for a wide range of users with rents in the average range for the area. Building finishes are fair to good for the area and the various buildings systems are adequate. The building does not compete with Class A at the same rental rates.

Class C
Buildings competing for tenants requiring functional space at rents below the average for the area.

INTERNATIONAL

Investment
Investment quality properties are those that are unique in their location in the best metropolitan markets in the world. They have a high quality of design and construction. They attract high quality tenants and have best in class management. These properties are leaders not only within their given metropolitan area, but also with the international investment community.

Institutional
Institutional grade properties are those of sufficient size and stature that they attract large national and international investors. They have solid design and construction quality, and are typically large properties. Although they may be located in a secondary market, they almost always have a very stable tenant roster.

Speculative
Speculative properties typically mirror popular design conventions at the time they were built, but without the use of high quality materials and finishes. Their design tends to support functionality as opposed to aesthetics. To attract national or international attention, these properties must be large. They are typically occupied by numerous tenants.