Office, industrial and retail properties are measured in square feet. Buildings can be measured in “gross square feet” or “net square feet.” A 1987 article in the New York Times offered definitions of both terms: Gross square feet - “the sum of the areas at each floor level, including cellars, basements, mezzanines and …. Included are all stories or areas that have floor surfaces with clear standing head room (6 feet 6 inches minimum) regardless of their use.” Net square feet - “the sum of all areas within the perimeter walls of the unit measured to the inside faces of said walls and including all columns, shafts, ducts and risers whether separately enclosed or not.”

Apartments, hotels and self-storage facilities can be measured in square feet, but are more commonly measured in units or rooms. For example, an apartment complex may have 200,000 square feet, but would more commonly be described as having 1,500 units. A hotel may have 100,000 square feet, but it would be more common to identify it as having 500 rooms.

Properties are often identified not only by their address, city or state, but by the submarket in which they are located. Some submarkets are essentially neighborhoods, such as in Manhattan, which identifies such places as Chelsea, Harlem and Times Square as submarkets. Other submarkets are regions, such as Northern New Jersey or Silicon Valley, in Northern California.

The cap rate is the initial annual return that a buyer can expect on his investment. It is calculated by dividing the projected net operating income for the first year of the investment by the purchase price. If a building sells for $10 million and generates $1 million of projected net operating income, the cap rate is 10%. Investors can use cap rates to compare the returns of their real estate holdings to the performance of other types of investments, such as stocks and bonds.

For some properties, it is important to consider the initial annual return. But for other properties, it is more appropriate to consider the stabilized return – ones that are either not well leased, have leases that are about to expire or are candidates for conversion to other uses. The stabilized yield is determined by calculating a projected yield after the building’s performance has been maximized.

Properties can have various types of leases. A traditional office lease is considered a gross lease – meaning the property owner is responsible for virtually all costs related to the leased space, ranging from taxes and insurance to water and power costs. By contrast, some office tenants, and most industrial and retail tenants, pay a net lease. In such a scenario, the tenant is responsible for the costs related to the space. Depending on how many of the costs are assumed by the tenant, a lease may be considered single-net, double-net or triple-net. The charges and payments of building expenses are also known as Common Area Maintenance (CAM) expenses. In a typical net-lease, the tenant shall reimburse the landlord for all expenses related to the maintenance of the property such as cleaning, gardening, snow-removal, lobby, lights and the like. In a double-net lease, the tenant also required to cover insurances, accounting, and certain legal expenses incurred by the landlord. In a triple-net lease, the tenant is also responsible for property taxes and certain improvements of the leased property.

The difference in rates of the various types of leases can be great. An office space could conceivably be advertised as having an annual rent of $50 per square foot as a gross lease, and $35 per square foot (annually) if the lease is triple-net.

Some property owners prefer to deal only with credit tenants (see example), which have investment-grade credit ratings, as rated by a third-party agency such as Moody’s, Standard & Poor's and Fitch. Any rating above BBB-minus is considered investment grade. Properties with investment-grade tenants are often considered more valuable by investors.