Kelley, the type of property can influence which type of measurement is used. It is also a function of the local market. For example, in our market the size of a residential unit is quoted as the area found inside the unit. Some managers may also include the size of an individual patio. For office space it is common to include the enclosed common areas. In that instance you can have a unit with 1,000 square feet that can be used exclusively by tenant, and another 1,500 square feet of common area that can be used by other tenants too (e.g. lobby, hallways, restrooms, etc.) The additional SF is sometimes expressed as a "load factor". BOMA has some good descriptions on how to measure office buildings. Retail buildings are often measured based on how much space is used exclusively by the tenant. However, some buildings with interior common areas may include common area square feet too.
Jul 24, 2012