Gross Square Feet (GSF) is the total amount of square footage of a building. This includes all spaces within the outside faces of the exterior walls. Examples included in this measurement are common areas, maintenance and operation areas, balconies, attics, walkways, corridors, and any other parts of a building that are accessible within a building. This means that GSF does not include parking lots and other open areas like pools and unexcavated basements. Some construction budgets have costs that are estimated based on the gross square feet of the building.
Net Square Feet (NSF) is another popular metric in measuring real estate properties. NSF is defined by the accessible space of a building and includes most space within the inside finished surface walls of a building. Calculating the NSF is more difficult to calculate than GSF, but it is valuable for tenants to know how much space is available for their use. Net Square Feet is made up of Assignable Square Feet and Non-Assignable Square Feet.
In Quebec, a developer is allowed up to 10% ‘variance’ between the ‘gross’ and the ‘net’ square footage. The most important thing you need to know in all of this is that it is NOT legal for you to re-sell on the basis of the ‘gross’ square footage. You MUST declare the net square footage.