1. A method of defining a region of interest in a construction document, the method comprising: accessing a stored construction document from a non-transient computer-readable memory, the construction document including a graphical representation of structures included in a building plan; displaying at least a portion of the construction document on a display; receiving an input from a user, the input identifying a point within the region of interest; identifying one or more notations in the construction document potentially indicative of boundaries near the identified point; identifying one or more notations in the construction document potentially indicative of protrusions from the boundaries near the identified point; determining whether the one or more notations potentially indicative of boundaries are part of a perimeter of the region of interest; determining whether the one or more notations potentially indicative of protrusions from the boundaries are part of the perimeter of the region of interest based on at least one criteria selected from a group consisting of size, shape, and location of the notation potentially indicative of a protrusion; defining the perimeter of the region of interest based on the notations determined to be part of the perimeter of the region of interest; and calculating, by a processor, a quantity associated with the region of interest based on the defined perimeter of the region of interest.