Area calculation complies with the American National Standard method for measuring floor area in office buildings (ANSI/BOMA Z65.1-1996). The calculation is based on the geometries of the building components in the building information models. To get the best result the walls and spaces should be modeled carefully. Low quality modeling such as missing spaces can lead to wrong calculation results. Before areas can be reliable calculated, external walls have to be defined. This can be done by defining Gross Area Compartments in Compartmentation View (ref. Using Compartmentation). The results of the calculations are seen in the Info View, 3D View visualizations, and reports of ANSI/BOMA View.
There are two possible calculation methods, ANSI/BOMA or GSA. The used method is set in the ANSI/BOMA View Settings. All properties used in the calcualtions, and their calculation principles are listed below.
GSA BIM Area
The area calculated from the geometry of a space component by removing areas of intersecting columns and walls.This quantity is visualized in the 3D view with black text.
Usable area
The usable area is base for the all other properties. It includes the space area and bottom area of walls around itself. The amount of wall bottom area depends on the ANSI/BOMA Space Category of the space. The space category is either get from the ANSI/BOMA Space Category or it is based on the PBS Space Type. You can also set the category manually.
For Office area and Store area: area + half of the wall bottom area of walls between another Office, or Store areas. If the exterior wall contains windows, whose height is at least half of the space height, the area from space boundary to window (DOMINANT PORTION) is included.
For Building Common and Floor Common: area + wall bottom area, when a space in other side of the wall is not Vertical Penetration. If the space on the other side of the wall is also Building Common (or Floor Common), half other wall's bottom area is included.
For Vertical Penetration and PBS Specific areas: area + wall bottom area. If the space on the other side of the wall is also Vertical Penetration or PBS Specific Area, half other wall's bottom area is included.
Basic Rentable Area
Floor RU Ratio * Space Usable Area
Rentable Area
Building RU Ratio * Space Basic Rentable Area
Gross Building Area
Total area of the floor including all walls, columns and spaces. If the floor has a Gross Area Compartment (ref. Using Compartmentation), it's area is used. Otherwise, it is the sum of bottom areas of all walls, columns and spaces in the floor.
Gross Building Area w/o Parking
Parking spaces are removed from Gross Building Area. A space is a parking space, if its PBS Space Type is STP.
Measured Gross Area
Sum of usage areas of all spaces in one floor. Exterior walls are not included in this area.
Floor Vertical Penetration Area
Sum of all Vertical Penetration spaces' Usable areas in one floor.
Floor PBS Specific Area
Sum of all PBS Specific spaces' Usable areas in one floor.
Floor Usable Building Common Area
Sum of all Building Common spaces' Usable areas in one floor.
Floor Usable Floor Common Area
Sum of all Floor Common spaces' Usable areas in one floor.
Floor Usable Office Area
Sum of all Office spaces' Usable areas in one floor.
Floor Usable Store Area
Sum of all Store spaces' Usable areas in one floor.
Floor Usable Area
Floor Usable Office Area + Floor Usable Store Area + Floor Usable Building Common Area. If GSA Calculation Method is used, Floor Usable Floor Common area is also added.
Floor Rentable Area
Floor Measured Gross Area - (Floor Vertical Penetration Area + PBS Specific Area)
Floor Common Area
Floor Rentable Area - Floor Usable Area
Floor RU Ratio
Floor Rentable Area / Floor Usable Area. If GSA Calculation Method is used, value is always 1.
Building Rentable Area
Sum of all Office, Store, and Building Common spaces' Usable areas in the building. If GSA Calculation Method is used, Floor Common areas are also added.
Building Common Area
Sum of all Building Common Area space Basic Rentable areas in the building.
Building RU Ratio
Building Rentable Area / (Building Rentable Area - Building Common Area). If GSA Calculation Method is used, Sum of all floors' Usable Areas / sum of all floors' Usable Office and Usable Store areas.