The base area is one of the most important and, at the same time, most misleading dimensions in specter. Especially with complex geometries such as a T-shaped component, it can happen that the automatically calculated area does not correspond to the expected reality. In this article, we explain why this is the case - and how you can deal with it.
In this article, we will show you:
How Specter calculates the footprint area
Why T-shaped or complex geometries lead to deviations
Common misunderstandings that arise in this context
How to obtain more accurate results using net areas or IFC QTO values
1. Calculation logic
specter calculates the footprint area by projecting the 3D geometry of a component onto the XY plane. This creates a so-called bounding polygon that encloses all outer points of the object.
This means:
For simple components, the base area corresponds to reality.
For complex geometries, e.g., a T-shaped component, the entire shape is enclosed as a rectangle. As a result, the calculated area may be larger than the actual usable area.
Important: The base area is never too small, but either correct or too large – when viewed from above, the projection always shows everything or more, but never less.
2. Common misunderstandings
The exact contour of the component is expected, but a simplified outline surface is delivered.
Openings or indentations are not taken into account in the footprint.
In specter, the surface is primarily used for quick comparison – not for exact quantity determination.
3. What to look out for
For complex geometries, it is recommended to compare with the net area.
If there are any uncertainties, the area in the CAD program (e.g., Revit, Archicad) should be compared with the display in specter.
IFC-QTO values can also be used for precise quantity determination (if available).
4. Summary
The floor space in specter is a projected calculated outline area and may therefore differ from reality. It provides a pragmatic approximation, but does not replace exact quantity specifications. For precise calculations, supplementary values should be taken into account.