The 4 Different Zone Stamp Areas in Archicad Explained

When I started to look into zone stamps in Archicad I got really confused by the different area calculations. And I still sometimes forget the subtleties. There are some guides online, but I wanted a quick overview of the just these four possibilities.

Area Calculation Example

I have set up a very simple example with a room bounded by a composite walls with the reference line on the outside edge. Additionally there are 3 columns with the option Reduce Zone Area Only in the zone.

1. Measured Area – This gives the area of the full extend of the zone stamp. If you are using Construction Method: Reference Line, then this includes the area of the bounding walls. In the Screenshot I’m using the option Gross to display the stamp also over the bounding walls. Using Net here would give the same measured area but the stamp would only display up until the inner edges of the bounding walls.
2. Measured Net Area – This gives the area of the stamp excluding the area of the bounding walls.
   Typically I use Construction Method: Inner Edge. With that setting, there would be no difference between Measured Area and Measured Net Area.
3. Reduced Area – This area is closely related to the Area Subtraction fields. Here the areas of Walls, Curtain Walls, Columns, Fills (if set to Reduce Zone Area Only or Subtract from Zone) and Low Ceilings are calculated and then subtracted from the Measured Net Area.
   So Reduced Area = Measured Net Area – Σ Area Subtractions.
   You can fine tune the area subtractions in the Project Preferences: Zones.

4. Calculated Area – This is the simplest step. It just reduces the Reduced Area further by the value specified in the Reduce by field.
   So in the example above we get: 9.23m² – 0.05 * 9.23m² = 8.77m²

Notes and References

• Don’t forget to use Design -> Update Zones… if you change anything to update the calculations.
• You can find a lot more details in this insightful Community Post by Vimal Kumar from Graphisoft.