ARCHICAD properties provide a rich calculation engine in their own right and should be exploited as fully as possible for quantity calculations. Even if no calculations outside properties are required, Quantities will ensure the results are allocated to the correct bill items. But there is much more you can do with Quantities – accessing parameters, IFC properties and lists of finishes/materials etc. – and properties often simply contain raw values essential for complex measurements.
Note that a calculation can include any property name you like – Quantities does not require the property to exist in order to accept the expression (refer to section 4.4.1 above). This makes it far easier to create template recipes that are applicable across a wide range of projects.
Element properties are retrieved in the following way:
element.property
Elements may have many properties, so the result is in a list (see section 4.4.6 for more detail). We can work with the value of a specific value by specifying its name and group:
element.property(“<property group name>::<property name>”)
A property group name is optional, but if there are multiple properties with the same name (which ARCHICAD permits in separate groups) Quantities will take the first one it finds. For example, to get the ‘volume per brick’ from a property called Brick volume in a group called Masonry we could write:
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With group:
Without group:element.property(“Masonry::Brick volume”)
element.property(“Brick volume”)
To ensure the property was only extracted for walls, the expression could be:
wall.property(“Brick volume”)
If the number of bricks was to be calculated based on a specific material called Masonry – Brick (assuming the brick volume accounts for mortar), the total volume of skins of that material in a wall is required (see section 4.4.8):
wall.material(“Masonry – Brick”).volume
The calculation for the total number of bricks would divide that volume by the single brick volume like so:
wall.material(“Masonry – Brick”).volume / wall.property(“Brick volume”)
When an element doesn’t fit any of the necessary criterion (not a wall, doesn’t have a skin of Masonry – Brick, doesn’t have a property called Brick Volume) the result is zero (no errors will occur, mathematical or otherwise).
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