Agreement on the minimum set of default units to be defined within the project context
Based on IFC2x3
Initiator Official buildinSMART IFC2x3 CV2.0 certification programme
Effects Coordination View 2.0
Date 2010 09
The following units need to be defined as a minimum at IfcProject.UnitsInContext.
* length unit,
* plane angle unit,
* area unit,
* volume unit.
Units can either be provided as SI units using IfcSIUnit, or as derived (imperial) units using IfcComversionBasedUnit. For IfcSiUnit's the Name attribute and Prefix attribute shall agree to the units shown below. For IfcConversionBasedUnit's the Name attribute shall only have one of the string values shown below.
The following units are supported:
* length unit:
- for metric units: m, mm, cm;
- for imperial units: 'inch', 'foot'
* area unit:
- for metric units: m2, mm2, cm3;
- for imperial units: 'square inch', 'square foot'
* volume unit:
- for metric units: m3, cm3, mm3;
- for imperial units: 'cubic inch', 'cubic foot'
* plane angle unit:
- for metric units: radian; 'degree';
- for imperial units: radian; 'degree'