ABSTRACT
Rule checker software has achieved increased inter-
est and is often regarded as one of the big benefits
by using BIM/IFC based software in the design
process (SmartMarket Report, 2009). Clash detec-
tion and check of doublets is one of the most used
examples. This is of course good examples on the
power of these software tools, but the rules are in
principle very easy on purely based on Boolean
expressions. These rules can also be implemented
parametric, allowing the user to change the “rule”
by changing the min/max values the components
are checked against. Borrmann and Rank (2008)
have used 3D Spatial Query Language on BIM
models to check out relationships. The operator
comprise of; metric (distance, closerThan, farther-
Than etc.), directional (above, below, northOf etc.)
and topological (touch, within, contains etc.) oper-
ators. Despite this can be complicated to perform,
the rules itself are simple.
