Compliance checking on building models with the Gherkin language and Continuous Integration

In this paper we document our approach on applying Behaviour-Driven Development (BDD) and Continuous Integration (CI) from the software industry to the construction sector. We have provided a freely available open software toolset for the application of rules in the Gherkin syntax to an IFC building model. A prominent aspect of BDD and contrary to mvdXML, the formalization of rules in plain-test human-readable scenarios provides a basis for collaborative formalization of rules among stakeholders. At the same time our approach includes imperative program code that is fully extensible to incorporate for example external data sources and geometrical reasoning. Runnings test on every model revision (the CI concept) as opposed to, for example, upon model delivery ensures a proactive approach to compliance. Reusing existing open source frameworks allowed us to build a comprehensive solution for continuous and automated model checking, visualization and reporting in several hundred lines of program code.