# Combined MvdXML and Semantic Technologies for Green Construction Code Checking
## 4 Methodology of Green Construction Code Checking  
Each method has its own characteristics and should be used according to requirements of the green construction specification. XML and mvdXML data can be transformed into OWL/RDF description language as the rule base of ontology (see Figure 1), which allows mvdXML and semantic technologies to be integrated for code checking. Based on this concept, an approach combining mvdXML and semantic technologies for code checking of green construction is introduced below (see Figure 2).  
It is necessary to follow some specific steps for high efficiency and performance of code checking.  
1. Data source. The green construction standard is selected as one data source, which can be converted into XSLT (Extensible Stylesheet Language Transformations)/XML based on rule expression and classification of clauses. Model information in IFC and/or MVD is selected as another data source, which can be expressed in Excel and transformed to mvdXML form using the mvdXML rule transformer by data preprocessing [44]. The missing information for green construction code checking can be added in mvdXML using IfcDoc.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Classification of Clauses** & **Types of Inspection** & **Example Clauses in GB/T50905-2014** \\ \hline \multirow{3}{*}{Class 1} & Code checking based on simple & \&3.2.1 Building material storage site \\  & defined attribute value in IFC & should be no more than 500 km from \\  & schema. & construction site. \\ \hline \multirow{3}{*}{Class 2} & Code checking based on the & \&4.0.5 A database of building \\  & extension of IFC entities. & materials should be established and a \\  & & building material with good green \\  & & performance should be adopted. \\ \hline \multirow{3}{*}{Class 3} & Code checking based on simple & \&9.2.4 Cast-in-place concrete raw \\  & conceptual reasoning & materials should be mixed in \\  & & construction site. \\ \hline \multirow{3}{*}{Class 4} & Code checking based on & \&9.2.7 When spraying materials on \\  & construction condition reasoning & site, the ambient temperature should \\ \cline{1-1}  & & be 10–40 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table}
Table 1: Classification of various kinds of clauses in GB/T50905-2014.  
2. Knowledge base. The conceptual model ontology, work item ontology, and construction condition ontology for green construction are built in this part. The ontologies in the knowledge base consist of facts and axioms.
3. Rule base. The rule base includes customized rules that are used in conjunction with the content in the knowledge base for the JESS inference. The customized rules are based on the model information in IFC and/or MVD. The rules in this study were established in Protege 3.4, and the grammar format was based on RDF [45].
4. JESS inference. The facts and the rule base are matched to obtain inference results through JESS inference engine. After the transformation from the JESS rule language to RDF/OWL, the inferred facts can be used to update the knowledge base.
5. Query. To meet the need of query function, the result needs to be transformed into a computer-readable format. The converted data representation is in the form of a triplet, which consists of resources, attributes, and values that can be represented by the concept and relationship of ontology and can be queried by SQWRL or SWRL. Finally, the report of code checking for green construction can be produced using Hypertext Markup Language (HTML).  
In addition, the IFC model can be checked by the mvdXML ruleset and a BCF report is generated using a BCF generator; then, the issues can be shown in Revit using BCFier with a BIM view [46].  
Figure 1: Transform between XML/mvdXML and OWL/RDF data.