||The effective use of information technology, IT, in the building processrequires a common language of well designed classification and coding systemswith clear rules for their application. To date, building elements and spacesare the principal concepts submitted to classification for the building sector.A third concept, the interactions between building parts, elements, spaces andsystem is less considered as an area for systemizing and classification.However, neglecting the interaction problems, which could affect what will becalled the Building Intep'ty, BI, causes many negative effects during thebuilding process and operation, eg, increased cost, low quality of the finishedbuilding and uncertain and vague distribution of responsibility between anincreasing number of actors and suppliers of the building process. An analysisof the problem is presented, a few examples are given and a tentative set ofprincipal classification concepts are established. The research is still in apreliminary stage. An indication of a possible place for an implemented ITsupport system, ITSS, supporting BI aspects in the building process is given.