Organisations and / or disciplines in Building and Construction projects are usually working in their own design and engineering environments and using their own Building Information Models (BIM). The discipline models are merged into a project BIM which is mainly used to check for interferences or other flaw geometrical interface conditions. The checking is based on the skills and experience of a few individuals and usually performed as a verification afterwards. An important assumption is that many non-conformances can be avoided or at least detected easier and earlier in the project if knowledge and information between the disciplines is shared and all designers and en-gineers are working on an integral product model right in the primary process. The result will be based on the experience and skills of many collaborating individuals in different disciplines and checked during execution of the individual tasks. Knowledge, i.e. tacit knowledge, is what is in people's minds. This knowledge has to be captured and transformed into explicit knowledge so it can be used by many others. This knowledge, for example docu-mented in models, drawings or instructions, has to be integrated with the product data of the related physical objects and kept up to date. Otherwise it will be lost. Also explicit knowledge on processes and procedures has to be stored and maintained. The paper explores the relationships between the available knowledge in the project (people), the use of an integral product model in the primary process or a BIM (both repositories) and the management of all product lifecycle information (Configuration Management). Known principles like Collaborative Engineering and Concurrent Engineering are discussed as methods to share knowledge. They are also used to assure the high-est reachable level of quality, prevent failure costs and bring value added changes earlier in the project to save time and costs. Attention is paid to the role of ICT, e.g. product lifecycle management (PLM) and social media. The textbook of Dalkir 2011[2], an acknowledged guru on Knowledge Management, is used to cover the discipline of Knowledge Management. Several further references are taken from Dalkir[2]. The publication of Anumba[1] is studied for more details of Knowledge Management in Building and Construction.