The thesis deals with the behaviour, with respect to EMC (Electro Magnetic Compatibility), of cabling and wiring in buildings and installations. Measurement and calculation methods are developed and applied to cabling in a large scale installation as well as to individual cables. Besides, the location and interconnection of conductors, especially concrete reinforcement, in a building is investigated. Finally a procedure is developed that is used to deal with EMC issues in a large installation in a structured way.