The guideline VDI 3805 Part 1 describes fundamental rules for the exchange of product data in the computer-aided process of planning technical building services. It furthermore specifies the general product data model, the associated data record structure and the description of geometry data, technical data and, if applicable, any media data. The guideline compiles extensions and corrections to the series of guidelines VDI 3805, which have become necessary and have proven useful in the course of application of VDI 3805. It applies primarily to the products and components of heating, ventilation, air-conditioning and sanitary systems. However, other products can also be represented using the series of guidelines VDI 3805.