The new, 6.0 version of SIMBAD (SIMulator of Building And Devices), the energy efficiency oriented library for the construction of dynamic building models in the Matlab/Simulink environment, is currently developed at CSTB. This simulation tool provides the necessary components to simulate dynamically at a small time scale (less than a minute), or emulate in real-time, complete buildings along with occupants and systems, as well as to develop and evaluate building control strategies. The two main evolutions in this new version of SIMBAD are the following: the rewriting of many essential models in an object-oriented fashion using the C++ programming language, and the creation of a C++ simulation platform including algebra, numerical analysis and thermodynamics tools. Every single modeling block can then be included in Matlab/Simulink through an S-function. It makes simulations much faster, and lighter in terms of memory load than with the Simulink-only model blocks from previous SIMBAD versions. This new version brings a centralized description of all component parameters into a single XML file, making easier the edition and translation (in particular from Building Information Models) of modeling data. The choice of the C++ programming language also makes possible the communication with external libraries for visualization and communication with acquisition cards. In the future, the concomitant use of the simulation platform and model blocks will enable the linking of every SIMBAD component or group of components with visual BIM edition tools as an energy efficiency simulation plug-in, as well as the creation and diffusion of easy to use, dedicated standalone tools.