The Austrian Institute of Technology, within its research field Sustainable Building Concepts, is working on the next generation of buildings, aiming towards net energy positive buildings. This includes grid integration (Building2Grid project), consumer interaction (Consumer2Grid project), and smart power grids (DGDemonet project). Our research relies on application of optimized building and system simulations (Next generation building simulation and modeling tool) and power-hardware-in-the-loop (PHIL) simulation (SimTech Lab). We will talk about our R&D and expertise in designing and running highly efficient office buildings like EnergyBase (http://energybase.at/eng/index.php). Additionally, we will report on a LEED evaluation project (Desert Learning Center, Al Ain, United Arab Emirates) and present our new project, an energy-positive concept building (FutureBase, Vienna, Austria).