ENERGY WARDEN (EW) addresses the optimisation of renewable energy technology (RET) deployment in the building domain. EW will develop and market the following products:SIMULATOR (EW-S): A simulator and modelling tool, including dynamic models for energy producing, storing and using units that may provide decision aid when designing or retrofitting energy infrastructures at the building domain. Important to highlight is that the simulator will be run in a short and a long term time frame; that of 1-4 days and that of a year. The first time-frame will be driven by meteorological forecast data, which have a large level of confidence for this time-frame. The first time frame delivers set points to the EW Controller, whereas the more long term one is more suitable for assessing RET investment scenaria.CONTROLLER (EW-C): The controller will be based on an expert system/ neural network approach and will provide real time control of the RET infrastructure. The real time controller will manage how energy is allocated between uses, stores, and possibilities to be fed back to the energy network. The EW-C may also unveil energy use trends, particularly useful for the simulator. In this way, the EW-S and the EW-C form a closed loop. The EW-C will include a data collection module, low cost hardware including sensors and data loggers/ transmitters, which will be deployed at the building over a period of time and facilitate the collection of data. It is emphasized that emerging wireless protocols will be a key aspect of this data collection, as such systems are particularly important in the case of energy retrofit action, where wired sensors may be impossible or costly to install.POLICY (EW-P): A higher level functionality will support policy conformance and emission trading, allowing to monitor the building performance, old and new, against existing policies or standards, including the EU directive on building energy as well as supporting the capability for use in emission trading calculations.EW will be an open, standard compliant, system, able to support many new, upcoming, supply/ store/ use options that are constantly entering the market.