The Directive 2002/91/EC of the European Parliament requires member states to calculate the energy performance of (new and large existing) buildings. As a consequence the software industry developed tools that allow the calculation of a building’s energy efficiency based on its geometry, materials, windows, doors and heating/cooling configurations. However, existing tools provide good results in calculating the energy level of a given architecture but fail to support the user in the subsequent step – the identification of a strategy on how to improve the building’s energy performance level (considering financial, legal and individual requirements and constraints). The manual identification of the optimal building configuration is not only tedious but very costly for the user and, therefore, sets a major entry threshold for improving energy efficiency. The overall goal of this research studio is to develop a prototype that enables users to efficiently identify potential building configurations with regard to (i) environmental impact, (ii) energy consumption for operating the building, (iii) energy used at the production and distribution of building components, (iv) financial constraints, (v) building component compatibility, and (vi) legal requirements. The research project will use salient basic research approaches to develop the following components: (i) AEC (architecture, engineering, and construction) ontology: provides cost, energy efficiency, and environmental impact data on building components, such as windows, bricks and insulation. The ontology allows for formally specifying the compatibility of the products (e.g., a certain window type can only be combined with a specific wall type), (ii) legislation ontology: to automatically interpret relevant legislation at the building configuration computation, we model legal requirements (e.g., minimum window size and required insulation layers) machine-readable in an ontology, (iii) semantic transformation modules: convert traditional product catalogs, relevant standards and legislation, and building plans into an ontological structure as defined in (i) and (ii), (iv) AEC reasoning module: based on the requirements (user-specific, legal, and technical), the reasoning module extracts potential building configurations that fulfill the requirements from the ontologies , and (v) interactive decision support mechanisms: enable users to further restrict potential building configurations according to their individual preferences (e.g. regarding financial constraints and energy efficiency) in an interactive way. The project results (i) suggest the users efficient strategies on how to close the gap between the status quo and a better energy performance level, (ii) consider the users’ individual preferences (such as initial costs, running costs, environmental friendliness, etc.) and (iii) identify the optimal set of specific construction products to implement the selected strategy.