Many commercial environmental analysis tools support the evaluation of a building model based on parameters assigned in the design process. However interoperability issues between different data exchange formats hinder the iteration between design and analysis. Because the engineering calculations involved in analysis and evaluation are not integrated with architectural design parameters, evaluation takes place after the design is already defined, and analysis in real-time is not possible. In this project we integrate architectural design and engineering constraints to support design evolution and decision making by using a set of performance objectives. We propose a framework for coupling performance knowledge with generative synthesis to address multidisciplinary design challenges in the Architecture, Engineering, and Construction (AEC) industry. We develop a tool to support design evaluation based on performance criteria: energy consumption, comfort, and cost. Results show real-time information exchange as links between architectural geometry and engineering parameters. The outcomes of this research describe workflows and methods to evaluate alternative design proposals at early stages in real time.