With the growing complexity of energy efficient buildings, the methods of modeling and simulating such structures must account for monitoring several thousand design parameters across multiple diverse domains. As a result, modeling tools are now very specific to their respective domains and are growing more and more incongruous with each other. This calls for a way to integrate multiple modeling tools in the effort to create a single, large model capable of encapsulating data from multiple, different models. Thus, in this paper, different methods to perform an integration with Systems Modeling Language (SysML) and a simulation tool were identified, described and evaluated. Then, a new method was developed and discussed. Finally, the new method was demonstrated by developing a SysML executable model of a simple two-room house. Using the Functional Mock-up Interface (FMI) standard, the SysML model is integrated with a Modelica model, and a simulation is run in Simulink. Finally, a tradeoff analysis was performed for the purpose of design space exploration.