This research recognizes the need for building simulation/performance tools that can easily be integrated into the building design process. The study examines available simulation tools and attempts to determine why these tools are not used by building designers/architects. Findings confirm that the complexity of simulation tools created by scientists, who are more technically oriented, discourages use by architects who are more visually oriented people. The evaluation and analysis of available simulation tools suggests a thorough research methodology for creating a new front-end interface that solves current usage problems. The research is limited to the interface design of the new front-end which is named Integrated Building Design Information Interface (IBDII). The new front end provides an interface that allows designers to make more informed decisions during the design process while providing a front-end that supports AutoCAD and permits a user interface where the mode of input is graphical and not numerical. Criteria for the new front-end interface enable the development of a series of mock-up interface designs that are responsive to the needs of architects. A working graphical user interface of the building information prototype is created and is then put through an empirical user testing. The usability testing establishs the usefulness, effectiveness, likeability and learnability of the developed interface design. The testing includes six factors which act as indicators of usability and provide suggestions for future developments. The testing evaluation ascertains that the interface is easy to learn and use. Findings also show that the best feature of integrated building design information front-end is its interface design and there is room for improvement in the way input is selected.