Energy related design decisions deserve simulation approach

Building energy consumption and indoor climate result from complex dynamic thermal interactions between outdoor environment, building structure, environmental control systems, and occupants. This reality is too complicated to be casted in simple expressions, rules or graphs. After a general overview of building energy design tools, the paper describes how / why computer simulation systems can / should be used for design decision support related to building energy performance. The main conclusion is: design decision support (systems) should employ comprehensive building energy simulation models, the designer should be able to "see" energy flows in a design alternative, and the machine should do the work