ABSTRACT
This chapter locates some of the obstacles to defining the optimal while also suggesting ways around them. The typical opening for literature dealing with performance issues in architecture would highlight the importance of statistical data in order to save energy in the building sector while emphasizing that there is room for improvement. In the theoretical context of avoiding the architect as master creator, making design decisions based on styles or ideological allegiances and in general imposing a subjective will on the material, performance-based design can be used to generate new and even unpredictable forms. A relatively new user might hear about the whole-building energy model (WBEM) and be excited about the ease with which a certain software package can execute such analysis. The omission within most WBEM frameworks is the dynamic and differential effect of the sun and solar gains, flattening lighting power density (LPD) into a single number.
