The possibilities of computer simulation also extend to issues inadequately covered by normative analysis and in particular to dynamic aspects of design such as human movement and circulation. The paper reports on a framework for addressing two related problems, (a) the simulation of fire escape from buildings and (b) the simulation of human movement on stairs. In both cases we propose that current evaluation techniques and the underlying design norms are too abstract to offer a measure of design success, as testified by the number of fatal accidents in fires and on stairs. In addition, fire escape and stair climbing are characterized by great variability with respect to both the form of the possible designs and the profiles of potential users. This suggests that testing prototypical forms by typical users and publishing the results as new, improved norms is not a realistic proposition for ensuring a global solution. Instead, we should test every design individually, within its own context. The development of an affordable, readily available system for the analysis and evaluation of aspects such as fire escape and stair safety can be based on the combination of the technologies of virtual reality and motion capture. Testing of a design by a number of test people in an immersion space provides not only intuitive evaluations by actual users but also quantitative data on the cognitive and proprioceptive behaviour of the test people. These data can be compiled into profiles of virtual humans for further testing of the same or related designs.

Environmental psychologists specializing in architectural psychology offer "user needs' assessments" and "post occupancy evaluations" to facilitate communication between users and experts. To compare the efficiency of building descriptions, building walkthroughs, regular plans, simulation, and direct, long-time exposition, evaluation has to be evaluated.

Computer visualizations and virtual realities grow more important, but studies on the effects of simulation techniques upon experts and users are rare. As a contribution to the field of architectural simulation, an expert - user comparison of CAD versus endoscopy/model simulations of a Vienna city project was realized in 1995. The Department for Spatial Simulation at the Vienna University of Technology provided diaslides of the planned city development at Aspern showing a) CAD and b) endoscopy photos of small-scale polystyrol models. In an experimental design, they were presented uncommented as images of "PROJECT A" versus "PROJECT B" to student groups of architects and non-architects at Vienna and Salzburg (n= 95) and assessed by semantic differentials. Two contradictory hypotheses were tested: 1. The "selective framing hypothesis" (SFH) as the subjective theory of planners, postulating different judgement effects (measured by item means of the semantic differential) through selective attention of the planners versus material- and context-bound perception of the untrained users. 2. The "general framing hypothesis" (GFH) postulates typical framing and distraction effects of all simulation techniques affecting experts as well as non-experts.

The experiment showed that -counter-intuitive to expert opinions- framing and distraction were prominent both for experts and lay people (= GFH). A position effect (assessment interaction of CAD and endoscopy) was present with experts and non-experts, too. With empirical evidence for "the medium is the message", a more cautious attitude has to be adopted towards simulation products as powerful framing (i.e. perception- and opinion-shaping) devices.

The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA.

The BDA is implemented as a Windows-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA supplies “smart” default values from a Prototypical Values Database (PVD) for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE and the PVD, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia Case Studies Database (CSD). The next version of the BDA will be linked to additional tools, such as a photo-accurate rendering program and a cost analysis program. Future versions will address the whole building life-cycle and will be linked to construction, commissioning and building monitoring tools.