Comparing Prioritization Strategies in Multi-Objective Design for an Enclosed Atrium

When structural designers attempt to achieve multiple performance goals at once, multi-objective optimization (MOO) tools may be of assistance. Yet in conceptual structural design, the application of MOO may be less structured than methods described in engineering textbooks. This paper analyzes the behaviors of participants in a recent design study to observe the range of prioritization strategies when designers are pursuing multiple performance objectives. The study asked participants to consider structural efficiency, solar radiation, and daylighting goals while designing an enclosed atrium using the elements of an optimization problem: design variables and objectives. The sessions were recorded and analyzed for actions that demonstrated pursuit of one or more performance objectives, alongside interviews that allowed participants to describe their approach in more detail. The study participants were nearly evenly split between sequential and simultaneous optimization strategies for objectives, with most sequences beginning with a focus on structure. Tool selection seemed to be largely based on familiarity, with evolutionary algorithms being the most common. Observations of these behaviors from a live design task can supplement existing knowledge on the use of optimization in design practice.