Generative modeling and numerical optimization for energy efficient buildings

A procedural model is a script, which generates a geometric object. The script´s input parameters offer a simple way to specify and modify the scripting output. Due to its algorithmic character, a procedural model is perfectly suited to describe geometric shapes with well-organized structures and repetitive forms. In this paper, we interpret a generative script as a function, which is nested into an objective function. Thus, the script´s parameters can be optimized according to an objective. We demonstrate this approach using architectural examples: each generative script creates a building with several free parameters. The objective function is an energy-efficiency-simulation that approximates a building´s annual energy consumption. Consequently, the nested objective function reads a set of building parameters and returns the energy needs for the corresponding building. This nested function is passed to a minimization and optimization process. Outcome is the best building (within the family of buildings described by its script) concerning energy-efficiency. Our contribution is a new way of modeling. The generative approach separates design and engineering: the complete design is encoded in a script and the script ensures that all parameter combinations (within a fixed range) generate a valid design. Then the design can be optimized numerically.