Optimizing the “characteristic structure” Combining shape grammars and genetic algorithms to generate urban patterns

Abstract

The present paper is part of an undergoing research that aims at developing software that can generate urban plans, based on contemporary urban design concepts, in an optimized way. As a design method, the project proposes the use of the trilogy formulation/ generation/evaluation, which starts with an outline of the design requirements, proceeds with the definition of generative procedures that can result in these requirements, and follows with the evaluation of the generated designs. The paper describes the development of a computer program that implements some of Marshall’s evaluation methods, and further elaborates them to define generative criteria and to optimize the resulting designs with GA techniques. The program aims at generating what Marshall calls a “characteristic structure”, a type of urban fabric that is usually found in vernacular urban fabrics.