A study of illegal housing of Lisbon built in 1974 to 1984 : from description to computation

Abstract

A morphological description of illegal housing built by homeowners in the Metropolitan Area of Lisbon between 1974 and 1984 is presented. This description is based on a parametric set grammar that attempts to formulate both topological and geometric aspects of the house. Therefore, the grammar is made of shapes, symbols, and their relations in space. The architectural description herein considers aspects of structure, function and use. The main characteristic of this illegal housing is that design and building are here the inhabitant's responsibility. These houses are usually seen by society as a chaotic and ugly constituent of the built environment. Yet for the users these are dream houses, shaped with symbolic references that helped assure each homeowner a good assimilation into the big city. Three basic goals led to this study: first, to search for a better understanding of these dream houses despite their many contradictions, second, to find a formal representation despite the chaotic appearance and genesis of these illegal houses, and third, to contribute to the formalizing of a computer implementation that could help to prevent further echoes of this scenario.

(cont.) As analyses and synthesis may not have the same type of description, relating the substance of representation, both inside or outside computation, and the processes that should work with that representation became an important issue for the work herein. The result creates a speculative framework which, it is hoped, will help to define a computer representation of an architectural chain that can deal with the complexity of scaling house representation from abstract to concrete. Therefore, some considerations are made regarding shape grammars and their ancillary grammars, as well as the heuristic processes that may operate with those grammars.