Ph.D Thesis

Ph.D StudentYezioro Abraham
SubjectForm and Performance in Intelligent CAAD Systems for
Early Stages in Solar Building Design
DepartmentDepartment of Architecture and Town Planning
Supervisor PROFESSOR EMERITUS Edna Shaviv


Great care should be taken at the initial design stages to determine the principles and solution schemes for climate and energy-conscious buildings. The present study deals with supporting the designer's s efforts at the early stages to lay down the appropriate principles for a conceptual and geometric design of energy-preserving buildings, which are also thermally comfortable and adapted to local climatic conditions.

For years important data concerning climate-conscious construction has been compiled, but the information has not been utilized by designers, due to its inaccessibility. It is significant though that solutions based on this knowledge could be found and assessed at the preliminary design steps. A correct climate-conscious design conceived at the initial stages may guarantee that during later phases of the projects' development no problems calling for essential and drastic changes in the basic design will crop up.

The present study proposes a computer-aided passive solar design system (PASYS) which enables the handling of entire designing process, and its general, conceptual aspects, as well as the preliminary designing steps and their particular, practical aspects. The system is based both on a knowledge base which stores the existing information concerning solar-climatic construction in the form of rules of thumb, and on precise procedural models which enable finding solutions suited to the local climatic conditions.

The proposed system is an intelligent CAAD system which equips the designer who is aware of the constraints of climate and energy, with a tool to achieve a better design. PASYS was developed as a universal system to deal with the various activities involved in the initial - pre-conceptual and conceptual - design stages. The system supports the following design activities of each stage of this kind: analysis, synthesis, documentation, assessment and decision making. It is capable of analyzing given conditions, thus helping the designer understand which are the significant preliminary design stages that have a bearing on thermal comfort conditions in a given climate. The system is also capable of proposing solutions corresponding with the particular design phase, and assess their adequacy. These solutions take into account the constraints determined both by the designer and by the system itself, owing to the knowledge base it contains. The system can also document the various solutions that have been found and selected, so that may be further developed at later stages. This documentation is carried out by a graphic interface, developed as part of the system, as well as by an interface devised for existing CAD software.

This study highlights the interaction between form and performance. The system is able to assess the performance of a proposed design by considering a given geometry (form), or vice versa, it is able to recommend a solution that can deliver desired and required performances.

This system enables the designer, even at the preliminary design stages, to determine which properties relating to local climatic conditions he will introduce into the building. This important, seemingly natural act is usually performed during more advanced stages, when it might generate significant changes in the design, at a juncture when changes are hard to make. A PASYS-aided design environment ensures that from the beginning of the designing process the project will be designed correctly and efficiently as far as energy is concerned.