Keywords Abstract
Harfmann, A.C., B. Majkowski, and S.S. Chen. "A Component-Based Approach to Building Product Representation and Design Development." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 437-452. CAAD Futures. Amsterdam: North-Holland, 1993. This paper presents the development of the component-based approach for building product representation and suggests its appropriateness for incorporation at any stage in the design process. The efforts focus on resolving the conflicts that arise when the common denominator of component level representation in utilized throughout the process of designing a building.
Ozel, Filiz. "A Computerized Fire Safety Evaluation System for Business Occupancies." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 241-251. CAAD Futures. Amsterdam: North-Holland, 1993. The development of computer-based code compliance checking programs has been the focus of many studies. While some of these investigated the procedural aspects of building codes, others focused more on their rule base. On the other hand, due to the complexity of the codes, the process of identifying which sections apply to a given problem, and in which order to access them requires a meta-knowledge structuring system. National Fire Protection Association (NFPA) 101M, Alternative Approaches to Life Safety (1992) provides a framework through which code sections can be systematically accessed by means of a set of checklists. The study presented here primarily focuses on the development of a computer based fire safety code checking system called ARCHCode/Business for business occupancies following the guidelines and the methodology described in Chapter 7 of NFPA 101M.
Liu, Yu-Tung. "A Connectionist Approach to Shape Recognition and Transformation." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 19-36. CAAD Futures. Amsterdam: North-Holland, 1993. In human design processes, many drawings of shapes remain incomplete or are executed inaccurately. Cognitively, a designer is able to discern these anomalous shapes, whereas current CAAD systems fail to recognize them properly so that CAAD systems are unable to match left-hand-side conditions of shape rules. More unfortunately, as a result, current CAAD systems fail to retrieve right-hand-side actions. In this paper, multi-layered neural networks are constructed to solve the recognition and transformation of ill-processed shapes in the light of recent advances of connectionism in cognitive psychology and artificial intelligence.
Bedell, John, and Niklaus Kohler. "A Hierarchical Model for Building Applications." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 423-435. CAAD Futures. Amsterdam: North-Holland, 1993. Advanced computer-aided architectural applications must model buildings as multi-level compositions supporting distinct points of view. Hierarchies of encapsulated, autonomous elements can be derived from ISO-STEP's General AEC Reference Model and configured for various applications. For analysis of life-cycle costs, we define a Pyramid of evaluable production steps leading to the final building, for optimization of renovation task schedules, a topological model of access paths and traffic flow. These separate viewpoints can be embedded in a single unifying structure permitting the communication and propagation of changes among its specialized aspects.
Smeltzer, Geert, and Jan Dijkstra. "A Time Dimension for Computer-Aided Architectural Design Systems." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 391-403. CAAD Futures. Amsterdam: North-Holland, 1993. This paper presents the importance of a time dimension for CAAD systems and describes the idea and research intentions to implement this dimension as a new aspect of design information. A time dimension is proposed as a tool for the organization of design information and for the reproduction of design processes. The aim of the research is to propose a facility to record all design states generated during an architectural design process, in a temporally coordinated manner in one information system. Such an information system should make it possible to have the computer register and reproduce the design process in a procedural manner and compare different design states. This will lead to a better analysis and evaluation of design states and to a possible analysis and evaluation of design processes.
Hovestadt, Ludger. "A4 Digital Building: Extensive Computer Support for Building Design, Construction, and Management." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 405-421. CAAD Futures. Amsterdam: North-Holland, 1993. The integrated design, construction, and management of buildings are described as being of unlimited complexity. The data structures required to support these tasks cannot be predefined and have- to be worked out during the design process. An instrument that integrates weakly and strongly structured data is necessary. A4 proposes - as a minimal structuring mechanism - the position of information in a dataspace. It offers diverse additional and optional structuring mechanisms. Examples from different domains show the particular strengths of the A4 integration model.
Meyer, Steven, and Steven Fenves. "Adjacency Structures as Mappings Between Function and Structure in Discrete Static Systems." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 175-193. CAAD Futures. Amsterdam: North-Holland, 1993. We present a graph-based method for mapping between functional requirements and physical structure in discrete static systems. Through forward or backward chaining, this method may be used in a generative mode to suggest instances Of system structure satisfying the desired functionality, or in a parsing mode to uncover the behaviour and function of a given system. The graph may be composed from a geometric model, but the method is independent of any specific geometric modelling representation. We focus on the domain of structural systems in buildings to describe this method.
Oltman, P.K., I.L. Bejar, and S.H. Kim. "An Approach to Automated Scoring of Architectural Designs." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 215-224. CAAD Futures. Amsterdam: North-Holland, 1993. An automated approach to scoring architectural designs of building sites was devised. Design drawings were represented in the computer as a database consisting of a series of objects and their locations and relationships to other objects. Designs were automatically scored by: (a) determining whether or not certain basic requirements were met (such as parking, handicapped access, and building within site boundaries) and (b) determining the extent to which the drawings met criteria of efficient site design. The drawings had been scored earlier by a panel of expert registered architects. The automated technique was able to reproduce the human jurors'ratings for many drawings. In particular, drawings that the automated technique failed were quite likely to have been failed by human jurors as well.
Gudna, François, and Khaldoun Zreik. "Analogy, Exploration and Generalization: Three Activities for Knowledge-Based Architectural Design Systems." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 255-272. CAAD Futures. Amsterdam: North-Holland, 1993. We propose in this article a system architecture based on reasoning through analogy with past cases or situations. Starting with a project and a sketch provided by the user, the system locates analogous situations in the past and uses these to improve a problem's description. A sufficiently improved description will in turn activate a constraint-satisfaction mechanism. Previous situations are stored in a memory bank of objects that match the description of past problems to the generic descriptions of past solutions. Three mechanisms can be distinguished within the system: an analogy mechanism collects hypotheses about the variables and constraints to be satisfied in past situations, an exploratory mechanism searches through the solution space, a generalizing mechanism looks at experiences and memorizes only what is needed to collect hypotheses.
Coyne, R.F., U. Flemming, P. Piela, and Robert F. Woodbury. "Behavior Modeling in Design System Development." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 335-354. CAAD Futures. Amsterdam: North-Holland, 1993. We describe the development approach for a software environment to support the early phases in building design called SEED. The combination of capabilities offered by SEED to designers is novel and includes the integrated handling of solution prototypes. We give the reasons for using an object-oriented software engineering approach in the development of the system, which starts with a comprehensive behavioural model of the system from the user's perspective based on actors and use cases. We illustrate results from the first development phase and sketch the next phases. At the time of the CAAD Futures'93 conference, we will be able to report our experience in developing a first system prototype and to demonstrate the prototype.
Dave, Bharat. "CDT: a Computer-Assisted Diagramming Tool." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 91-109. CAAD Futures. Amsterdam: North-Holland, 1993. This paper describes the development of a computer- based diagramming tool (CDT) that supports incremental structuring of problem information using diagrammatic representations. Diagrams as graphic representations of symbolic propositions allow tentative reasoning and inferencing. The development of CDT has been carried out based on two observations. First, many diagrams are used to represent objects and relations between them. Second, diagrams comprise graphic Symbols arranged on a plane using topological and geometric relations to denote problem relevant information. CDT responds to these needs by incorporating a number of computational ideas: graphic interface, direct manipulation, constraint representation by demonstration, and specification and satisfaction of diagram composition rules.
Bhat, R.R., J. Gauchel, and S. Van Wyk. "Communication in Cooperative Building Design." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 481-493. CAAD Futures. Amsterdam: North-Holland, 1993. This paper addresses communication issues, which are crucial in any implementation of distributed design environments. Communication needs are specified and implemented in a prototype based on a modular knowledge-based approach for simulation of a distributed multi-user system. The results of these simulations are reported, which show communication to be scalable as the numbers of applications and the size of the design increases. Finally, the implications of the results on real distributed systems are discussed.
Wright, Robert, and Rodney Hoinkes. "Computational Issues in Urban Design: Developing a Strategy for Solar Impact Assessment." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 543-555. CAAD Futures. Amsterdam: North-Holland, 1993. A comprehensive method for identifying the impacts on solar access of large scale architectural projects still continues to be an important and controversial area in city planning and urban design. Previous research studies such as the Sun Wind and Pedestrian Comfort, a study of Toronto's Central Area, demonstrated approaches possible when dealing with solar issues related to urban design. Existing  techniques for solar inventory, analysis and evaluation, while effective, are often dependent on single event analysis (shadow casting) or manual procedures that are time consuming and exceedingly complex especially when needed for day-to-day use by planners or architects involved in complex urban projects. The Centre for Landscape Research has undertaken as part of its research to develop a computational approach that would help city urban designers evaluate and represent the issues of solar access in an urban setting. This paper will outline a series of computational methods developed to utilize an existing municipal digital data base and to describe complex issues of solar access in terms of urban form and context. A technique will be described that quantitatively assesses the total solar potential of a site as compared to changes in solar access due to different urban design proposals. Two-, three- and four-dimensional representation techniques are developed to facilitate understanding of the analysis to users such as city officials, the public, developers, etc.
Lindsey, Bruce, and Paul Rosenblatt. "Cutting up Time: Craft and Technology in the Niches Project." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 523-541. CAAD Futures. Amsterdam: North-Holland, 1993. In this paper, which will cite as illustrations some of the documents that have resulted in the completion of the Carnegie Mellon University College of Fine Arts Niches, we will discuss the interdependent relationship between craft and technology in architectural computer modelling practice. We will suggest that practical uses of the computer demand the counterbalancing intimacy of craft in the design studio. Our goal in the Niches Project was to couple direct tactile experience, historical knowledge, and the precise operations afforded by computers.
Carlson, Christopher. "Describing Spaces of Rectangular Dissections via Grammatical Programming." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 143-158. CAAD Futures. Amsterdam: North-Holland, 1993. For the description of design spaces, grammatical programs offer several advantages over conventional grammars: (1) they integrate rewrite rules with more general non-deterministic functions, (2) they permit a range of programming styles from purely declarative to purely procedural, (3) they can describe spaces Of constrained, parametric designs, and (4) they permit design space descriptions to be developed modularly. We demonstrate these features of grammatical programming by way of a simple example that generates spaces of rectangular dissections.
Gero, John S., and Min Yani. "Discovering Emergent Shapes Using a Data-Driven Symbolic Model." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 17-Mar. CAAD Futures. Amsterdam: North-Holland, 1993. This paper presents a model for discovering emergent shapes based on the concept of shape hiding and data-driven search. It is founded on representing polyline bounded shapes using infinite maximal lines, an extension of the concept of maximal lines. A process model of shape emergence is presented and a number of examples given which demonstrate the utility of both the representation and the model.
Stiny, George. "Emergence and Continuity in Shape Grammars." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 37-54. CAAD Futures. Amsterdam: North-Holland, 1993. Standard topological devices can be adapted for shapes, and then used to establish the continuity of computations in a shape grammar. This explains how shapes are structured in relation to one another as rules are applied in computations, even when emergence plays a crucial role.
Dagit, Charles. "Establishing Virtual Design Environments in Architectural Practice." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 513-522. CAAD Futures. Amsterdam: North-Holland, 1993. This paper attempts to specify the ideal computerized architectural design tool and outlines steps that are being taken to make this ideal a reality. Section 2 offers a user-centered assessment of the way technology is currently implemented in the design professions. Section 3 describes the state-of-the-art in high-end CAAD applications, including computer rendering, walk-through displays, and expert diagnostic sysWins. Section 4 details work in progress at Worldesign, Inc., a virtual worlds systems integration firm, which is developing Virtual Design Environment (VDE) systems.
Saggio, Antonino. "Hypertext, Solid Modeling, and Hierarchical Structures in Formal Architectural Analysis." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 289-309. CAAD Futures. Amsterdam: North-Holland, 1993. The paper presents computer reconstructions of unbuilt projects relevant to the history of Italian rationalism together with the potential and limits of three CAAD environments. While an evaluation is provided for each one, a more detailed attention is devoted to hierarchical structures because of their capability to capture knowledge, to support further investigations, and to provide new insights into architecture. A model built in this environment allows simultaneously (1) the analysis and reconstruction even of a complex project at the size of a personal computer, (2) the simulation and test of different material, crucial in the case of restoration or in the case of incomplete and uncertain original project data, (3) the critical analysis (but also the co-presence of the different project alternatives of design phases) through the reading at the various level of the hierarchy, and (4) free investigation on the structure of data that can support new critical hypothesis and insights that were not anticipated at the moment of project creation.
Papazian, Pegor. "Incommensurability of Criteria and Focus in Design Generation." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 111-125. CAAD Futures. Amsterdam: North-Holland, 1993. An approach to developing design systems is presented, informed by the recognition that design criteria are incommensurable. The degree to which an artifact satisfies one criterion cannot be compared to the degree to which it satisfies another. Given this principle, it is not valid to combine different “scores” given to independent features in an evolving design into a global evaluation function. The design framework proposed here represents an alternative to the traditional approaches for combining independent criteria and organizational principles. It is based on the opportunistic nature of designing, the multiplicity of semantics active in a design session, and the dynamics of focus and distraction. By way of illustrating both this characterization of designing and the abstract computational framework on which it is based, a simple system for arranging blocks according to a set of formal massing principles is presented. The massing generator has some important properties that other systems lack, such as dynamism, robustness and the ability to deal with partial designs. Through a comparison with some artificial intelligence methods such as production systems and search, the proposed framework is used as a guideline for developing design systems. This paper focuses on designing as an activity, rather than engaging in an analysis of finished designs with the hope of capturing their syntactic properties. Thus the stress is placed on the generator's behaviour, by giving examples of how it converges on a series of design alternatives in a dynamic fashion, avoiding oscillations and blocks.
Van Nederveen, S., W. Bakkeren, and B. Luiten. "Information Models for Integrated Design." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 375-390. CAAD Futures. Amsterdam: North-Holland, 1993. A major problem in the development of integrated systems for building design is the complexity of building design information. This paper discusses a number of abstraction mechanisms for information modelling, which help to reduce the complexity of building design information, without losing semantics. A distinction is made in universal mechanisms and mechanisms for building design information. The usage of the mechanisms is illustrated with an example of a building type model.
Müller, Volker. "Introducing CAD to a Big Corporation." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 497-512. CAAD Futures. Amsterdam: North-Holland, 1993. The report presents the ongoing activity of introducing CAD to the entire range of facilities planning and management of the Frankfurt Airport Corporation. It addresses issues of organizing the shift from conventional to computer supported planning and facilities management,- the problems of training professionals with various background in the use of new tools, aspects of data validity, regulation of data exchange, and customization of software to the needs of special tasks within the corporation. The report is based on about four years of project runtime. The preparation of the project started in fall 1988. The project proper started in June 1989. It is entering its last year. Up to now about 120 persons have been trained to use CAD.
Grant, Mike. "Issue - Interactive Software Systems for the Urban Environment." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 557-564. CAAD Futures. Amsterdam: North-Holland, 1993. The research reported here sought to examine the prospect for linking data sets which are currently isolated within specific departments or held externally by utility companies or businesses each of whom are likely to benefit from pooling resources. These data sets are potentially capable of being merged into one comprehensive system with the prospect that the sum of the parts would be worth considerably more than their individual worth suggests.
Rutherford, James. "Knodes: Knowledge-Based Design Decision Support." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 357-374. CAAD Futures. Amsterdam: North-Holland, 1993. This paper describes the work in progress to develop a knowledge-based design support (KNODES) environment. The KNODES environment is intended to improve a designer's decision making potential, and to assist designers in a broad range of disciplines by making design knowledge and information more accessible. The framework exists as a multi-layered knowledge-based system reflecting both generic and domain specific aspects of the design activity and is designed to: enable the rapid dissemination of new design information, thus responding to shifts in design standards, take advantage of existing empirical design tools in unstructured areas of the design process, accommodate changes in user expectations and technological innovations at both the system and domain levels thus ensuring long term continuity and support,- offer multiple view points of the same design data by means of interchangeable interpreters. A prototype building design framework configured using the KNODES development tools is used to illustrate some of the salient features of the framework. Finally the paper will conclude with some insights into how such a design framework may be used as a knowledge acquisition tool in order to derive and formalise models of the design process.
Woodbury, Robert F., and Eric Griffith. "Layouts, Solids, Grammar Interpreters and Fire Stations." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 75-90. CAAD Futures. Amsterdam: North-Holland, 1993. This paper is presented in three main parts. First, it reports the results of an effort to combine two representations (layouts and solid models) within a single generative framework. Second, it describes fire stations as a building type and reports a phased grammar that embodies information about the type and generates fire station designs likely to be members of the type. Third, it describes a useful way of controlling grammatical generation via interactive decisions on rule application, hierarchical decomposition of designs, and ordering of the conflict set of rule instantiations.
Bhavnani, S.K., J. Garrett, and D.S. Shaw. "Leading Indicators of CAD Experience." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 313-334. CAAD Futures. Amsterdam: North-Holland, 1993. Current interfaces and help facilities of CAD systems are not designed to respond to a user's performance. To develop such adaptive environments, a better understanding of the indicators of CAD experience is required. This paper discusses the results of studying behaviour patterns of different types and levels of CAD users for a specific drawing task. The results show that the type and experience of the CAD user has a clear correlation to the pattern of commands used, the time taken, and the quality of drawing produced. By using the experimental data to train a neural network, the paper demonstrates a connectionist approach for experience assessment. This information, it is proposed, can provide input to an adaptive interface which generates unobtrusive interception to improve the performance of a CAD user. Future experiments to explore the issues of generality and interception are presented.
Vanier, Dana. "Minicode Generator: a Methodology to Extract Generic Building Codes." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 225-239. CAAD Futures. Amsterdam: North-Holland, 1993. This paper describes work in progress. It summarizes the methodology for analyzing building codes and isolating generic building characteristics. These characteristics can be used by building code experts to markup code documents and subsequently by building code users to extract code provisions that apply to their projects. Although this methodology has been developed for the National Building Code of Canada, it can be applied to any model code and implemented on most computer platforms using off-the-shelf software. The paper outlines the scope of the research, the historical development, the problems encountered, and paradigms for markup and extraction of code provisions.
Mahdavi, Ardeshir. "Open Simulation Environments: a “Preference-Based” Approach." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 195-214. CAAD Futures. Amsterdam: North-Holland, 1993. This paper introduces in conceptual, algorithmic and implementation terms, the notion of an “open” simulation environment as a “multidirectional” approach to computer-aided performance modelling. A “preference- based” formalization of design intentions/criteria is proposed to cope with the “ambiguity” problem through dynamic control of degrees of freedom of relevant design-related parameters during the interactive design process. A prototypical realization of an open simulation environment called “GESTALT or simultaneous treatment (parametric manipulation) of various design and performance variables is demonstrated. Some preliminary results of computer-assisted generation of performance-responsive designs are presented.
Paoluzzi, A., V. Pascucci, and M. Vicentino. "PLASM Functional Approach to Design: Representation of Geometry." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 127-141. CAAD Futures. Amsterdam: North-Holland, 1993. PLASM (the Programming Language for Solid Modelling) is a solid-modelling-oriented design language strongly inspired by the functional language FL. In a PLASM environment, every geometrical object is generated by evaluating a suitable language expression which produces a polyhedral solid model. The language adopts a dimension-independent approach to geometry representation and algorithms. The generated objects are always geometrically consistent since the validity of geometry is guaranteed at a syntactical level. In fact (a) each well-formed expression is obtained by proper composition of well-formed subexpressions, (b) the evaluation of a well-formed (and polyhedrally typed) expression produces a valid solid model. In this paper, the representation scheme used in the language is given and some language scripts are shown and discussed.
Oxman, Rivka, and Robert Oxman. "Precedents: Memory Structure in Design Case Libraries." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 273-287. CAAD Futures. Amsterdam: North-Holland, 1993. The paper presents an approach to a memory structure of design ideas in a library of design precedents. A model of case memory for design is developed. The model is composed of distinct chunks of knowledge called design stories. A formalism for the design story is proposed which represents the linkage between design issue, concept and form in stories. Stories are structured in memory according to a semantic network. The lexicon of the semantic network acts as a memory index. The memory structure and indexing system are demonstrated to enhance search and to support crosscontextual browsing and exploration in the precedent library. The approach is demonstrated in a pilot design aid system in the task domain of early conceptual design in architecture.
Flemming, Ulrich, and Ardeshir Mahdavi. "Simultaneous Form Generation and Performance Evaluation: a "Two-Way" Inference Approach." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 161-173. CAAD Futures. Amsterdam: North-Holland, 1993. The conventional approach toward performance evaluation transforms given design attributes into performance indicators, and designers can improve these indicators only indirectly through the manipulation of design attributes. This paper outlines a contrasting “two-way” inference approach that allows designers to also manipulate the performance indicators directly and observe the resulting changes in design attributes. The advantages of this approach and its limitations are outlined. Methodological and implementation difficulties that arise from it are introduced, and possible solution strategies are described. A first prototype for a system that implements and demonstrates this approach is outlined. The larger debate about'functionalism'touched by this approach, and its response to it, are briefly reviewed.
Krishnamurti, Ramesh, and Rudi Stouffs. "Spatial Grammars: Motivation, Comparison, and New Results." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 57-74. CAAD Futures. Amsterdam: North-Holland, 1993. The paper starts by giving a motivation for studying grammars in design and is based on considerations of style, discovery, and constructive techniques. This paper goes on to survey a variety of spatial grammar formalisms from an implementation standpoint. For each formalism, the salient computational issues pertaining to rule application are discussed. Two aspects of shape grammars are considered in detail: (a) the conditions for reversibility of shape rules, and (b) the recognition of planar shapes. 
Maher, Mary Lou, John S. Gero, and M. Saad. "Synchronous Support and Emergence in Collaborative CAAD." In CAADFutures '93: Proceedings of the Fifth International Conference on Computer-Aided Architectural Design Futures, 455-470. CAAD Futures. Amsterdam: North-Holland, 1993. Design is rarely an activity that is commenced and completed by an individual The more common design environment is one in which teams of designers work together towards a final solution. In this paper we consider issues involved in the development of computer-based design environments in which teams of design professionals can collaborate, focusing on the need for visual and underlying representations which can support multiple interpretations. We consider the environment as providing a shared workspace which facilitates both communication and progression of design ideas, concepts, and drawings. In the environment presented here, the shared workspace has two foci: the workspace that designers see and interact with, and the workspace that provides an underlying computer-based representation for persistent memory. The emphasis is on providing representations that support emergence that occurs during collaboration.