I have worked with CAD for buildings for years both as a student and, after my master of architecture degree, as a designer. My interest has been to integrate computers with my work process. This interest eventually led to my PhD study in the area of building engineering with specialization in computer-aided building design (CABD). I focused on the early building design process with particular attention on the workspace, on how designers use diagrams to communicate and record design parameters and building components. I published a description of this process [1] as well as a set of specifications [2] that can be used in the creation of software that can provide appropriate support.
The Buildes project is an effort that borrows largely from this work with the goal of realizing and maintaining a production ready software for computer-aided building design. There are four main areas of interest.
The fundamental and universal interface for computers is text. Working with plain text increases the versatility and power while reducing the required resources. Design sessions in buildes are completed using scripts. These are plain text files that contain keywords for describing building parameters and components. An effort is made to structure these keywords so that they are intuitive to use when creating building components for example the designer will use the keyword site to create a building site object and the keyword space to create a building space object. During creation, the designer must provide a unique name for a component for easy reference in the design. For example the designer can create a site component that is called “Foo’s Residence at Bar” or a space object called “Living room”.
Building knowledge captured in current CAD systems focus on graphic characteristics of the boundary components such as walls and floors. This focus obfuscates other crucial parts of the building to the point where critical information or data about the building is often wrong, missed, or at best require to be ‘re-figured’. Our research shows that the fundamental component in the building is the building space. Therefore we focus on capturing data produced while creating, manipulating and configuring the building space.
Hierarchical decomposition of building components
The building space defines an enclosure that is bounded by solid or transparent sides. The space owns its sides and so knows how to access their location and condition. Sides from different spaces can share position and sometimes specification. When there is a shared side, the shared portion must be detailed in a way that accounts for the needs of the two spaces. Spaces have a locational or positional hierarchical relationship in which one can be found within another. This idea of focusing on the building space object is the founding concept with which Buildes captures and stores information about the building.
The complexity of buildings is at the point where many factors have to be considered to cost-effectively provide an appropriate solution. Software tools are sophisticated and should be designed to provide appropriate real-time feedback to the designer regarding consequences to design decisions. By utilizing the hierarchical relationship inherent in the building space, Buildes is able to determine, for example the proximity of components. Also, by utilizing the concept of shared boundaries, Buildes is able to facilitate communication and interaction between space objects. With features like these, Buildes is able to ‘reason’ and/or ‘react’ to the designer’s decisions based on available building knowledge and be able to provide appropriate feedback. For example building setbacks are captured as space objects with transparent sides. During the design process, Buildes monitors setback objects and warns the designer when any of the boundaries, depending on other constraints, is breached.
The building design process requires input from many professionals and in addition, there are many options in available software tools for a variety of tasks in the building design process. It is important for data entered into software tools to be based on available and widely used standards. It is equally important for data in software to be easily accessible to the users so that the information can be moved around transparently between users and their preferred software tools. Buildes is free software as well as an open source software. As such, it is easy to see how it does its work. Buildes provides many options for exporting the information it creates, all of which are open formats. Buildes is written in Python and its objects are python classes. Our goal, by the time we reach a production-ready version of Buildes, is to export a widely accepted BIM file format. More information about this will be provided as the program matures.
Footnotes
| [1] | Kene Meniru “Sketching and Designing Buildings with Computers” LAP Lambert Academic Publishing (2010-06-14) p244 |
| [2] | K Meniru, H Rivard, C Bedard. “Specifications for computer-aided conceptual building design” Design Studies Vol 24 No 1 (2003) 51–71 |
