Building Information Modeling: Revit v. CAD

The key difference between Revit and any other Building Information Software program I have used in the past is that Revit specializes in change management. This means that when a change is made in one document or view of your project, that change is made through out the set of documents or views. This is made possible through Revit’s parametric change engine that allows the program to understand intelligent relationships between objects. For example, when you draw a wall in CAD it is represented as two parallel lines. Revit understands that those lines represent a wall, and that that wall is connected to that square that represents a roof, and so on. Because Revit works with parametric objects, with distinguishing and separate features, this makes customization very easy. As an example of the difference lets look at how to change the height of an object. In CAD you use the scale tool, which subsequently changes the size of the entire object. In Revit, you simply change the height parameter of the object.

            Another major difference between Revit and CAD is the ability to view your project in multiple dimensions. Unlike CAD, which only allows you to describe your project in two dimensions, Revit actually assembles a three-dimensional model of your project. Thus allowing you to have a more complete understanding of what it is you are constructing.

Building Information Modeling: Parametric Modeling

Parametric modeling:

 Is the act of creating a space or an object using a set of defining parameters or relationships. It is through these established parameters that the object is both given its defining characteristics, and its editable/customizable properties. These relationships can appear within a single object or in between multiple objects.  

Cultural Self Portrait

We are in the beginning stages of designing the new Center for New North Carolinians. So we were asked to look at our own heritage, and what it means to us to be an American. This poster also includes a hand drawn self portrait, a picture from our childhood, and a concise listing of our ancestors.

"Computing in Architectural Design" summary

“Computing in Architectural Design” by Yehuda Kalay is essentially a history of how computer technology came to exist in the design profession at the level at which it does today. This article highlights some of the key struggles and landmark accomplishments encountered during the development of these technologies.

Kalay begins with a brief history of computation in general. He talks about the use of geometry in architecture to calculate areas, sizes, and volumes as they related to the built environment. Proportion was also of critical importance when Kalay spoke of the Renaissance, the Vitruvian ideal, and the quest for architects to create designs using the most “perfect” geometrically proportional relationships, between building components i.e. the golden section. The development of perspective as a calculated method of drawing was also an important step for architects as a means of communicating their designs. In addition to space planning and effective design communication, Thomas Young developed calculations and computations as tools for predicting structural performance and building safety in 1807.

Kalay also writes that the first computers used in building design were used for engineering analysis, and to study the transfer of forces within a structure. The first software program used to do this was developed at the University of Michigan. The program they developed, abbreviated CAEADS, and was a system that conducted habitability, engineering, and building specification verification analysis. Another example of analysis software, called Building Design Advisor (BDA), was developed at the Lawrence Berkeley National Laboratory for performing energy related building performance computations, which took into account climate data, building material characteristics, etc. One might say this was similar to a primitive version of Ecotect.

It wasn’t until 1963 when computers were used to actually aid in the design process. This began with Ivan Sutherland’s Sketchpad system, which took the designers sketch and made it into a perfect architectural drawing. The idea of computer aided drafting, though a good one, didn’t step out of the laboratory and become practical for professional use until the creation of Macintosh in 1984. Along with the development of the personal computer, software was created to make drafting and modeling on these machines possible. With the appearance of the PC, multiple view ports were also added to these types of software.

As it was mentioned earlier in this essay, perspective-drawing techniques were developed as a calculated means of visual communication. Companies such as Revit, and Graphisoft, among others mentioned in Kalay’s article, have developed computative rendering software for the design profession. These programs, like perspective drawing, added another element of realism, and dimension to developing projects. Reading Kalay’s article helps one to appreciate and respect the power technology gives us as designers to understand our designs, and communicate our ideas.