Cadalyst AEC Tech News #116 (March 18, 2004)18 Mar, 2004 By: Michael Dakan
It’s long been an axiom in the building design world that the quickest and least expensive way to prepare drawings is not to have to draw anything at all, but rather to reuse existing work. The use of 3D CAD on a project eliminates the need to redraw building design drawings as the project moves from one phase to the next. Drawings created in the earliest design phases can be modified and additional information added to serve an entirely different purpose. But using 3D CAD for plans, elevations, and building sections isn’t the only way, or even necessarily the most efficient and timesaving technique, for the use of technology in design practice.
AEC design offices commonly reuse details and other information originally developed for past projects in their current projects. Some details may be reused for years. The use of CAD software in building design offices has strengthened this practice significantly. It’s now very convenient and economical to store and retrieve construction details and other design information in a computer database that you can search by various criteria to find applicable information.
In the past, the retrieval system for old project information usually relied on senior management people who had been with the firm for a while and could remember past projects and the kinds of details used on them. Younger members researching certain kinds of details would ask a senior person, who would tell them to dig out the construction drawings from a certain project from the archive storeroom. Technology has changed all that for many firms that embrace the new approaches that CAD technology allows.
Several years ago, I worked with a large architecture/engineering firm to set up and implement a drawing database system. This drawing database has become a knowledgebase that encompasses the firm’s many years of experience and is used in the firm’s offices throughout the world. This knowledgebase contains not only many construction details that cover all manner of materials and conditions, but also design modules of a range of standardized design information, including exit stairs and restroom configurations, specifications, and specialized construction for specific project types such as criminal justice system facilities, airports, and high-rise office buildings. This firm has measured some astounding savings on project production costs that it attributes solely to the use of the knowledgebase system for many projects to date.
But as economically efficient as this approach to drawing production is, many architects don’t want to use it in their practice. The argument against this approach is usually something to the effect that there shouldn’t be any such thing as “standard” details. Details should be developed exclusively for each project, and all the elements of a building design should be rethought anew for each project.
Of course, I think that many elements of a typical building are pretty standard and see little reason to reinvent the wheel for such things as nonmonumental steel exit stairs in high-rises and code-compliant public restroom layouts. The misgivings I have about detail reuse are the possibility of using them inappropriately and the potential effect on the education and growth of young architects.
No matter how much you stress that the details in the database should not be considered final drawings suitable for use on any project, and that they must be reviewed and modified for every project’s specific conditions, the temptation is strong to use them “as-is” given time and budget pressures on a project team. It’s easy to release a detail without adequate review, especially when everyone knows that they were included in the database to represent the best of the firm’s past experience and knowledge. Besides, they look good and finished just by virtue of being done with CAD.
In the past, an important element of a young architect’s education and training came from drawing details of how buildings go together. To be able to draw the details, the young architect had to think and talk with knowledgeable senior architects about such things as how flashings and waterproofing works, for instance. There’s not much knowledge transferred or mentoring involved with learning how to use software to retrieve a detail and insert it on a sheet. So alternative methods of education and training need to be developed when young architects know a lot about operating a computer and using software and not much about how buildings should go together to keep out the rain.
The application of technology to the practice of architecture has been shown to be very cost-effective and can contribute significantly to a firm’s bottom line. But you also need to consider its potential downside and whether you need to implement mitigating measures in the long-term interest of your firm’s health, and the professions as a whole.
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!