Figure 1.1 A CAD-based workflow
In a BIM-based workflow, the team creates a 3D parametric model and uses this model to generate the drawings necessary for documentation. Plans, sections, elevations, schedules, and perspectives are all by-products of creating a building information model, as shown in Figure 1.2. This enhanced representation methodology not only allows for highly coordinated documentation but also provides the basic model geometry necessary for analysis, such as daylighting studies, energy usage simulation, material takeoffs, and so on.
Figure 1.2 A BIM-based workflow
Leveraging BIM Processes
As architects or designers, we have accepted the challenge of changing our methodology to adapt to the nuances of documentation through modeling rather than drafting. We are now confronted with identifying the next step. Some firms look to create even better documents, whereas others are leveraging BIM in building analysis and simulation. As we continue to be successful in visualization and documentation, industry leaders are looking to push BIM to the next level. Many of these possibilities represent new workflows and potential changes in our culture or habits, which require you to ask a critical question: What kind of firm do you want, and how do you plan to use BIM?
As the technology behind BIM continues to grow, so does the potential. A host of things are now possible using a building information model; in fact, that list continues to expand year after year. Figure 1.3 shows some of the potential opportunities.
Figure 1.3 Service opportunities that BIM supports
We encourage you to explore ongoing research being conducted at Penn State University (http://bim.psu.edu), where students and faculty have developed a catalog of BIM uses and project implementation guidelines that have been adopted into the National BIM Standard-United States, version 2 (http://nationalbimstandard.org). Another important aspect of supporting numerous BIM uses is the development of open standards. The organization known as buildingSMART International (www.buildingsmart.org) provides a global platform for the development of such standards. Groups from a number of regional chapters around the world are generating information exchange standards that will soon have a profound impact on the ways in which we share model data with our clients and partners. Some of the latest developments are:
● IFC (Industry Foundation Classes) version 4
● COBie – Construction–Operations Building Information Exchange
● SPie – Specifiers’ Properties Information Exchange
● BCF – BIM Collaboration Format
● UK-based BIM Task Group (www.bimtaskgroup.org)
For a general overview of the approach to standardizing exchanges with information delivery manuals (IDMs) and model view definitions (MVDs), visit www.buildingsmart-tech.org/specifications.
When moving to the next step with BIM – be that better documentation, sustainable analysis, or facility management – you should look at your priorities through three different lenses:
● Visualize
● Analyze
● Strategize
Understanding these areas, specifically how they overlap within your firm, will help you define your implementation strategy for BIM tools and processes.
Creating documentation using BIM gives you the added advantage of being able to visualize the project in 3D. Although this was initially conceived as one of the “low-hanging fruits” of a BIM workflow, this benefit has led to an explosion of 3D graphics – perspectives, wire frames, cloud renderings, and animations – within the industry as a means to communicate design between stakeholders on a project.
This digital creation of the project has given us a variety of tools to communicate aspects of the project. It becomes “architecture in miniature,” and we can take the model and create a seemingly unlimited number of interior and exterior visualizations. The same model may be imported into a gaming engine for an interactive virtual experience. Clients no longer need to rely on the designer’s pre-established paths in a fly-through – they can virtually “walk” through the building at their own pace, exploring an endless variety of directions. The same model can then be turned into a physical manifestation either in part or in whole by the use of 3D printers (known as rapid prototyping), creating small models (Figure 1.4) in a fraction of the time it would take to build one by hand. Many types of visualization are currently possible with BIM.
Figure 1.4 An example of rapid prototyping using BIM data
Source: HOK
If we consider a complete spectrum of representations, from tabular data to 2D documentation and then to 3D visualization, tremendous opportunities exist to transform the notion of traditional design deliverables. Schedules give you instantaneous reports on component quantities and space usage, whereas plans, sections, and elevations afford you the flexibility to customize their display using the information embedded in the modeled elements. For example, the plan in Figure 1.5 shows how color fills can be automatically applied to illustrate space usage by department.
Figure 1.5 Even 2D views can evolve to illustrate and analyze spatial properties.
Expanding 2D documentation to include 3D imagery also gives you the ability to clearly communicate the intent of more complex designs. It may even have a positive effect on construction by transcending possible language barriers with illustrative documentation rather than cryptic details and notations. Figure 1.6 shows a basic example of a drawing sheet composed of both 2D and 3D views generated directly from the project model.
Figure 1.6 Construction documentation can begin to transform from 2D to 3D.
Source: HOK
The obvious benefit to creating a complete digital model of your building project is the ability to generate a wide variety of 3D images for presentation. These images are used to not only describe design intent but also to illustrate ideas about proportion, form, space, and functional relationships. The ease at which these kinds of views can be mass-produced makes the rendered perspective more of a commodity. In some instances, as shown in the left image of Figure 1.7, materiality may be removed to focus on the building form and element adjacencies. The same model is used again for a final photorealistic rendering, as shown in the right image of Figure 1.7.
