Using Building Information Modeling for Architectural Drawings

BIM tools can improve professional practice and drawing quality without any compromise
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Sponsored by Vectorworks
By Peter J. Arsenault, FAIA, NCARB, LEED AP

Design Applications of BIM

With all of the foregoing in mind, let’s look closer at the options during the early design phase of a project when using BIM. In particular, consider the need to sketch options and visualize the form and mass of a particular concept. One of the misconceptions held by some practitioners is that BIM isn’t suited for this early work because a BIM model needs to be very detailed. The fact of the matter is that BIM models can be schematic too, with very simple sketch style drawings or line renderings being displayed quickly and easily. If desired, shaded solids and shadow lines can be shown without any additional detail, much the way a hand-drawing massing study might be done. Of particular usefulness, an initial shape can be identified and then stretched or adjusted in three dimensions to create simple or intricate forms, solids, and surfaces. Additional detail can be added as needed to the form in a conceptual manner, all of which can later be used as the basis for creating drawings at any level. The overall point is that the designer is in control of the BIM model, the information put into it, and the visual representations of it at whatever level is appropriate and expedient to the immediate need.

Image courtesy of Vectorworks

During the early design stages of a project, BIM allows for multiple, simultaneous views for modeling and analyzing different concepts—even across multiple computer monitors.

When the need arises for a conceptual drawing to be shown in the manner of an artistic rendering, BIM offers choices here too. Once again, there is a misperception that only very detailed, photo-realistic renderings can come from BIM software. The reality is that a full range of artistic styles can be selected and used for representing a design. This can include 3-D images that display as sketch lines, shaded or unshaded solids, variously colored images, or painting styles. It is also possible to switch quickly and easily between different styles, including monochromatic, sepia tone, colored, and others.

Of course, if a fully detailed, photo-realistic rendering is desired, that can be done using the BIM software as well. The model just needs to have the appropriate level of detail added for the area being shown (i.e., exterior facades or interior spaces, etc.), and a fully developed rendering can be produced. This level of rendering can be inserted in photographs or have a rendered setting included with other features such as people, cars, trees, etc. all added as desired. In some cases, it is even possible to use software to take the image of a model and incorporate it directly into a photograph to show the size, scale, and/or texture of the design in the context of its setting. That is a particularly appealing for urban design projects, renovations, or designs where the site and setting are a significant design consideration.

The point here is that the BIM model and software are the source for all types of conceptual drawings, whether 2-D plans, elevations, or sections or 3-D visualizations for exterior or interior spaces. There is no need to leave the BIM program and use another software program—everything can be done internally. Then, as further design decisions are made and the model is updated, the visualizations will also update. This allows for multiple quick studies to be prepared and compared with input from building owners, public entities, and other design and construction professionals.

High-Quality Construction Documents Generated from BIM

Once a design concept is finalized, then the design development and construction document process begins. The Level of Development Specification can be useful here as a means to determine what information and attributes need to be added to the building objects/Model Elements to move them from generic items to the specific parts and pieces of the building at hand. Essentially, this is a process of going into the model and updating the information associated with each aspect of the elements. That can include changing from generic items to specific products with exact size and performance data or verifying connection and support details for different elements. Additional information for specifications, cost estimating, or project scheduling can also be added to items to allow for a full database to be realized and used. In this way, the design model is updated and becomes a full building information model with all of the relevant information captured for construction.

Customized Control of Documents

With the model updated, the design team needs to recognize that it now has everything needed in the model to create high-quality, coordinated 2-D drawings. Some architects have occasionally thought that this represents some type of a compromise on the quality of the drawings. In fact, BIM offers more options, versatility, and control over the drawing output. Everything from page layout to coordinated notes (including keyed notes linked to standard wording) down to the line weight and thickness of different items and graphics on the page can be selected. Understanding the flexibility and customization of BIM software means that drawing protocols can be set up within the BIM program that match national standards, in-house office procedures, or client-mandated requirements. And those options can be changed any time to suit differing project requirements, new client needs, interdisciplinary coordination, or updated standards.

Image courtesy of SPG Architects

Construction drawings can be fully customized within BIM software to use office drawing standards and control graphic representations, including views, details, textures, and line weights.

This customization of construction documents can be manifest in a number of different ways. Plans and elevations can all be generated directly from the geometric and dimensional information in the model and depicted at selected scales with any desired associated data displayed (i.e., labels, materials, etc.). Sections can be cut virtually anywhere and in multiple locations as needed. From a graphics standpoint, the legibility and clarity of the drawings can be controlled by assignment of drawing conventions to any of the BIM objects or drawing outputs.

Another time-saving and useful feature of most BIM programs is the ability to automatically generate schedules for doors, windows, partitions, finishes, etc. directly from data information contained in the model. Since all of the appropriate information or data is contained in the fully developed elements, it does not need to be input separately again. Instead, the designer selects which information to show and the software will populate the rows and columns of the schedules accordingly. In most cases, if something changes in the design, then the schedule will automatically update, thus serving as its own coordination check.

Document Coordination

Coordination between disciplines is a critical step for every project and is often cited as the number-one source of client complaints and claims. This is an area where BIM can be exceptionally helpful. While many consulting engineers may have their own specialty software that they prefer to use for design and calculations, they should also be able to produce outputs that can be entered directly into the main model in a fully integrated manner. In this way, the compatibility of systems and the space coordination of everything in the building can be reviewed, assessed, and adjusted as needed. That means structural information can be shown and coordinated with architectural information. Mechanical, electrical, and plumbing equipment, lines, and fixtures can be located and coordinated for clearances, access, or other design issues.

Image courtesy of Assael Architecture

Coordination between disciplines can readily occur using BIM for everything from title blocks and project information to coordination of building systems.

A big opportunity for improved coordination is found in the capability of the three-dimensional model to provide “clash detection” of different building objects/elements. This is a feature where the computer model alerts the designers if something like a beam, pipe, duct, or any other object is passing through the same space as another object, such as a different architectural, structural, or MEP element. Reviewing, assessing, and resolving these conditions in the computer model compared to doing so during construction is dramatically easier, takes less time, and is less costly to all involved.

 

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Originally published in Architectural Record

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