Building Design

Making the Switch — AutoCAD to Revit

1 Dec, 2010 By: Daniel Stine

Revit Tutorial: Before transitioning to Autodesk Revit, building design firms need to understand why, when, and how.

Many building design firms have made the switch to Autodesk Revit, either completely or for specific project types. However, many more firms have not yet made the jump. This article is meant to help those who have not ventured down the building information modeling (BIM) road yet, or who have the software but don't know what to do next.

To keep this article to the size of an article, rather than a book, only five fundamental questions will be discussed:

  • Why switch?
  • When is the right time to switch?
  • Who should be trained?
  • What content and template setup is needed?
  • What should be done when things go wrong?

This article will be presented as a two-part series. The first part will address the reasons to switch, the timing, and who to train; the second part will address the remaining topics.

This article refers solely to Revit; however, many if not most principles described here could apply to any BIM software transition. To be clear, however, when the acronym BIM is used in this article, it is referring to Revit.

Why Switch?

The answer to the question "Why switch?" can vary from one firm to another. However, generally speaking most building design firms can, or will be able to, benefit from Revit. The following list highlights a few of the primary reasons to make the switch:

  • Various municipal and private clients require BIM, and even clients who require AutoCAD files can still be accommodated when using Revit (except when they need specific AutoCAD blocks used). When firms start losing work because they are not utilizing BIM in their practice they should seriously begin to contemplate the switch.
  • Document coordination and accuracy is improved, especially when all disciplines are using Revit (Arch, ID, Struct, MEP).
    • It is very rewarding to be able to cut a section anywhere in the building and see that the ceilings, beams, bar joists, and ducts all fit within the plenum space.
    • When Revit is used properly, it is almost impossible to have a section, elevation, or detail reference point to the wrong drawing/sheet.
    • Because the 2D drawings are generated from a 3D model, all plans, elevations, and sections are synchronized. One does not need to remember to adjust other drawings after making a floor plan change. For example, moving a door in plan does not require making that same change in several other drawings (elevation, section, finish plan, code plan, etc.). Some notes might need to be adjusted, but nothing significant.

This high-quality Revit rendering is derived from the same model used to generate the floor plans, elevations, sections, and schedules. Notice how this view makes it easy to see how the various disciplines are coordinated.

  • High-quality presentation graphics become a byproduct of the construction documents (CD). In the AutoCAD workflow, the CDs are one effort and the renderings another. Often the project budget does not afford the additional effort required for a rendering. In Revit, it is easy to create a rendering or walkthrough animation of the model — which was created primarily for construction. Of course, it still takes additional time to set up colors, materials, and entourage. But quick renders for meetings and design critiques take virtually no time.

Kitchen rendering showing design intent, including cabinet layout, material finishes, and natural light for a given location and time of day and month.

  • Efficiencies in design and documentation can be increased when the proper preparations have been made to switch to Revit. Many mundane drafting steps are automated when using Revit. Add-ins can also help streamline energy, lighting, and structural analysis, as well as cost estimates and specification links. Of course the first few projects will likely take longer as staff learns to harness the power of BIM.

The Right Time to Switch

Once the decision to switch to Revit has been established, the next question that needs to be considered is, "When?"

Business considerations.
If a firm has not been selected for a project and the client has cited BIM as one of the deciding factors, company personnel will wish the switch was made last year. Some firms may work in a niche market and can comfortably wait a few years. Most others that are not currently using Revit fall somewhere between these two extremes.

Similarly, consulting firms that typically work with other design firms may need to jump into Revit if they want to continue collaborating with those who have made a commitment to BIM. Although Revit can link in AutoCAD files, doing so invalidates many of Revit's benefits and features, such as beams showing up in section or an outlet in an interior elevation. Note that some structural engineering firms do all their work in Revit, even if the architect is using AutoCAD to create 2D drawings.

Reflected Ceiling Plan (RPC) showing exposed ductwork when no ceiling exists to hide it.

Software considerations. Each year it becomes easier to make the switch from AutoCAD to Revit. Just a few years ago, each firm had to learn Revit on its own, from the ground up. Today, it is fairly easy to hire someone who has Revit experience so your firm has a head start on the transition. Another big factor that can help determine when to switch is the software's feature set. Autodesk comes out with an updated version of the software on an annual basis. For example, Revit MEP didn't introduce the ability to create accurate panel schedules until Revit MEP 2011. So whereas many electrical engineering firms didn't make the switch last year, when Revit could not do a basic code-compliant panel schedule, this year's feature set may entice them to do so.

Revit MEP 2011 has the ability to control what electrical load percentage of one or more electrical elements are calculated for a circuit or panel.

Hardware considerations. A high-quality workstation-grade computer is key to a smooth transition from AutoCAD to Revit. The switch can be made once the computers that will be running Revit have been evaluated and compared to Autodesk's published minimum system requirements. It is highly recommended that the "recommended" specifications be used, rather than the "minimum." Revit's performance is highly dependent on the speed of the processor (CPU), amount of RAM, and type of video card your computer has. The operating system (OS) should be 64-bit so it has access to more than 3 GB of RAM; Revit will automatically install as a 64-bit application when a 64-bit OS is found. Be sure to review the Graphics Hardware List provided on the Autodesk web site to ensure the card you have (or will be buying) is compatible with Revit. Also, be sure to update the graphics card driver regularly.

Tip: Check out an Autodesk whitepaper, "Model Performance Technical Note," for more detailed hardware recommendations.

Who to Train

After deciding when to make the switch, the next step is training. Jumping into BIM involves a lot more than just purchasing the software. Even though Autodesk makes both programs, Revit is fundamentally different from AutoCAD — so much so that even an AutoCAD expert could not just open the program and do anything productive.

In the past there was much debate about whether Revit could be used all the way through CDs. Now that it has been done thousands of times, the debate is over. Knowing this, there is no reason the first project cannot be completely done within Revit; there is no need to do a hybrid project where some work is done in AutoCAD. Revit has the ability to link in AutoCAD details from a firm's detail library, and then have callouts that point to them. Revit can create any new 2D details just like AutoCAD does, and most users prefer 2D drafting in Revit once they've used it for a few weeks.

The entire project team should be trained immediately prior to working on a project. This author (and trainer) believes the training should not involve the actual project. It is easier to focus on learning the software when working on fictitious projects and examples. When real projects are the basis for training, too much time is eaten up making the hundreds of decisions needed to get a project going.

Do not waste time training anyone who will not be using the software within a week or two of completing the training. It may be tempting to train the entire office or a large group of people to reduce training expenses; however, the folks who will not be using the software typically do not remember much of the training after a month of not using it, and those who will be using it right away may not get as much of the trainer's attention in a larger group setting.

The ideal option is an in-house trainer who can train startup design teams when needed and be available for just-in-time training and support afterward. To be able to effectively train and answer questions, this person should have experience working on previous projects. If such a person is not available in-house, there are two other options: Hire that person or contract the training through your reseller or a specialized consultant (such as Steve Stafford of AEC Advantage). When using an outside trainer, arrangements should be made to be able to ask questions and get replies in a timely manner. It is certainly more challenging to implement Revit if no one in the office has used Revit previously.

What the experts have to say…

Training is definitely one of the most important factors in a Revit implementation. The trick is to time the training with the project kick-off. Whether you use a local reseller in your area or have a trainer in-house, be sure the instructor covers the tools and techniques for building systems relevant to your project. The project team should actually help shape the curriculum and should include information about process changes. For example, coordinating and exchanging information between disciplines can set your productivity back if you are not prepared for some workflow changes. Lastly, realize that even when the formal training is finished, questions will arise. Have a plan to organize the team's questions and problems and address them over the duration of the project. Lunch-and-Learns and Q & A sessions with trainers, colleagues, or friends will progress everyone's skills. You'd be surprised at the number of people in the community that want to see you succeed.  — Andrew Johnson, LEED AP, BIM Manager,  DLR Group KKE

Finally, after all the basic training, at least one or two people should have advanced training on creating content. Not everyone needs to know how to do this. There is usually one person who enjoys doing this more technical stuff and would be efficient at creating content when needed. The next section delves deeper into what one can expect to create and develop before the first project.

Tip: A great way to get ongoing training and do some proactive problem solving is by following a few Revit blogs. Here are a few high-quality and fairly active blogs you may want to add to your favorites:


This wraps up Part 1 of the series; when we conclude with Part 2, I'll address content and template setup and what to do when things go awry.


About the Author: Daniel Stine

Daniel Stine

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Re: Making the Switch — AutoCAD to Revit
by: Arun Roy
December 3, 2010 - 8:00am
Dear Mr. Daniel Stine, I would like to sincerely thank you for sharing such a good article. I am a avid reader of Cadalyst Blog. I find this article helpful and informative one. While reading this article I have found an article titled "Diving into BIM-sphere: A Guide to Strategic Planning of Transitioning to BIM Process" in Architectural Evangelist Magazine which describes minutely how to transit from CAD-sphere to BIM-sphere? As your article is based one of the BIM-authoring tools (Revit), I would also suggest readers to read the same article. If these two articles are read carefully, the very need for transition from one platform to another will be clearly understood.Wish to read such nice articles in future too:-) Best:-)
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