Gaining Ground in AEC

AutoCAD® MEP is becoming more prevalent in the BIM world, from all sides of the AEC industry. Though some groups, depending on their background, specific needs, or training, prefer the use of Autodesk® Revit® or other  software, there are a lot of reasons to use AutoCAD MEP 2012 instead. This article will outline some little (or not so little) known facts about this software and why it is rapidly becoming more accepted in the industry as an intelligent, parametric-based design tool for BIM industry leaders. This notion is replacing the rather dated attitude that AutoCAD MEP is a simple add-on to the infamous “AutoCAD Vanilla” base function that placed Autodesk on the map in the first place. Some are even naïve enough to put it in the same category as Express Tools when explaining its functionality in terms of how it sits on top of AutoCAD.

Because of Revit’s growing database-driven file collaboration process, many architects and structural firms have been moving toward using Revit for their process design needs. Revit Structure and Revit Architecture prove to be very useful (and very powerful) when working on a “stand-alone facet” type system. This means that architects and structural engineers typically will not need any other trades to complete their design documents and drawing sets, particularly for 3D models. The only things they must share is a coordinate system and a common grid.

These two trades are not typical in relation to others, as you could model the architectural end around only the structural model and the structural model either by itself or with the assistance of the Civil aspect. This is why there are Autodesk software packages aimed directly at only these trades—AutoCAD Architecture, Revit Structure, and Revit Architecture, for example.

These trades notwithstanding, there is no doubt that Revit MEP is powerful enough to take on multiple tasks within the MEP construction industry as it relates to BIM.

Granted, some industries are more adept to AutoCAD-driven software packages because of many factors. A lot of MEP, GC and General Construction AEC Contracting firms like using AutoCAD MEP because it is powerful enough to take on the hard-hitting and fast-paced role of the project while using intelligent parametrics with a massive growing library of information and models.

The newer releases (2010 and above) have been focusing more and more around BIM and 3D. These releases take cost, material, scheduling and many other factors to the next level by automating processes such as bills of material, panel and board schedules, quantity take-offs, and more. This, in collaboration with the aesthetically pleasing and not-too-detailed qualities of the 3D models from the stock libraries, are enough to make even the most old-school engineer want to learn AutoCAD MEP. Oh, and the learning curve is not as intense as others, either.

Ease of Use and Limited Training 

AutoCAD MEP is easily integrated into a team of engineers who most likely have been using vanilla AutoCAD for some time, since R14 or later. Because these engineers and designers are already accustomed to the AutoCAD platform and base commands, learning MEP is not as hefty as learning an entirely new piece of software such as Autodesk Inventor or Revit.

Not to say it is seamless, because it will take some time to adjust to the “mechanisms” that make this program tick. The Style Manager, for instance, is not as easy as, say, AutoCAD Architecture’s tool. And the Tool Palette, though fundamentally easy to view and navigate through, will take some getting used to. Once you understand the Workspaces, the Display Manager, Routing Preferences, Systems and others, you will know more than enough to be dangerous.

The standard AutoCAD commands are used for the basics. The more intense features that will move you from a basic user to an advanced user, such as adding custom parts to the library, creating MVParts to be used in collaboration with the stock catalog, using the content builder/editor to change the way that objects interact with each other, or the rules to which they abide, will all be achieved in time. At the very least, most users can begin to populate areas of a project with a very limited learning curve.

Progress Makes Perfect

In the past (pre-2008) AutoCAD MEP was called Autodesk Building Systems or ABS. ABS, though well ahead of its time in relation to other design software, didn’t appeal to certain people, most likely the decision makers who pushed other products to be their group’s standard modeling software for BIM.

In the past three years, though, AutoCAD MEP has made massive leaps to integrate the “information” aspect of BIM into this design software, rather than using their 3D library as just an add-on tool to vanilla AutoCAD. And, to be honest, it was little more than that in previous versions. There were a few “extras” that would compute air flow studies or turn-radius sketches, but at that time, MEP was a program that really could have been ran in AutoCAD using the “appload” command.

But time has passed and anyone who stuck with ABS and onward to AutoCAD MEP post 2007 would see that the growing software package was no longer a chunk of models and a few extras, but an entire catalog of mechanical, electrical, piping and plumbing parts that you could pull from a visual library, tweak how they react to other connected parts, adjust the rules and standards set forth in the style manager’s OSHA safety standards and trade-specific rules, and create your own parts for super-fast production of an assembly of parts that make up your entire drawing. Even the least experienced, entry-level drafter could 3D model a run of process plumbing without worrying about making an “illegal turn.” The software wouldn’t even let you draw it if it weren’t allowed in the installation world (for the most part).


Another great reason people choose AutoCAD MEP is because of its open-source “feel.” If your company uses non-traditional objects or tools that simply are not included in the “out-of-the-box” stock MEP Catalog, compile your own objects to add to it. You can even create an entire group of assemblies and MVParts to add to the tool palette and send it out to your entire team for use. They will then be able to see that group as an option in their now custom tool palette. This helps not only non-traditional and little-known trades, but also traditional trades, which get more realistic space-claim, population and cost analysis from their models. This is sure to make your company look great when Company Y is showing an extruded rectangle for cable tray and yours is showing the actual channels with rung ladders without bogging down the system as 3D solids.

Plays Well with Others

Many times you will see AEC construction firms opting for AutoCAD MEP (or another AutoCAD-based product) versus other comparable applications because of its interoperability with the project’s standards and guidelines set in place by the project’s general contractor or owner. Most of the time, the whole group—structural engineers included—must use software that is able to share information easily with the project team. Though Autodesk has been vigorously working on this angle for all of its software packages, such as Revit to AutoCAD, Inventor to Revit, AutoCAD to Navisworks, and so on, not every piece of software speaks fluently to the other just yet.

If the structural and architectural firms are using Revit, and the MEP trades are using AutoCAD-based platforms, the Revit users must conform to the AutoCAD users, rather than vice versa. Because of the popularity of AutoCAD applications, it is no doubt that the majority will be working to AutoCAD applications most of the time based on the “familiarity” compound outlined above.

When this happens, it doesn’t matter that their Revit model counterparts were so trim and small in size within Revit’s database-driven world, for when they export to an AutoCAD DWG, the size quadruples (at the very least). This is because it is turning intelligent objects into 3D solids on a very large scale. The larger and more complex the project, the more the file size multiplies. This is because each object is no longer an intelligent, stretchable parametric with many grips and object information, but rather a dumb, solid “3D chunk” that can be read in the AutoCAD world. One day, based on the rate that Autodesk has been working on interoperability between its own software applications, they will all speak to each other seamlessly by simply saving a Revit model as a DWG, while maintaining its objects’ intelligence. But until then, this is the way that we must operate.
With all of this being said, Revit MEP is by no means the “wrong” choice for subcontractors. Revit has proven itself to be a lone rider that can handle the strain of thousands upon thousands of components that make up a building.

I think that most people would agree, though, that Revit MEP is of great help internally and if the entire project’s subcontractors are using it globally. Otherwise, in order to send your 3D model out to the other subs who are using AutoCAD-based products for coordination and collision detection, you must “dumb it down”
and increase its file size. If all members of the team were using AutoCAD MEP, you would easily be able to identify other trades’ objects, keep their intelligence, keep the file size down on an overall compiled model, and impress the GC with how well each model interacts with another from the get-go.

AutoCAD MEP will continue to evolve just as Revit does. Until they can all get along perfectly, I will continue to choose AutoCAD MEP because of its ease of use, small learning curve for previous vanilla AutoCAD users, ease of interoperability with other Autodesk products, and open-source customizable interface.

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