Creating Advanced Families in Revit
When discussing the advanced applications that Autodesk® Revit® offers, the answers are varied. When discussing which advanced applications are important, the answers are equally varied. Each discipline has its own idea of which applications are more advanced—and more important—than others. Whatever discipline we work in, all can agree that Revit offers more capabilities, to more disciplines, on a broader scale … than any other software in the world. Regardless of discipline, Revit has something to offer—whether in Architecture, Engineering, Mechanical, Conceptual Modeling, and soon, Structural Steel Detailing.
STRUCTURAL STEEL DETAILING
The concept of detailing structural steel within Revit, and further defining the idea of BIM, is becoming increasingly popular. With the evolution of BIM, the need for “one model” by designers is becoming clearer with each project. The recent announcement of technology acquisition from Graitec, specifically its Advance Steel and Advance Concrete product lines, by Autodesk, underscores that need. While other programs exist that perform structural steel detailing, none perform it directly in the Revit environment, or even in the same language. Our hope would be that this acquisition would lead to it being done directly in the Revit environment, which is certainly possible. When fully realized, this development will poise Revit to become the undisputed “King of the Hill” of the AEC industry.
As the primary focus of our business, we utilize Revit for just that purpose. Granted, “out of the box” Revit currently doesn’t lend itself easily to this task (hence, the subject of this article); however, the vast depth of advanced Revit functions do allow for this, more easily than you might think.
Figure 1: Structural steel detailing in Revit
VARIETY OF SELECTION
As any detailer knows, no single connection will work everywhere on a project. The entire concept of detailing is creating whatever elements are needed to connect a structure, while ensuring those connections meet AISCand/or LRFD criteria. That being said, Revit is actually the perfect tool for this. The advanced parametric functions of Revit allow for the creation of complex connection families that can be parametrically controlled, through instance parameters and/or type parameters, depending on the specific need. There really isn’t a limitation on the type of family that can be constructed in Revit using advanced family building techniques.
There have been many books published on the subject of family construction. These are a great start, but the final determination on how well you are able to develop custom Revit families will be determined by the amount of “seat time” you can devote to the task. Family construction, for the novice, isn’t an easy task, but like anything in Revit or in life, practice makes perfect. Soon, you will be creating custom families that significantly reduce the amount of time spent in a project, increasing your profitability. Eventually, you will be creating custom families that allow you to offer services that no one else can offer, at prices no one else can touch, all because you put the seat time into the family creation task and developed a better mouse trap.
Figure 2: Structural connections in Revit
MORE THAN A CONNECTOR
Detailing is much more than connections, and so are Revit families. Detailing also includes Misc. Metals. Some of the examples of the families that can be created in-house include parametric roof frames, stair assemblies, railing assemblies, railing brackets, girder and joist stabilizer plates, saddles for wood beams, girder/beam haunches, joist bottom chord extensions, cap plates, base plates, shear plates, angle clips, just to name a few—and all fully parametric. The beauty of Revit’s family creation tool is that whatever the need is on a project, if can be constructed in Revit. As a fabricator, if I needed something made, I went to the shop, picked the proper steel item, and created whatever I needed. As a detailer, utilizing Revit, I create elements in the very same manner. The advanced capabilities of Revit really are a detailer’s dream.
Figure 3: Miscellaneous Metals in Revit
REVIT AS A PROTOTYPE TOOL
Revit is perfect as a rapid prototyping tool. In the engineering office, Revit can be used to rapidly assemble a rough structural frame for the engineer’s review. After this review, the frame can be finalized based on the in-house detailer’s use of Revit for structural steel detailing. This vital step in the design process is one that is often overlooked as unimportant, but the reality is, as we move toward full BIM implementation, the only logical placement choice for the structural detailer is in the engineer’s office. The ability to use a detailer to create the initial model, then connect up and detail that model after the engineer’s approval, is a currently unrealized cost savings in both time and rework.
Figure 4: Rapid prototyping in Revit
MORE THAN A DETAILING TOOL
How many of you have received the dreaded call, “Our equipment won’t fit”? Often, the need arises to coordinate equipment sizes and locations with building elements long before the equipment is installed. In some cases, buildings are constructed around equipment. With Revit, coordination of such elements is an easy task. Many times it is possible to simply download the manufacturer’s equipment model from Autodesk Seek or other online sites containing user-created Revit content.
Sometimes, however, the model you need simply doesn’t exist. Create it. Revit’s advanced modeling capabilities allow, literally, anything to be made. Whether it is a grain silo, hammer mill, mash cooker, or yeast tank...all of these elements are easily created in Revit. As these models are created they are easily inserted into the model, and coordination becomes a routine task. In the case of a well-known Tennessee distillery, grain silos were created, in the finished configuration, and moved around the site to ensure that the final positioning allowed for the proper ingress/egress of the dozens of tractor trailers that would be seen on a daily basis. Likewise, other equipment models were created and inserted into the model to ensure that all the elements fit properly, and even maintenance needs were addressed through this process.
Figure 5: Equipment coordination in Revit
MORE THAN A COORDINATION TOOL
Revit has also been used on historic preservation projects. Friends of Old Seven (www.friendsofoldseven.org) was founded in an effort to spearhead the rescue and preservation of the historic Seven Mile Bridge in Marathon, Florida. As part of this effort, Revit was utilized not only to reflect the current condition of the bridge, but also to show what the bridge could look like after the preservation efforts were complete. Considering that the bridge is more than 100 years old, every element created for this project was created completely from scratch, using Revit exclusively.
In addition to the existing 100+-year-old elements that had to be created for the project, the proposed final use model included elements that currently do not exist, but would have to be created for this project. In both cases, Revit easily handled the creation of these elements. One of the unique elements for this project was a scale transport train to traverse the bridge, carrying tourists along its historic route. Revit’s phenomenal family creation tools even allowed for this to be created. A word of caution: Don’t open Revit expecting to find a train creation tool, and you won’t find it in the Entourage folder either. This was a completely custom element in Revit; however, the fact that it CAN be created in Revit speaks to the unilateral, unparalleled power of Revit.
Figure 6: Historic preservation concepts in Revit
REVIT AS A SALES TOOL
As designers, we sometimes tend to forget that others either cannot, or do not, see our vision. Customers look to us to create their final vision. This is not an easy task; if it were, everyone would be a designer. The often overlooked visual representation tools afforded by Revit can be the perfect sales tool. It may take a bit more effort on the front end to create a conceptual model for a serious customer, but what better representation of your proposal than a model showing exactly what you are proposing?
The amount of time spent on the model is up to each designer, but the ability to show a rendered photograph of the finished product or even a walkthrough video will always tell more than any conversation can. The beauty of Revit is this: When you create a conceptual model, you have already started a working model. No more will you have to take a SketchUp model and recreate it in Revit; the conceptual model will take its place. No more will you have to convert a hand sketch to a model. That task has been eliminated and you may have gained a sale because of it.
Figure 7: Revit as a sales tool
The advanced capabilities of Revit are exhaustive. It is impossible to list all the individual functions that can be performed with Revit to make your project, or your daily workflow, stand out among the rest. Each advanced technique is applied based on what you are creating, how you are creating it, and your intended final application. To say that using advanced techniques is an art wouldn’t be an overstatement. In many ways it is art, and those who can artfully use the techniques are the ones who will stand out among the rest.
Followng are some images of projects created completely within the Revit environment, most of them using completely custom families. The final determination on which advanced level you operate in Revit will be determined by seat time and desire. For those who dare to be different, who dare to stand out among the competition, the time will be easily given. It requires a substantial dedication of passion, time, and effort, and while it may not be for everyone, Revit is.
Whether your project is a simple boat house, a complex hospital, a structural frame, or a visual representation, Revit is the “capable one.” Revit isn’t just everything to one discipline—it is everything to everyone. The only limitation is your imagination. If you can dream it, Revit can help you create it.
Figure 8: Unlimited creativity in Revit
Below are some examples of custom Revit connection families used during the structural detailing process. All of these families are fully parametric, allowing single families to be used multiple times within the same project, or on multiple projects. Whether it is a shear plate, connection bolt, or a modified joist family, all are easily created in the Revit environment.