Back to Basics
In the past, tips and tricks have been written to assist in productivity. I want to take a different look at some of the basics such as problems we run into when modeling and what other disciplines can do to make integration with the structural model smoother.
The whole concept behind BIM is collaboration. That is the essence of what the programs were created around and the main idea at its core. All too often this idea seems to be lost, and we end up working in our own discipline’s bubble. We do whatever works for our own discipline and do not care how that affects other disciplines. Essentially we are living in a selfish BIM world.
Typically, being a structural engineering company means that we are sub-consultants to the architect. Often we use their titleblocks and some of their parameters, but we can only utilize these tools when they are implemented correctly.
I want to cover a few areas of multi-discipline collaboration that relate to the issues I run into, and then spend the rest of the article discussing tips that apply to Revit Structure exclusively.
Collaborate, Collaborate, Collaborate!
Not only is “collaborate” the idea behind BIM software such as Autodesk® Revit®−it’s even a toolbar in Revit.
Figure 1: The collaborate toolbar within Revit
When I receive a model from an architect to begin a new project, Copy/Monitor is one of the first tools I utilize. With this tool you are able to copy or monitor levels, grids, walls, and floors.
First let’s look at the Levels tab. I recommend copying/monitoring the main levels of the architectural model, such as first floor and second floor, just as they are. As far as a roof level is concerned, it really depends on what type of roof you are dealing with. Copy/monitoring has a nice feature that can offset your copied level from the level you are monitoring. This is helpful if you want your joist bearing level to be associated with the roof level of the architect. The benefit of copy/monitoring levels is that when you receive an updated model you will get a warning that the levels have moved. That way, you can review them and do what is needed on your end to adjust your model. You also have the option to add a suffix and prefix to the title.
Figure 2: The Copy/Monitor Levels tab
Next is the Grids tab. Not too much to this one beside the fact that you only want to have one set of grids in a project. It would be much too difficult to keep multiple sets of grids updated and matched throughout a project.
Figure 3: The Copy/Monitor Grids tab
Third is the Walls tab. This one I use frequently and specifically with regard to wall foundations. To create a wall foundation you need to have a wall available for hosting. There are multiple ways of doing this, from recreating the walls in the model, or simply copying them from the linked model to yours. I have found that using the Copy/Monitor tool for this task seems to accomplish what I want in a clean manner. Before copying and monitoring walls, make sure you set up your wall options under the Copy/Monitor tool. When you look at the tool you will see that it lists the original types. These are the walls that are contained in the linked architectural model. It also shows the new type, which is the wall that is going to be placed in your model.
There are two methods you can use here. The first is to decide up front which foundation walls you want underneath each wall of the architectural model, and set those in the New Type drop-down box. The issue with this tends to be that we haven’t always designed the walls when starting this process, so we may not have them sized yet.
The other method is to set the new type to “copy original type.” This will copy the wall sketch from the architectural model into your structural model. You can change these walls later on in the design process. It will create a warning saying that walls don’t match, but you are able to clear that warning and it won’t appear again. Also, when working with architects, ask them to either stop their walls at finish floor (0’-0”) or, if they have a brick veneer, to extend the walls to the extent of that veneer.
One nice feature recently introduced is the ability to extend a single layer of a wall sketch. We will then own everything from that point down. It tends to make our sections clean and is a good splitting point between what is structural and what is architectural. Often I get asked, “What about the duplicate walls?” and that is where worksets come into play. I will talk about those later in the article.
Figure 4: The Copy/Monitor Walls tab
Finally, the Floors tab. Honestly, this is one I do not use very often, simply because most floors placed by the architects we work with are just utilized for items that need a floor to host them and very rarely are the right thickness or design. Often they aren’t split around structural load bearing walls and very seldom are they sloped. I have found it easier to just recreate the floors to my liking. But that being said, if you work with an architect who does superb floors and you don’t need to recreate them, by all means use the Copy/Monitor tool.
Figure 5: The Copy/Monitor Floors tab
I have heard arguments from both sides of the fence when it comes to copy/monitor. I have heard people say they absolutely will not use it and I know of others who love it.
Why do I use it? One of the simplest reasons is for collaboration. When I receive a new model from an architect, I get an alert of the items that have changed that I have copy/monitored. By going through the list, I am able to easily adjust my model. I don’t have to go through and realign all walls to match the architect’s; it can be done through the coordination review dialog box. In this box you receive a list that shows you what category the item is under, what happened to that item, and what the result of that change will be. You are able to take actions such as postpone, reject, accept difference, or modify for that particular item. It will also highlight that item if you have a view open that the wall resides in, or you can click on “show” for Revit to find it in a view for you. As nice as it is to receive a write-up of changes, we all know that there are always changes that are missed. By utilizing this tool, often those changes are apparent.
Figure 6: The Coordination Review interface
Of course, with any tool there will always be some things that don’t work to our liking. One downside of using Copy/Monitor is that if a wall is completely deleted and recreated in an architectural model, your link will be broken. You can either tell Revit to delete that wall or you can go back in and choose the Monitor option. This associates that wall with the new one in the architectural model. For those who don’t use Copy/Monitor, I recommend giving it a try.
Worksets Work
Often, turning on worksets is nothing more than a means to an end, and that end is creating a central file for multiple users. Technically, yes, this is a use for worksets, but it can be so much more.
Figure 7: The Workset interface
I said in the previous section I would discuss the duplicate wall issue that is created when copy/monitoring walls. This is when I utilize worksets. I create a workset called “Copied Walls” and place all walls that I Copy/Monitor into that workset. When the architect receives my model, all he or she has to do is turn off the Copied Walls workset to eliminate the duplicates.
There are times I want to see the architect’s walls with my footings. As long as you don’t place your footings on the Copied Walls workset, you can turn off the Copied Walls workset. The foundations will still show up, looking as if they are placed on linked walls. Worksets also make it easier to turn off several instances of an item in the shortest procedure possible. I don’t know how many times I have gone to hide metal stud walls and have to click on every single wall, one at a time, to hide them because I am unable to hide the entire wall category. Had they been on a workset, it would be one click in that view.
The MEP discipline seems to have a good grasp of worksets and that is because of the context of their discipline. They will have mechanical, electrical, and plumbing all running through the same area, and although filters can be utilized, it is simpler to start with worksets. You can show what you want and easily turn off what you don’t. I also create a workset in my model called MEP and make sure that their model is on that workset. This gives me quick control over their model without having to unload or hide a bunch of items.
The one thing to keep in mind when utilizing worksets is to be careful when saving out a model for a sub-consultant. You can detach from your central file, but whatever you do, don’t click “Discard Worksets” in the next pop-up that comes after detaching. If you do that, it will revert to a non-workset model and everything will show up no matter what the settings were previously.
Another thing to keep in mind is you need to know what the current editable workset is when you are modeling. Verify at the bottom of the screen that you are in the workset you want to be modeling.
Titleblocks
Titleblocks. Every project has them, unless you have gone paperless (and if you have, kudos to you!). Being a sub-consultant we very rarely use our own titleblock and almost always utilize the architect’s titleblock. I have seen titleblocks that range from horrendous all the way to really well thought-out.
The first thing to remember is that titleblocks in Revit are not the titleblocks of AutoCAD®. There is intelligence in the Revit titleblocks that helps everyone if they utilize it. I don’t know about you, but nothing is more frustrating when a project gets to crunch time and you go to make a submission with revisions, only to realize that the titleblock isn’t smart. What should be a simple universal command to update doesn’t happen.
Use the revision schedule that is built into Revit titleblock templates. There is a reason the software’s developers created that schedule and it integrates very nicely with the revisions settings in Revit. It is even intelligent enough to add the revision when you add the revision clouds to the sheet.
Figure 8: The Titleblock Properties box
Speaking of adding clouds to the sheet to get the revisions to populate, I hope those reading this know that you can go under sheet properties and click on the Edit button next to Revisions on Sheet and add a revision to a titleblock. The only reason I bring this up is because I recently witnessed the smallest revision cloud ever on a sheet just so the titleblock revisions would populate.
Figure 9: The Edit Revisions box
Finally, with regard to titleblocks, if you are utilizing features in your titleblocks that make it smart and adding parameters that only matter to you, please let the sub-consultants know. If we don’t know that you have special parameters that populate your drawing list, based on some obscure numbering system, we won’t fill it out.
When creating a titleblock just remember it isn’t just to be an import of your AutoCAD titleblock, it can be SO much more!
Now Something Just for the Structural Group
Z-Direction offset is a topic about which many structural BIM technicians have opinions and these opinions vary widely. I personally only use them in regard to joists. Why? The main reason is that joists families come OTB with their connection points being at the top of the component. If you have spent any amount of time looking at joists you will know that typically joists sit on their seats and aren’t connected at their tops. This is where I utilize Z-Direction offset. I place my joists, whether attached to a certain plane or using 3D snap, and then change the Z-direction offset to the depth of the seat. This gives proper placement of the joists within the model. It will also give proper symbolic cutback when attaching to a beam or girder.
People sometimes suggest changing the actual joist family so that the connection point is at the bottom of the seat, but seat depths vary depending on loading and sloping, so that doesn’t solve the problem. I do not use it in regard to beams or girders because often they are tagged with elevation from a certain level, and Z-direction offset isn’t considered in that elevation tag. Also remember that if you change the Z-direction in the Properties box before placing the beam, that data will be applied to every new beam you add, so be careful. Of course, any tool can cause headaches if not applied properly, so finding the right balance of how you utilize those tools in your projects is key.
Figure 10: Joists utilizing Z-direction offset
Figure 11: The Properties box where you edit Z-direction
Even if you already know these tips and tricks, have no desire to use them, or have ones of your own, the main imperative is collaboration. No matter what we do, it needs to work for all parties involved. Otherwise, we go back into our bubble and ignore BIM and the collaboration that it encourages.
