Autodesk Revit: Model versus Detail Elements


A lot of the work you do in Revit is going to be constructing a virtual, 3D model of your design. At some point in this process, you are going to stop creating 3D geometry and you are going to to start enhancing it with 2D Detail elements.


This is a really crucial concept to grasp: And that is, not everything in your design is going to be modelled in 3D. There will be a percentage of the overall information package that is comprised of 2D Details. Let’s take a very simple model to explain this very important concept. In the image above, you can see a simple, single story building.

Unit Agenda

  1. The 3D Model and its’ 2D Detail
  2. There is only one Model
  3. 2D Details and Annotations are view-specific

The 3D Model and its’ 2D Detail


If we take a Section View through the eaves of our model, the image above shows what we will see. You can clearly make out the external wall and the pitched roof elements. You can see the various layers that make up the Wall and Roof Types respectively. What is clearly evident is that the junction between these two elements is far too simplistic. They just wouldn’t be constructed like that. It is at this point that we could stop adding any further 3D geometry to this area of the design and better describe our “Design Intent” by adding 2D Details on top of this view.



In the above image you can see that I have started to add some 2D Detail to my section view. All the elements shown in black are 2D Detail Elements that I have added- i.e. the brick and block units, the insulation in the cavity and the fascia/soffit boards. All the lines shown in a light grey are the edges of the original 3D geometrical elements of the model. And in essence, this is how we work in Revit: We create a basic 3D model and then we enhance and embellish it with 2D Details elements.

There is only one Model


If you take a look at the screen shot above, you will see that there are 4 open views- all showing different aspects of the model. It is imperative to understand that there is a single 3D model of your design proposal contained within each project. So in image above, we could change the position of a door, window, wall, etc; in any view and all the other views would update accordingly. This is because all of the above views are being generated (in real time) from the single model held in the database.

2D Details and Annotations are view-specific

So far in this Unit we have talked about a single, coordinated model and 2D Detail Elements. It is crucial to understand the primary difference between the two. And that is: All the Detail & Annotation Elements are “View Specific”. That means, they “only” exist in the view in which you create them. So going back to our external wall & Roof junction example above, the 2D Detail Elements I added (brick units, insulation, etc) ONLY exist in this particular view (the one I created them in. If I was to generate anther Section View a small distance along the wall, we would find that the view would be “bare”- i.e. devoid of the 2D Details.

Key Points

  1. We most certainly do not model ever last “nut and bolt” of our design in 3D
  2. We model (in 3D) to a certain level of detail and then add the missing information as 2D Detail Elements
  3. We add 2D Detail Elements to each view that we need to see them in
  4. Usually, we use the underlying model geometry as a “template” on which to create our 2D Details
This tutorial is taken from "The Complete Beginner's Guide to Revit Architecture" FREE online course.
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Posted in Autodesk Revit.