Autodesk Revit: Trimming and Extending Elements

In this Autodesk Revit tutorial I am going to show you how to use the suite of “Trim” tools. This suite is actually comprised of 3 different Trimming tools:-

  • Trim / Extend to Corner
  • Trim / Extend Single
  • Trim / Extend Multiple
We will cover all three variants in this tutorial. If you’d like to watch the video version of this tutorial, simply click in the box below…



The trimming tools can all be found contained in the drop-down for the “Trim” button, found on the Modify menu…..



Let’s start with the “Trim / Extend to Corner”. This tool is generally used when you have 2 elements hat don’t yet intersect- but you need them to be extended (or trimmed) and a neat junction formed between them. The two walls in the image below are a classic scenario when you’d want to use this tool…..



Switch to the “Modify” menu and select “Trim / Extend to Corner” from the “Trim” drop-down sub-menu……



All we need to do to use this tool is simply click on each of the elements that we wish to form the corner. So click on the first wall (1) and then click on the second wall (2). Note: Once you have selected the first element, Revit displays a preview (in a blue dashed line) of the junction that will be formed- you can see this in the image below…..



Once you have made the second selection the elements are extended or trimmed (as appropriate) and the junction is formed. In our scenario both elements needed to be extended in order to form the corner. This will not always be the case.



So we’ve seen how elements can be extended to form a corner. When might they need to be trimmed? Take the scenario below….




Let’s say we want these walls to come together and form a corner. In this scenario, a portion of wall (2) is going to be redundant. Lets say we want the corner to be like this…..



Again, we use the “Trim / Extend” to corner version of the tool. This time we have to very CAREFUL about where we actually click on the second element. The golden rule here is to “Click on the section of the element that you wish to KEEP”. If you take a look at the image above the one above (if that makes sense!), you need to click on the right hand wall at the point marked by the yellow reference (2).

Let’s move on to the “Trim / Extend Single” tool. Take the scenario below….

Here we simply wish to extend wall (1) so that it joins wall (2). We do not wish to trim wall (2) in any way. Go ahead and select “Trim / Extend Single” from the “Modify” menu……


With this tool the order of the 2 clicks is crucial.

  1. First click on the item you wish to extend “to”- this is number (1) in the image below.
  2. THEN click on the element that you wish to trim or extend- this is number (2) in the image below.


But what if we have multiple elements that we wish to trim and/or extend to a single element? No problem- we have a tool for that. Let’s take the scenario below…



We wish for walls (1), (2) and (3) to all form a neat junction with Wall (4).Go ahead and select “Trim / Extend Multiple” from the Trim drop-down sub-menu on the “Modify” main menu…..



First of all select the element you wish to trim / extend to. This is wall (1) in the image below…


At this point we could simply click on each of the remaining walls in turn. The top two walls would be extended and the bottom wall would be trimmed back. However, there is a quicker method: Simply draw a “crossing selection fence” around all 3 walls and they will all be trimmed / extended simultaneously. To do so, simply click  (and HOLD your mouse button) at point (2) in the above image. Now whilst holding your left mouser button) move you cursor to point (3). This creates a Selection Fence that picks up the 3 walls you wish to trim / extend. As soon as you release your mouse button (to accept the selection), Revit trims and extends the wall elements accordingly…..


Key Points

  • The Trim tool contains 3 variants
  • With the “Trim/Extend to Corner” tool- click on the parts of the elements you wish to KEEP
  • With the “Trim/Extend Multiple” tool- you can trim and/or extend multiple elements simultaneously be use of a Selection Fence.


Posted in Autodesk Revit.