Autodesk Revit: An introduction to Dimensions

In this Autodesk Revit tutorial I am going to give you an introduction to the use of the Dimension tools. If you’d like to watch the video version of this tutorial first, simply click in the box below…

 

 

If you are using Revit to produce “Construction Drawings” it is highly likely that you will need to dimension a number of your views. Dimensions convey the length,height and angle of elements, as well as their relationship to known “setting-out”points. Let’s take a really straightforward example…

 

 

 

Let’s say we need to show the total length  of the upper wall- i.e. the distance between the two red arrows. For this would we use an “Aligned Dimension”. In reality, you will use “Aligned” dimensions (approximately) 95% of the time when you are using Revit. That is why Autodesk chose to add “Aligned Dimensions” to the “Quick Access Toolbar” right out of the box.

 

 

 

 

All of the Dimension tools can be found on the “Annotate” menu. So switch to the “Annotate” menu (1) and then select “Aligned” (2) from the “Dimension” panel (2). Before we place the dimension, just take a look at the “Options Bar”….

 

 

 

Note how you can select the default location that Revit dimension walls from- i.e. to the Wall centrelines, Wall faces, etc. Make sure that “Wall faces” is selected. Hover your cursor over the exterior face of the wall on the left- at location (1) in the image below….

 

 

 

Click once at location (1) to place the start of the dimension. Move your cursor over the right of the view (2)- notice how the dimension line stretches out. Revit is ready for you to select the next (or final) dimension point.

 

 

 

 

Hover over the exterior face of the wall on the right (in the above image) and click at location (1) to dimension to this point. You you need to LOCATE the dimension line itself. Simply move your cursor to the location shown by (2) in the above image and click once to place (and finalise) the dimension.

 

 

 

Go ahead and select the dimension that we have just created. Let’s take a look at it’s various parts. With reference to the image above:-

  1. The Witness Line end grip: Use this to change the distance between the end of the “witness line” and the element being dimensioned.
  2. Witness Line location grip: Use this to drag the witness line to another element- i.e. dimension to a different element
  3. Constraint Padlock: Use this to creat a dimensional constraint: Lock the padlock to ALWAYS maintain the distance being dimensioned. This LOCKS the elements in place
  4. Value position grip: Use this to move the location of the value itself- a leader is created when you do this.
OK. Let’s now create a multi-part dimension string. Let’s dimension the same wall but this time pick up all the window openings as we go along. Again, use the “Aligned” dimension style. But this time just keep clicking on the various faces (window reveals) as you move along the wall. PLEASE NOTE: You need to create this in one operation- do NOT create this as a series of individual dimensions.

 

 

Go ahead and select the dimension that you just created.Again notice the padlock constraints (1)- one for each individual distance. Lock any of these padlock to constrain your model at that point. Also notice the “EQ” symbol (2). This stands for “Equal”. Notice how it currently has a red line through it- this tells us that all parts of the dimension string are NOT currently equal. Here’s the clever bit: Click on the “EQ” symbol and Revit will make all the divisions in the dimension equal- dragging the respective model elements with them. Use this to set out equally spaced components.

 

 

 

 

There is a MUCH EASIER method of dimensioning walls. Go ahead and select “Aligned Dimension” again. On the Options Bar activate the “Pick” drop-down menu and select “Entire Walls”….

 

 

 

 

Once you picked “Entire Walls” (1), click on the “Options” button (2) next to it….

 

 

 

 

The “Auto Dimension Options” panel now opens. You can now specify what Revit detects (and consequently dimensions) when you hover over walls. Go ahead and select Opening Widths (3), Intersecting Walls (4) and Intersecting Grids (5). Now just hover over the wall- it will highlight in blue to show you that it is selectable.

 

 

 

Go ahead and click on the wall to select it. Now simply move your cursor up the screen, away from the wall…

 

 

The wall (and all it’s openings) is dimensioned for you. All you need to do is make one more click in order to place the dimension down on the view. Go ahead and select the dimension (if it’s not currently selected). Click and drag on a “value grip”- to see how you can change the location of the values….

 

 

If you click on the value itself (1), the “Dimension Text” panel opens…

 

 

 

 

Using this panel you can display your custom text instead of the real value (2). You can also add additional text before, after, above and below the value (3). If you want to delete an individual segment in your dimension string, you can do so by hovering over the segment in question and using the “TAB” key to highlight it. Click to select it and then hit the “DELETE” key and it’s gone….

 

 

 

Although the “Aligned” dimension type is the most used, there are other dimension options….

 

 

 

 

  1. Aligned: We have already talked about this dimension type
  2. Linear: Used for dimensioning horizontally or vertically between two points. Very useful for setting-out points
  3. Angular: Dimension the angle between two references
  4. Radial: Dimension the radius of an arc
  5. Diameter: Dimension the diameter of a circle
  6. Arc Length: Dimension the length of an arc: BE CAREFUL to choose the correct face if it’s a curved wall!
  7. Spot Elevation: Records the height of a point in Elevation and Section views
  8. Spot Slope: Record the incline (as an angle OR ratio) of an element or line
  9. Spot Coordinate: Records the X and Y coordinates in plan views- great for setting-out points

 

You can fully customise the look & style of your dimensions. In order to do so, just click on the Panel Title “Dimensions”- see the above image. Doing so gives you access to all the various Dimension Type settings….

 

 

 

Remember: Dimensions are “Annotation Elements”. As such, they only exist in the vie in which they are created. If you need to replicate them in another view- choose “Duplicate with Detailing” when you duplicate the source view.

Key Points

  • Aligned Dimensions are arguably the most useful dimension type.
  • You can dimension floor plans VERY quickly using the “Auto Dimension” tool
  • Create you own Dimension Types in order to customise font, witness line arrows, etc
This tutorial is taken from "The Complete Beginner's Guide to Revit Architecture" FREE online course.
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Posted in Autodesk Revit.