Aligned Dimensions

The most popular of all the Revit dimensions is the Aligned option. You'll use this type of dimension 75 percent of the time.

An aligned dimension in Revit enables you to place a dimension along an object at any angle. The resulting dimension aligns with the object being dimensioned. A linear dimension, in contrast, adds a dimension only at 0º, 90º, 180º, or 270º, regardless of the item's angle.

To add an aligned dimension, perform these steps:

1. Go to the Level 1 floor plan.
2. Zoom in on the east wing of the building.
3. On the Annotate tab, click the Aligned button, as shown in Figure 5.1.

   

4. On the Options bar are two drop‐down menus with some choices, as shown in Figure 5.2. Make sure Wall Faces is selected.
5. The next menu lets you pick individual references or entire walls. Select Entire Walls.

   

6. At the far right on the Options bar is an Options button, which allows you to make further choices when selecting the entire wall. Click the Options button.
7. In the Auto Dimension Options dialog box, select Intersecting Walls (see Figure 5.3). Don't select any other item. Click OK.

   

8. Zoom in on the north wall, as shown in Figure 5.4.
9. Pick (left‐click) the north exterior wall. Notice that the dimensions are completely filled out.
10. Pick a point (to place the dimension) approximately 8′ (2400 mm) above the north wall (see Figure 5.4).

    

11. In true Revit form, you're still in the command unless you tell Revit you don't want to be. In this case, click the Options button on the Options bar (the same one you clicked before).
12. Deselect the Intersecting Walls option in the Auto Dimension Options dialog box, and click OK.
13. Pick (left‐click) the same wall. You now have a dimension traveling the entire length of the building.
14. Move your cursor above the first dimension string you added. Notice that the dimension clicks when it gets directly above the first string.
15. When you see the dimension snap, pick that point (see Figure 5.5).

    

In many cases, you'll need the ability to pick two points to create a dimension. What a world it would be if everything were as easy as the dimension string you just added. Unfortunately, it isn't.

Creating Aligned Dimensions by Picking Points

Nine times out of ten, you'll be picking two points to create a dimension. This is usually quite simple in Revit—until you get into a situation where the walls are at an angle other than 90º. In a moment, you'll explore that issue, but for now, let's add some straight dimensions:

1. Zoom in on the northeast portion of the east wing, as shown in Figure 5.6.

   

2. On the Annotate tab, click the Aligned button if it isn't selected already.
3. On the Options bar, choose Individual References from the Pick menu, as shown previously in Figure 5.2, and do the following:
   1. Pick the outside face of the north wall marked 1 in Figure 5.6.
   2. Pick the horizontal wall that ties into the radial wall, marked 2 in Figure 5.6.
   3. Place the dimension about 8′ (2400 mm) to the right of the vertical wall, as shown in Figure 5.6.
4. With the Aligned Dimension command still running, do the following:
   1. Pick the outside face of the northern wall.
   2. Pick the centerline of the door, as shown in Figure 5.7, but don't press Esc or terminate the command.

      

   3. Pick the horizontal wall that ties into the radial wall, marked 3 in Figure 5.7.
   4. Pick a point inside (to the left of) the first dimension (see Figure 5.7). This places the dimension string and finalizes the session.

      The actual dimension values are blue. You also see a blue EQ icon with a slash through it (see Figure 5.7).

5. Click the blue EQ button, as shown in Figure 5.8. If the door was not exactly centered, this will force the door to move to an equal distance between the two walls. Notice also that the dimension string is actually one object. This is important.

   

6. Press Esc twice, or click Modify.

Sometimes you may want to display the dimensions rather than the EQ that Revit shows as a default. To do so, follow along:

1. Select the dimension.
2. Right‐click.
3. Choose EQ Display (this deselects the option), as shown in Figure 5.9.

The dimensions will now show an increment.

Pretty cool. I should address one last item involving aligned dimensions: How do you dimension along an angle?

Editing the Witness Line

Every dimension in Revit has its own grip points when selected. This is similar to most CAD applications. Two of these grips control the witness line. The witness line is the line “attached” to the item being dimensioned. Because you had to take this dimension from the core of the wall, the witness lines need to be dragged to the outside face of the brick. Follow these steps:

1. Select the angled dimension. The blue grips appear.
2. On the left side of the dimension, pick and hold the grip in the middle of the dimension line, as shown in Figure 5.13.
3. Drag the blue grip to the center of the wall.
4. Repeat the procedure for the other side.
5. To see the dimensions go to the original spots, delete the two lines you drew and drag the dimensions back using the small blue grip at the corners of the walls.

Trust me—this is worth practicing now before you get into a live situation. If you've already run into this, you know exactly what I mean.

Let's look at one more procedure for tweaking an aligned dimension: overriding a dimension's precision.

Overriding the Precision

When you dimension a wall at an angle such as this, the dimension usually comes out at an uneven increment. In most cases, you don't want to override every dimension's precision just to make this one, lone dimension read properly. In this situation, you want to turn to the dimension's Type Properties:

1. Select the angled dimension.
2. In the Properties dialog, click the Edit Type button, as shown in Figure 5.14.
3. Click the Duplicate button, as shown in Figure 5.15.
4. In the Name dialog box that opens, name the new dimension style Linear ‐ 3/32″ Arial ‐ 1/4″. For metric users, it's Linear ‐ 2 mm Arial‐10 mm. Click OK.
5. Scroll down to the Text category. Near the bottom is a Units Format row with a button that displays a sample increment. Click it.

   

   

6. In the Format dialog box (see Figure 5.16), deselect the Use Project Settings option.
7. Choose To The Nearest 1/4″ (To The Nearest 10) from the Rounding drop‐down menu (see Figure 5.16).
8. Click OK twice. Note the new value on the dimension at the angled wall.

Although aligned dimensions will bear the brunt of your dimensioning, there are plenty of other dimension types for you to use.

Linear Dimensions

Linear dimensions are used less frequently than most of the other dimensions. Unlike Autodesk® AutoCAD® software, in which linear dimensions are the go‐to dimensions, they're on the bench for most of the game in Revit. The best use for a linear dimension is to put a straight dimension across nonlinear (angled) geometry, as follows:

1. Zoom back in on the corridor area.
2. On the Annotate tab, click the Linear button. Notice that you can't select the entire wall. That option has been taken away. Instead, Revit requires you to pick a point.
3. Move your cursor over the inside corner at the bottom intersection of the corridor. Make sure you're exactly over the exterior intersection of the brick. You'll know you're there when the blue dot appears, as shown in Figure 5.17.
4. When you see the dot, pick the corner.
5. Pick the same spot on the other end of the wall, as shown in Figure 5.17. When you pick the second corner, the dimension follows your cursor in a straight direction.
6. Move your cursor to the left, approximately 8′ (2400 mm) past the first point you picked, and pick the third point to place the dimension (see Figure 5.17).

Aligned and linear dimensions are the two dimension styles that pertain to straight dimensioning. The next three dimension procedures add dimensions to angled and radial geometry.

Angular Dimensions

Angular dimensioning comes close to needing no introduction at all, but I'll introduce it anyway. Angular dimensions are used to calculate and record the angle between two items. These two items are usually walls. You'll add an angular dimension to your lovely corridor walls in the following steps:

1. Zoom back in on the corridor if you aren't there already.
2. On the Dimension panel, click the Angular button, as shown in Figure 5.18.

   

3. For the first wall, pick the finished, outside face of the angled corridor wall, which is marked 1 in Figure 5.18.
4. Pick the finished, outside face of the north corridor wall, marked 2 in Figure 5.18.
5. Move your cursor to the left about 8′ (2400 mm), and place the dimension marked 3 in Figure 5.18.
6. Press Esc.
7. Repeat the steps for the bottom of the corridor.
8. Add the rest of the dimensions, as shown in Figure 5.19. This completes the dimensioning of the corridor area.

   

If you would like to place the dimensions in different locations, feel free to do so.

The next set of dimensions pertains to radial geometry. You can finally get out of this corridor!

Radial Dimensions

Radial dimensions are used to, well, measure the radius of an item. You're lucky that Revit knows you're adding a radial dimension to a building component. This means the many different choices provided by a CAD application are taken away, leaving just the basics.

The following procedure will lead you through adding a radial dimension:

1. Zoom in on the east radial entry in the east wing.
2. On the Annotate tab, click the Radial button.
3. Pick the outside face of the radial wall, as shown in Figure 5.20.

   

4. Place the radial dimension somewhere that makes sense. If your model looks like Figure 5.20, you may proceed. If it doesn't, go back and try again.
5. Pan all the way to the west radial end of the west wing, as shown in Figure 5.21.
6. On the Annotate tab, click the Diameter button, as shown in Figure 5.21.
7. Dimension to the finished outside face of the brick, and place your dimension in a location similar to that shown in Figure 5.21.

If you're careful in how you add a radial dimension, you'll find this process quite simple. The next type of dimension, however, can be a little tricky.

Arc Length Dimensions

Measuring the length of an arc is a handy capability that was added back in the 2009 release. I have found the arc length dimension extremely useful in locating items such as windows along an arc. That is, in fact, what you need to do in the west wing of the building.

The following procedure will lead you through adding an arc length dimension:

1. Zoom in on the west radial entry of the west wing, as shown in Figure 5.22.

   

2. On the Annotate tab, click the Arc Length button, as shown at upper left in Figure 5.22.
3. Pick the finish face exterior face of the brick on the radial wall marked 1 in Figure 5.22.
4. Pick the centerline of the uppermost window in the radial wall, marked 2. The NO sign won't change, but you'll be able to pick the window centerline.
5. Pick a point along the exterior face of brick that runs along the vertical intersecting wall, marked 3 in Figure 5.22.
6. Pick a point at which to place the dimension, marked 4.

Let's try it again. This time the dimension will be taken from the first window (the one you just dimensioned) to the second window. The process is exactly the same:

1. On the Annotate tab, click the Arc Length button if you aren't still in the command.
2. Pick the exterior face of the brick along the radial wall.
3. Pick the first window's centerline again.
4. Pick the second window's centerline.
5. Pick a point to place the dimension (see Figure 5.23).

   

Now that you have experience adding dimensions to record the placement of items, it's time to see how you can physically use dimensions as a layout tool.

Constraining the Model

Choices you make early in the design process, such as constraining a model, can either greatly benefit or greatly undermine the project's flow. As you gain more experience using Revit, you'll start hearing the term overconstrained. This is a term for a model that has been constrained in so many places that any movement of the model forces multiple warnings and, in many cases, errors that can't be ignored.

Given that, how you choose to constrain your model is up to you. You'll learn how to constrain (and, of course, unconstrain) your model in this section, but deciding when and where to constrain your model will vary from project to project.

Using Dimensions to Move Objects

As I have mentioned before, you can't type over a dimension and cause the value in that dimension to be inaccurate. Revit does provide tools to get around this. When you add a dimension and select the object being dimensioned, the dimension turns blue. This is a temporary dimension, which can be edited. Consequently, the object being dimensioned will move.

The goal of this procedure is to select an item and modify the temporary dimension, in effect moving the object:

1. Zoom in on the left side of the west wing, as shown in Figure 5.37.
2. Select the door (see Figure 5.37). There is a blue dimension on each side of the door. These are temporary dimensions.
3. Pick the blue text in the lower temporary dimension (see Figure 5.37). The text might be obscured by the wall, but if you hover over it, it will activate, and then you can select it.

   

4. Type 6″ (150 mm). The door moves.
5. Press the Esc key to release the door.

This procedure used a temporary dimension that appeared when you selected the item. After you edited the dimension, it went away. In the next procedure, you'll add a permanent dimension and do the same thing:

1. On the Annotate tab, select the Aligned button.
2. Place a dimension between the door and the wall, as shown in Figure 5.38.

   

3. Press the Esc key twice.
4. Select the door shown in Figure 5.39. The dimension turns small and blue; it's ready to be modified.

   

5. When the dimension turns blue, select the text and type 6″ (150 mm) and press Enter. The door adjusts to the 6″ (150 mm) increment.
6. Press the Esc key, or click anywhere in open space to clear the selection.
7. Select the dimension.
8. There is a blue grip just underneath the text. Pick the grip and move the text out from between the extension lines, as shown in Figure 5.40. Revit places a leader (an arrow line extending from the model to your text) in the text.

The process of using dimensions to move objects takes some getting used to. The next procedure delves into making further modifications to dimensions and provides a nice fail‐safe procedure embedded within the Dimension Properties.

Using Dimension Text Overrides

Although I just told you that you can't override a dimension, the following steps get around that problem. In many cases, you may want text or, more commonly, a prefix or a suffix within a dimension. You can do all three in Revit:

1. Select the 6″ (150 mm) dimension.
2. The text turns blue. As you know, blue means this item is editable in Revit. Pick the text. You should see a dialog box like the one in Figure 5.41.
3. Under Dimension Value, click Replace With Text.
4. Type 1′–1″ (325 mm), and press Enter.
5. You get an Invalid Dimension Value message, as shown in Figure 5.42. Revit won't allow you to do such a foolish thing. Click Close.
6. In the Dimension Text dialog box, select Use Actual Value.

   

   

7. Under Suffix, type TYP., as shown in Figure 5.43.
8. Click OK.

Now, move the rest of the doors along this wall to a 6″ (150 mm) increment from the finished, inside face of the wall to the door opening. Also, dimension the floor plan as shown in Figure 5.44 and Figure 5.45.

Change the dimension of the southernmost wall to read 22′‐6″ (6859 mm) by selecting the wall and changing the temporary dimension as circled in Figure 5.45.

OK, one last thing and then we are done with dimensions. I'm not a big fan of the 0′ in front of a dimension that is under 1′‐0″ (305 mm). For example, 0′‐6″ (152 mm) is kind of a waste of space. Also, I like to reduce the width factor to .8. To do that, we need to look at the properties of the dimensions. Steps 1–3 can be ignored by metric users.

1. On the Manage tab, click Project Units, as shown in Figure 5.46.

   

2. Next to Length, click the button that says 1′‐5 11/32″, as shown in Figure 5.47.
3. Check Suppress 0 feet, and then click OK in both dialogs.
4. Select any aligned dimension and click Edit Type, as shown in Figure 5.48.

   

   

5. Scroll down to the Text category, and change Width Factor to .8, as shown in Figure 5.49.
6. Next to Units Format, click the button that reads 1′‐5 11/32″.
7. Uncheck Use Project Settings.
8. Change the Rounding setting to To The Nearest 1/4″.

Adding Leader Text

You can add text to a model by placing a leader first and then adding the text within the same command. Although in Revit you can add leaders to all text, you can choose to add text to a model with or without a leader.

The objective of the following steps is to place text with a leader:

1. On the Text panel of the Annotate tab, click the Text button.
2. On the Format panel, click the Two Segments button, as shown in Figure 5.53.
3. Pick a point near the radial wall, marked 1 in Figure 5.53.
4. Pick a second point similar to the point marked 2.
5. Pick a third point just to the right of the second, marked 3.
6. Type FULL HEIGHT RADIAL WALL.
7. Click an area outside the text.

Now that you can add text to a model, let's investigate how to modify the text after you add it. You'll begin with the arrowhead on the end of the leader.

Changing the Leader Type

It almost seems as though Revit uses the ugliest leader as a default, forcing you to change it immediately. The large arrowhead you saw in Figure 5.53 isn't the only one Revit provides—had that been the case, Revit might never have gotten off the ground!

To change the arrowhead that Revit uses with a text item, follow this procedure:

1. On the Text panel of the Annotate tab is a small arrow pointing down and to the right, as shown in Figure 5.54. Click it to open the Type Properties.
2. Change the Leader Arrowhead parameter to Arrow Filled 15 Degree, as shown in Figure 5.54.
3. Click OK. You've changed a type parameter.

That's a handsome‐looking arrowhead, as shown in Figure 5.54. The next item to address is how to modify the placement of text after you add it to the model.

Modifying the Text Placement

With any text item in Revit, you can select the text in your model, and you'll see grips for adjusting text: two grips on the text box, two on the leader, and a rotate icon.

Your next objective is to modify the text placement and to make the necessary adjustments:

1. Select the text you just added to the model.
2. Pick the right blue grip.
3. Stretch the text window to the left until it forces the text to wrap, as shown in Figure 5.55.

   Observe the rotate icon. You don't need to rotate the text here, but notice that it's there, for future reference.

   

4. Double‐click into the Full Height Radial Wall text box.
5. Notice that all of the tabs and panels change to edit the text.
6. Change the text to bold, as shown in Figure 5.56.

   

Now you can…

• add a multitude of different types of dimensions to your model simply by altering the options associated with the Dimension command
• equally constrain items in a model by adding a string of dimensions and clicking the EQ button
• use your dimensions as a layout tool, keeping the items constrained even after the dimension is deleted
• add text to a model by starting with either a leader or a paragraph of text
• change the text type and arrowhead type for leader text