Understanding dimensions - Revit Tutorial

- [Instructor] When you first begin your wall layout, you'll often sketch in the approximate locations of the walls and then come back and manipulate those more precisely later. Now this is appropriate for early schematic design, but at some point you're going to need to start refining that layout to make everything more precise. Now there's a variety of ways we can do that, but the way that I want to demonstrate here is using dimensions. Now we have two kinds of dimensions, both temporary and permanent, and I'm going to illustrate both of them. Let's start with temporary dimensions. So let's start with what a temporary dimension is. I'm going to select this wall, right here in the middle of the screen, and notice that when I do, two dimensions will appear off to the left. Those are temporary dimensions. And they're called temporary because if you come over here and click an empty white space, that will de-select the wall, and the two temporary dimensions will disappear. So they're called temporary because they only display while something is selected. Now, notice that when I select that wall, the dimensions will automatically choose where their witness line locations will be. So in the lower dimension, it went out to this exterior wall and the upper dimension went over here to this horizontal wall. Now you have some control over where those locations are. But one of the easiest things you can do is change the level of zoom on screen. So I'm going to de-select that wall, put my mouse nearby that wall without clicking it, and roll the wheel to zoom in a little bit closer. Now notice that when I select that same wall, it will still see this wall up here because it's still a little bit of it showing onscreen, but notice in the other direction, that other wall was not visible, so it went to the grid line instead. So it will tend to favor walls over grids, but if there aren't any walls nearby in that direction, then it might switch over to grids or even other geometry. So that's going to be some of the behavior that you can expect to see with these temporary dimensions. Now, once a temporary dimension appears, let's say that we knew the distance from this grid line to this wall. Well, notice that you can put your mouse right on that number, click it, and that will activate that dimension. Once it's active, you can type in a new value such as eight. And when I press Enter, that will have the result of moving that wall. So it now moves that wall so that the new distance matches whatever you input, eight feet in this case. Now let's look at another example. Suppose I hold down my wheel and drag slightly to pan over to this location, and I'll select this wall next. Now, once again, notice that the temporary dimensions are favoring the nearby walls. Well, maybe I want to measure this wall off of this grid line. Now you certainly could zoom in again and use that trick I showed you a moment ago, but it turns out that you can actually adjust where those witness lines are located using these small little controls that appear on each of the witness lines. Now, all I have to do is click and hold down that little dot, and drag it until it highlights the preferred reference, like this grid line, and let go. That will move the temporary dimension, I can activate the number and type in the value I want. Now this time I want both feet and inches. Now to get feet, you've seen that just typing in a whole number and pressing Enter, Revit will interpret that as feet. But what about feet and inches? Well, one way that we can get feet and inches is to put in the number of feet, followed by a space bar, and then the number of inches. So I'm going to put in three, then space, and then four, and press Enter. That will move the wall, and notice that it interpreted that as three foot, four inches. All right, let's look at another example. So I'll pan down slightly, select this wall next, and if I'm satisfied with where the temporary dimensions are, I can edit them directly. But in this case, I want to measure this wall off of this wall. So once again, I could take this witness line grip, drag it, notice it will highlight that wall, I'll let go, I'll click right on that number, and this time I want to do four foot, eight inches. Well, another way that I can do feet and inches is to put in the number of feet, followed by the foot symbol, which is the single quote mark, and then the number of inches and press Enter. Now, both of them achieve the same thing, so it's entirely up to you which method you use. Now, as you can see, doing this with temporary dimensions is effective, but I'm having to move a lot of witness lines. So an alternative is to use permanent dimensions, which would allow you to set where you want the witness lines to be first, and then you can modify the positions as a second step. So let me demonstrate that with this small vestibule right here and here. So I'm going to click anywhere to de-select that wall, and then I'll switch over here to the permanent Aligned Dimension tool. So it's up here on the quick access toolbar, Aligned Dimension, I'll click that, and this creates a permanent dimension. Now let me show you what this looks like. What you want to do is click at least two witness lines. So I'm going to select this wall right here, move over and pick this wall next. Now notice that that starts to create the dimension but until you click a final point, you're not finished yet. Now a common mistake that folks make is they'll click again in the same spot. You don't want to do that because what you're actually in right now is witness line mode, and that means you're either adding or removing a witness line. And if you click in the same spot more than once, you're just going to remove the same witness line that you just added. So the trick is, you need to move into empty space, and make sure your final click is an empty white space. Let me do that again. I'm going to click right here on this wall, come up here and click on grid B, and then make sure that my final click is somewhere in empty space. Now I'll click the Modify tool to cancel the dimension command, and you'll see that those two dimensions remain on screen. So that's the difference between a temporary versus a permanent dimension. So these are actual dimension objects that are not only visible on screen and can be used to document your model, but if you actually select one of the elements that's being dimensioned, notice that that permanent dimension will activate. So let me show you that again, watch the number very carefully. I'll click an empty space, now it's not selected, now I'm going to select the wall. You see the change in the number. Now I'm going to click on the number, type in nine, and press Enter. Now common mistake that folks make, is they'll go right to the number, and they'll click it, and they'll end up with this dialogue right here. That's not the same thing at all. What this is, is the Edit Dimension text command. So it assumes that you want to override this dimension value and put in text there instead. I want to cancel that. So always remember to select the element that you want to move first, that activates the dimension, and then you can type in the number you want to move it. So let's do that again with another example. So let me come back up here, and choose the Aligned Dimension, and notice that it's defaulting to the center line of the walls. Now you could move your mouse slightly to one of the edges, press the tab key, and it would highlight that edge, and then you could click to set that witness line. But if you needed to set several witness lines on the face of the wall, instead of the center, you might not want to do all that tabbing. So alternatively, you can use this dropdown right here on the options bar and choose wall faces instead, and now instead of defaulting to the center lines, notice it's defaulting to the faces. And I'll pick this face, this one, and this one, notice that that's all one dimension right there, but don't forget that you have to click an empty white space to finish it. If you click again in one of those witness line locations, you'll just simply move that witness line. So let me do another one in this direction, click my modified tool to cancel. And then I'll come back and select this wall here. Now I'm going to zoom in slightly, pan down slightly, so we can get a better look at this. Watch all of these walls when I change the location of the selected wall. I'm going to make that 15 foot, eight and press Enter. And notice that all three of these walls stayed connected to the wall that I moved and resized accordingly. Now I want this wall selected and I want this corridor right here to be five feet. So I'll click right there, type in five, and press Enter, and notice that that moves that wall and keeps these two connected. Let's do this wall next, at nine foot 10. And then this one here, we can move with the temporary dimensions, but let me show you an alternative. If I come up here to the modify tab, there's a Move command right here. If I click that, notice that there's all these symbols that appear when you move your mouse around. So you've got a little X indicating intersections, you've got a little square indicating end points. So I want to start moving from the end point of this wall and then move up until I see a little triangle right there that indicates the midpoint of this wall. And by doing it that way, I don't have to figure out what the numerical value is and do the math, I can simply say, let's move this wall to the midpoint of this other wall. And now I know that it's bisecting that space into two equal spaces. So it's just another way to achieve a similar effect. Now let's do one more move command. I'll zoom out slightly, pan over, and let's go back to this wall right here. I'll go to the move command, and I'll start moving it from anywhere on the wall. Notice if you start moving in the direction you'd like to move, there's another dimension there. And you can edit that value directly. So if I just type in a number like one foot and press Enter, that will move that wall over exactly one foot. So regardless of which technique you use, you can see that you could start with a very simple layout of walls that's roughly sketched in approximately where you want it to go, and then using a combination of temporary dimensions, permanent dimensions, and commands like Move, you can fine tune the placement of all those walls and very quickly make a very precise building layout.