In this tutorial, you’ll follow a 13-step program to create a HEROIC LADDER family in Revit.

Why is this ladder heroic? Because you can control the angle and clearance height with simple parameters.

Like all great HEROIC FAMILIES 🦸, the result is fun and simple for the end-user, but there is some careful, complex work behind the scenes.

To achieve this, you must use three key features of Revit families: reference lines, work plane-based families and trigonometry. Let’s go through all the steps.

Watch the complete video tutorial:

1- Create a Regular, Parametric Ladder

The first step is simple: create a normal parametric ladder. You don’t have to worry about the angles for now. Of course, this assumes you have a basic understanding of reference planes, dimensions, labels, and extrusions. If not, check out this free pamphlet PDF guide covering basic family features.

The ladder rails are modeled with simple extrusions.

This is the plan view:

2- Create a Nested Family for the Rungs

Your best bet for the ladder rungs is to create a simple, nested family containing a single rung. It should look like this:

Load this nested family into the main ladder family. Place the nested family at a distance from the bottom of the ladder, just like this:

3- Create an Array for all the rungs

It’s time to use arrays. You will find the tool in the Modify tab. Make sure to use the Move to: Last option.

Then, place the element at the top. Align and lock it to the reference planes.

For now, you only have two rungs. Let’s fix this with formulas.

Select one of the elements in the array. Click on the long line with the number 2. In the options bar, select <Add parameter> under the Label dropdown menu.

Call the new parameter Number of rungs or Array.

4- Assign the Array Formula

In the family types menu, you must add a formula for the number of rungs to automatically adjust based on the height. The formula is:

(Height-(2*Height Offset))/254mm

In this case, 254mm is the average distance between rungs. It could be another parameter or a different value could be used if required.

Another option would be to add roundup before the formula, ensuring that the distance between rungs is never below 254mm. That would be:

roundup((Height-(2*Height Offset))/254mm)

Regardless of your choice, the family works, and the number of rungs automatically adjusts when the height is changed:

Put the final touches on this family, adding all material parameters, purging it, testing the values, etc.

5- Make the Family Work Plane-Based and Uncheck Always Vertical

Okay, here comes the juicy part of the tutorial. We’re going to nest the entire ladder in another family, where we can control the angle.

But first, there are a couple of final adjustments to make. In the instance properties of the ladder, you can see two parameters called Work Plane-Based and Always vertical.

Check the box for Work Plane-Based and uncheck the box for Always vertical:

This makes it possible to host this family on a reference line.

6- Create a New Family, Add Reference Planes

In the new family, you must create these reference planes, dimensions and label in the Left elevation:

Notice that we use simple a and b names for the dimensions. These can be renamed later, but using letters makes it more simple to write formulas.

Now, create another length parameter called c. It doesn’t have a label for now. You should have the a, b, and c length parameters created.

7- Create Reference Line, Add Angle Label

Whenever you think of an angle in a Revit family, you should think of Reference lines.

Create a reference line at the bottom left corner in the elevation view.

Align and lock the end point of the reference line to the reference planes. You must align twice, once for the horizontal ref. plane, and another time for the vertical ref. plane.

Finally, add an Angle label to the reference plane, just like this:

Try playing with the angle dimension. It should rotate around the reference planes intersection.

8- Place the Nested Ladder Family on the Reference Line Work Plane

Okay, this is another juicy part, especially if you are unfamiliar with work plane-based families. First, make sure the nested ladder is loaded into this family.

Go to a 3D view. Use the view cube to set the view of the family at the corner of the left and front sides. The only thing you should see in the view is the reference line.

Let’s place the ladder. In the project browser, you will see the nested family. Drag and drop it from the project browser to the 3D view.

Before you click to create the ladder, you must select the Place on Work Plane option in the ribbon:

Then, in the options bar, select Pick… in the Placement Plane dropdown menu.

Use the Pick a plane option.

In Revit, each reference line has 4 different work planes you can pick from—one at each extremity and two along the length of the line.

In our case, we want the equivalent of work plane 3 on the reference line. That is the horizontal reference plane, relative to the line’s length.

To properly select it, you might need to press tab once when your cursor is next to the reference line:

Overall, it should look like this when you pick the plane:

Now, you will see the preview of the ladder. At first, it will likely be in the wrong direction. Press spacebar to rotate it 90 degrees. Click to create the ladder.

The ladder is there, and hosted on the reference line! But it is.. upside down😅.

No problem, click on this icon to flip it.

Now, it should be in the right direction.

9- Align and Lock the Ladder

Go to the Left elevation view. Let’s align and lock the ladder so the bottom is at the corner of the reference plane’s intersection. Align and select the endpoint of the reference line. Lock it.

It should look like this:

Try to change the angle value. The ladder should follow along, and keep its origin.

10- Assign the Ladder’s Height to the C Parameter

The angle works. But you are not done. We want the user to control the clearance height (value b). But we must also assign the actual height of the ladder to parameter c.

First, select the nested ladder and go to the type properties. For the Ladder’s Height, associate length parameter c. Click on the small rectangle next to the height parameter.

Then, go to the type properties of the host family. Try playing around with the c value. The nested ladder should adjust.

The problem here is that the a and b dimensions aren’t linked to the ladder height at all!

You cannot “lock” a reference plane to geometry. Remember that in this case, we want the user to control the b value (clearance height) so the c value (ladder’s length) automatically adjusts.

There is only one solution possible, and it involves…

11- Use Trigonometry Formulas For a and c

Trigonometry!! 🤯🤯🤯

Remember in High School when you thought trigo was a complete waste of time? Wrong!!

The good news is that you don’t have to memorize any trigonometry formulas. I personally use a cheat sheet created by Brenton Wiberg from revitfamily.biz.

Here is an excerpt. In here, we want value c, and we have angle A and length b.

Therefore, the formula is b/cos(A).

We also need the a length. In this case, the formula is b*tan(A).

Enter these values in the formula. Of course, you might need to replace some of the letters with the parameter names. In our case, the A value is called Angle.

Have a look at your Left elevation. The reference planes are automatically positioned based on the trigonometry formulas. If you change the angle or b values, everything adjusts!

12- Rename The Length Parameters

You want your users to understand the family easily. It's possible that parameters called a, b, and c cause confusion in your team.

Well, no problem. In the type properties, you can select a parameter, click the pencil icon, and rename it. No need to adjust the formulas, that’s done automatically.

Here, we use more descriptive names for these parameters.

13- Associate Other Parameters, Test the family

The unique, juicy parts of the tutorial is over. But you might need to do more grunt work, such as associating other parameters from the nested ladder. Set the ladder width, rung dimensions, etc.

Add any missing reference planes.

Load the family into a project, and test it. How cool is that?

A key point here is that the end-user has a uber-simple experience. No need to understand what a work plane-based family, what is a reference line or what trigonometry formulas are used.

Think of it like an Apple product: there is complexity behind the scenes, but the user gets a nice, smooth product that is fast and easy to understand. My grandma could use this ladder family.

Want More Heroic Families?

The courses teach you how to create pleasant families that your entire team will love. You will understand all the subtleties, nuances, and special tricks of Revit’s family editor.

Want to learn how to create a giant parametric pegboard? What about a wood floor system? It’s all part of the course, which covers both theory and actual case studies from HEROIC FAMILIES used in high-level work environments.

The course includes:

▶   Videos: Watch 5h+ of video tutorials in 88 bite-sized lessons.

📖 eBook: Read the gorgeous 342 pages eBook PDF.

⚔️   Challenges: Test your skills with family creation challenges.

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