SketchUp Dynamic Components: 5 steps to build parametric components

SketchUp’s official help documentation explains how to set up Dynamic Components, including adding attributes, writing formulas, and constraining component parts so they do not scale. The documentation was updated on 29 September 2026. The feature is available only in SketchUp Pro. The examples below use the fence component from the documentation; the same approach can be adapted to architectural components whose dimensions need to be changed in a controlled way. The documentation does not specify a particular SketchUp version number.

1. Divide the component into child parts

First, create the component you want to make dynamic. If you do not want every part to scale in the same way, organize the component as child components or groups. In SketchUp’s example, the main Fence component consists of child components named Post, TopRail, BottomRail, and Picket. The main component and each child component have a unique name.

Placing the component at the origin of the axes can make it easier to configure the dynamic component. This is not a requirement; the official documentation presents it as a helpful suggestion. Naming the parts early in the modeling process also makes it easier to track which geometry each attribute controls.

2. Add attributes

Select the component and open the Component Attributes tool from the Dynamic Components toolbar. Alternatively, use Window > Component Attributes. In the fence example, right-click the component and select Dynamic Components > Component Attributes. The plus button opens a list of attributes you can add.

You can choose a predefined attribute for common behavior, or create a new one using the custom name option at the bottom of the list. A custom name must start with a letter and cannot contain spaces. Choosing a name that describes its function makes it easier to review the component settings later. Custom attribute names can be changed; predefined attribute names cannot.

Use the X, Y, and Z attributes for position; LenX, LenY, and LenZ for length; and RotX, RotY, and RotZ for rotation around an axis. Hidden, Copies, Copy, Name, Summary, Description, ItemCode, and Material are also among the attributes described in the documentation. Choose attributes based on the behavior you expect from the component; you do not need to add every attribute to every component.

3. Define values and formulas

You can type an attribute’s value directly into its box or enter a formula that begins with an equals sign. Opening the formula view lets you inspect the entire expression in the box. You can select and insert a Dynamic Component function from the list in the Functions tab. The Details menu also lets you choose whether a value is displayed to the user and whether it can be selected from a list.

In the fence example, the following expression is entered in the LenY field to fix the main component’s length along the Y axis:

=4

Child component values can be linked to the main component. For example, the following formula calculates the TopRail part’s Z position based on the height of the Fence component:

=Fence!LenZ-9

The X-axis length of the same part can be defined by subtracting the post’s length from the main component’s length:

=Fence!LenX-Post!LenX

The exclamation mark is used in a formula to refer to a value outside the current child component. In the examples in the documentation, lengths are in inches and angles are in degrees. Text in formulas is enclosed in quotation marks; use & to join text strings. After editing formula values, press Tab to accept the entry.

4. Constrain parts that should not change when scaled

In the Component Attributes window, expand the relevant child component and add position and size attributes. Entering a formula in a field and pressing Tab links that value to a defined value. The documentation notes that constrained values appear in black, while values that can change during scaling appear in light gray.

The fence example uses the following sample values to define the position and dimensions of the TopRail part. These are values for the example component in the help documentation, not general dimension recommendations.

Constrain the required position and size values for the other child components as well. The height of parts such as Picket can be defined proportionally to the fence’s overall height. Once you have finished configuring the component, close the window and test it with the Scale tool. You should be able to scale it along unconstrained axes while the defined values remain unchanged.

5. Position repeated parts with a formula

The Copies attribute specifies the number of copies to create; Copy represents the number of a particular copy in a formula. The documentation explains that copies are initially created at the same X, Y, and Z coordinates as the main component, so formulas can be used to position them. The following example spaces fence pickets along the X axis:

=5+Copy*(Fence!spacing+LenX)

In this expression, Copy represents the sequence number of each copy, while Fence!spacing refers to the spacing value in the Fence component. The formula calculates the position using the copy number and spacing value. Copies can be viewed in the Outliner, but their attribute-value pairs cannot be inspected individually in the Component Attributes window.

Use in architectural and visualization workflows

For furniture, railings, or facade modules that need frequent dimensional revisions, Dynamic Components let you define dimensions and relationships between parts instead of rebuilding the geometry each time. Modeling teams can use this approach when they need some component dimensions to change while keeping specific dimensions of posts, slats, or connectors fixed.

In practice, first decide which dimensions can change freely and which must remain fixed. Then define the relationships between the main component and its child parts using attributes and formulas. This approach can provide a structured setup, especially in projects where the same component will be used in different sizes; however, the results depend on defining formulas and constraints to suit the requirements. The sources do not specify any hardware requirements.

Common mistakes

• Using spaces in a custom attribute name or not starting the name with a letter.

• Omitting the exclamation mark in a formula when referring to a value in another component.

• Leaving a child component’s position or size values unconstrained when they should remain fixed during scaling.

• Using the example fence’s inch values without checking whether they suit your model.

• Looking for copy values in the Component Attributes window; copies are listed in the Outliner.

This guide is based on the Dynamic Components workflow in SketchUp’s help documentation, updated on 29 September 2026. The documentation states that the feature is available only in SketchUp Pro; it does not specify a particular SketchUp version number.