Revit reference planes are datum planes used as guides, work planes, snap references, and the main control framework for parametric families. In the Family Editor, a reliable family usually starts with reference planes first, then dimensions and parameters, then geometry locked to those planes.
If you only need the command, press RP or go to Create > Datum > Reference Plane in the Family Editor. Draw the plane, name it, set the correct Is Reference value, then use dimensions, parameters, Align, and Lock to make the family flex correctly.
Quick answer: To create a reference plane in Revit, open a plan, elevation, section, or Family Editor view, press RP, draw the plane, select it, give it a clear Name, and set Is Reference in the Properties palette. Use Strong or named references for main family faces, Weak for secondary snap points, and Not a Reference for internal construction planes.
Best practice: build the reference plane framework before modeling. Then add dimensions and parameters, align geometry to the planes, lock it, and flex the family by changing Width, Depth, and Height.
What Is a Reference Plane in Revit?
A reference plane in Revit is a 2D datum plane used as a guide for placing, aligning, dimensioning, and constraining model geometry. In a project, reference planes help you define working planes and construction guides. In a family, they are the skeleton that controls how the family stretches, snaps, aligns, and responds to parameters.
For example, if you are building a simple parametric cube, you should not start by modeling the cube and then adding parameters to random faces. Start by creating reference planes for Left, Right, Front, Back, Bottom, and Top. Add dimensions between those planes, label the dimensions with parameters, and then lock the cube geometry to the planes.
This order matters. Autodesk recommends constraining family geometry to levels, reference planes, or reference lines instead of constraining directly between pieces of geometry. When geometry is locked to a parameter-driven reference framework, it is much less likely to break when the family size changes.
| Need | Use | Why |
|---|---|---|
| Control width, depth, height, or main faces | Reference planes | Stable framework for linear dimensions and family constraints. |
| Control rotation, angles, or endpoints | Reference lines | Reference lines are better for angular behavior because they have endpoints and can rotate. |
| Place geometry on a specific plane | Set Work Plane | Lets you choose the named reference plane where new geometry will be sketched. |
| Show a temporary construction guide | Reference plane | Easy to name, hide, show, and reuse as a work plane. |
How to Create a Reference Plane in Revit
The fastest way to create a Revit reference plane is with the RP shortcut. You can use the tool in the Family Editor from Create > Datum > Reference Plane. In a project environment, reference planes are also available from the work plane tools, depending on the active tab and context.
- Open the view where you want to draw the plane. For a family, start with the Ref. Level plan view.
- Press RP, or go to Create > Datum > Reference Plane.
- Click the first point and second point to draw the reference plane.
- Select the reference plane.
- In the Properties palette, enter a useful Name.
- Set Is Reference based on how the plane should behave when the family is loaded into a project.
Name the plane immediately. Names appear when you use Set Work Plane, and they make complex families easier to repair later. Good names are direct: Left, Right, Front, Back, Top, Bottom, Center Left/Right, Leg Offset, or Panel Thickness Control.
Reference Plane Shortcut and Related Shortcuts
The default Revit shortcut for Reference Plane is RP. These related shortcuts are useful while building a parametric family:
| Shortcut | Command | Use in this workflow |
|---|---|---|
| RP | Reference Plane | Draw control planes. |
| DI | Aligned Dimension | Dimension the distance between planes. |
| AL | Align | Align geometry to reference planes and lock it. |
| TR | Trim/Extend to Corner | Clean up extrusion sketch corners before finishing the form. |
To change or confirm shortcuts in your installation, open View > User Interface > Keyboard Shortcuts or use the KS shortcut.
Create the Reference Plane Framework
In this example, you will create a simple parametric cube. The same logic works for casework, furniture, equipment, facade panels, generic models, and many loadable families.
- Go to File > New > Family.
- Select the Generic Model template and click Open.
- In the plan view, draw four reference planes for the left, right, front, and back faces.
- Name each plane clearly.
- Set the main side planes to matching Is Reference values: Left, Right, Front, and Back.
- Switch to the Front elevation view.
- Draw two more planes for Bottom and Top.
- Set their Is Reference values to Bottom and Top.
A clean framework has only the planes you need. Too many exposed strong references can make snapping and alignment frustrating in projects. Use strong or named references only for the faces users should dimension or align to.
Set Is Reference Correctly
Is Reference controls whether a reference plane can be snapped to, dimensioned to, aligned to, or used for shape handles after the family is loaded into a project. Autodesk’s default for new reference planes is Weak Reference, but the default is not always the best choice.
| Is Reference value | Best use | Project behavior |
|---|---|---|
| Strong Reference | Important edges users should find quickly. | High priority for snapping, dimensioning, and Align. |
| Weak Reference | Secondary control planes. | Available, but lower priority. Users may need Tab to select it. |
| Not a Reference | Internal construction planes that should not be snapped to in projects. | Not visible as a project reference for snapping or dimensioning. |
| Left, Right, Front, Back, Top, Bottom, Center | Main family sides and origin-related controls. | Behaves like a strong named reference and helps dimensions remain meaningful when replacing similar families. |
For a simple cube family, use named references for the six main sides. For internal offsets, supports, clearances, or construction-only controls, use Weak Reference or Not a Reference depending on whether project users should be able to find them.
2026 compatibility note: Autodesk has reported a Revit 2025 issue where arrayed reference planes may not keep their original Is Reference value on copied array members. The support note says the issue is resolved in Revit 2027. If your office still maintains Revit 2025 family content, check arrayed reference planes manually before publishing the family.
Add Dimensions and Parameters
After the reference planes are in place, add dimensions between them. Then label the important dimensions with family parameters such as Width, Depth, and Height. The dimensions control the planes, and the planes control the geometry.
- Open the Ref. Level floor plan view.
- Press DI, or go to Annotate > Dimension > Aligned.
- Dimension between the left and right reference planes.
- Select the dimension and click Create Parameter from the Label Dimension control.
- Name the parameter Width.
- Repeat the process for the front and back planes and name the parameter Depth.
- Open the front elevation, dimension between bottom and top, and name that parameter Height.
Use EQ dimensions when you want a family to stay centered around its origin. For example, if the left and right planes should move equally away from the center plane, create an overall width dimension and use equal dimensions from the center reference plane to both sides. Learn how to change units in Revit if the values are appearing in the wrong unit format.
Build Geometry From Reference Planes
Once the framework flexes, create the family geometry. For this tutorial, use an extrusion to make a simple cube. The important part is not the cube itself. The important part is that every edge of the extrusion is aligned and locked to the reference planes.
- Open the Ref. Level floor plan view.
- Go to Create > Forms > Extrusion.
- In the Draw panel, choose Pick Lines.
- In the Options bar, turn on Lock.
- Pick the left, right, front, and back reference planes to create the extrusion boundary.
- Use TR if the magenta sketch lines need to be cleaned up at the corners.
- Click Finish Edit Mode.
Now lock the vertical behavior in elevation:
- Switch to the Front elevation view.
- Press AL, or go to Modify > Align.
- Select the Top reference plane, then select the top face or edge of the extrusion.
- Click the lock icon.
- Select the Bottom reference plane, then select the bottom face or edge of the extrusion.
- Click the lock icon.
- If the family should sit on the host level, align and lock the bottom plane to the Reference Level.
For more complex content, you can combine solid and void geometry after the reference framework is stable. Learn how to cut geometry in Revit if the family needs voids, openings, or cutouts.
Flex and Test the Family
Do not finish a parametric family until you have flexed it. Flexing means changing parameter values several times to confirm that the reference planes move correctly and the geometry follows them.
- Open Family Types.
- Change Width, Depth, and Height to larger and smaller values.
- Click Apply after each change.
- Watch for geometry that does not move, jumps to the wrong side, or creates a constraint warning.
- Load the family into a test project.
- Place an instance and open a 3D view.
- Select the family, open Type Properties or instance properties, and test the dimensions again.
If you need repeated parametric objects, the Array tool in Revit can create linear or radial repetitions. Just test arrays carefully inside families because constraints and reference settings can become harder to manage as the family gets more complex.
Show or Set a Reference Plane as the Work Plane
A named reference plane can be used as the active work plane. This is useful when you need to sketch an extrusion, blend, sweep, void, model line, or component on a specific plane instead of the default level.
- Go to Architecture or Create tab > Work Plane panel > Set.
- Choose Name from the Work Plane dialog.
- Select the reference plane name.
- Click OK.
- Click Show in the Work Plane panel if you need to confirm the active plane visually.
If the correct plane is not listed, select the reference plane and make sure it has a name. This is one reason naming planes early saves time.
Reference Planes vs Reference Lines
Reference planes and reference lines both help control family geometry, but they are not interchangeable. Use reference planes for most linear framework conditions. Use reference lines when the family needs angular control, rotation, defined endpoints, or a line-based work plane.
| Reference Plane | Reference Line |
|---|---|
| Best for width, depth, height, faces, offsets, and stable work planes. | Best for rotation, angular constraints, endpoints, and line-based control. |
| Acts like a plane that can be used for sketching and constraints. | Has a start point and end point, so it can define directional behavior. |
| Common in most parametric families. | Common for door swings, angled parts, rotating components, and adaptive behavior. |
For example, use reference planes to control the sides of a cabinet. Use a reference line if you need a door panel, bracket, or nested component to rotate around a hinge angle. For curved or path-based geometry, also review how to create sweeps in Revit.
Common Reference Plane Problems
Most reference plane issues come from missing names, wrong Is Reference values, unlocked geometry, or constraints placed directly on geometry instead of the reference framework.
| Problem | Likely cause | Fix |
|---|---|---|
| Family parameter changes but geometry does not move | Geometry is not locked to the controlled planes. | Use Align, select the plane first, select the geometry second, then lock. |
| Cannot snap or dimension to a family side in a project | The plane is set to Not a Reference or is only a weak/internal control. | Set main faces to Strong or named Is Reference values. |
| Too many references appear while aligning | Too many planes are exposed as strong references. | Keep only major faces strong; set internal planes to Weak or Not a Reference. |
| Family throws constraint warnings when flexed | Constraints are fighting each other or tied to unstable geometry faces. | Remove conflicting locks, constrain to reference planes or levels, and flex one parameter at a time. |
| The work plane list is confusing | Reference planes were left unnamed. | Name all important planes and use a consistent naming convention. |
A good troubleshooting rule is simple: if a parameter does not update the family, check whether the geometry is truly constrained to the reference planes controlled by that parameter. If snapping in the project feels wrong, check Is Reference.
Reference Plane Best Practices
- Build the framework first: place reference planes before geometry.
- Name important planes: names make Set Work Plane, Align, and future editing easier.
- Use the right Is Reference value: strong or named for main faces, weak for secondary references, not a reference for internal controls.
- Dimension the planes: do not leave control planes free if they should be part of the parametric behavior.
- Lock geometry to planes: use Align and Lock instead of relying on geometry faces.
- Flex early: test Width, Depth, Height, and any formulas before adding detailed geometry.
- Keep the family lightweight: model only the detail needed for its use, especially if the family will be repeated many times.
- Use reference lines for rotation: do not force reference planes to solve angular behavior they are not ideal for.
Reference planes are also useful outside family creation, but they are most valuable when they make the family predictable. A well-built family should be easy to place, dimension, align, and resize without opening the Family Editor again.
FAQ
What is the shortcut for Reference Plane in Revit?
The default Revit shortcut for Reference Plane is RP. In the Family Editor, it opens the Reference Plane tool from the Create tab.
Why are reference planes important in Revit families?
Reference planes create the control framework for a family. Dimensions and parameters move the planes, and locked geometry follows those planes, which makes the family more reliable when values change.
Should I use Strong Reference or Weak Reference?
Use Strong Reference or named side references for main faces that users should snap, align, or dimension to in a project. Use Weak Reference for secondary references that should be available but not dominant.
What does Not a Reference mean?
Not a Reference means the plane can still help build and constrain the family internally, but it will not be available as a snap or dimension reference when the family is placed in a project.
Why does my Revit family not change when I edit a parameter?
The most common reason is that the geometry is not locked to the reference planes controlled by the parameter. Align the geometry to the correct reference planes, lock it, and flex the family again.
Conclusion: To use reference planes correctly in Revit, create the planes first, name them, assign the right Is Reference values, dimension and label them with parameters, then lock geometry to the planes. That workflow gives you a family that can resize cleanly instead of a model that only looks correct at one size.
Mohamed Fakhry has helped thousands of architects and designers find their next project with step-by-step guidance on his blog, mashyo.com. About Mohamed
His journey began during his university years when he recognized the need for information-rich 3D models to accelerate learning and improve production processes. Now, Mohamed shares his expertise through Revit tutorials that are accessible to all.
