Message: The main layer of existing walls will be moved to accommodate this wall type change.

Reference Number: KB-01079
Last Modified: August 21, 2023

The information in this article applies to:

Chief Architect Premier or Chief Architect InteriorsVertical SeparatorHome Designer Professional or Home Designer Architectural


When I edited the layers of one of my wall types, this message displayed:  

"Information: The main layer of existing walls will be moved to accommodate this wall type change."

What does it mean?


This warning indicates that you have changed the Main Layers section for one of  the wall types that exists in your current plan, and that walls will be moved to accommodate this change. Check to make sure this is what you really intended to do, and if not, follow the instructions below to restore the Main Layers.

Recall that in most circumstances, the Main Layers should include the structural layer of the wall, particularly when the wall is a framed type.

The Main Layers section determines many things, including:

  • Floor and ceiling platforms and automatically built foundation walls normally build to the outer edge of the Main Layers.

  • At intersections, walls join at the interior surfaces of their Main Layers.

  • Exterior walls on different floors are aligned by the exterior edges of their Main Layers.

  • Roof baselines are placed at the outer edge of the Main Layer when roofs are automatically generated.

  • Roof base lines and gable/roof lines that are manually drawn snap to the edge of this layer.

  • When wall framing is generated, stud depth is based on the thickness of each wall’s Main Layer.

  • By default, walls resize about the exterior surface of their Main Layer when their wall type or wall type definition is changed.

  • By default, Object Snaps locate the exterior surface of a wall’s Main Layer.

All of this information is reliant on the Main Layers section, so creating your wall type definitions accurately before creating your floor plan and specifying the Main Layers is very important.


If you want to be able to adjust the Main Layer of your walls without having them move, you first need to adjust your General Wall Defaults, then you can make modifications to the wall type definition.

To change the Default behavior for resizing walls*

*Applies to Chief Architect Premier, Chief Architect Interiors, and Home Designer Pro.

  1. Select Edit> Default Settings , expand the Walls category, highlight General Wall, then click Edit

  2. In the General Wall Details dialog, under the Resize About section, move the radio button to Outer Surface, then click OK.

    Selecting Outer Surface under the Resize About section in the General Wall Defaults dialog

    These radio buttons determine what part of a wall retains its position when its wall type or wall type definition is changed.

    The Resize About setting is also where any snap points will be located along a wall as it is drawn or connected to other walls, and is where a wall's length is measured.

  3. Now you can go in to your Wall Type Definitions dialog and modify the Main Layers for your wall types without it moving the outside surface of the walls.

To restore the Main Layer

  1. Select Build> Wall> Define Wall Types . to display the Wall Type Definitions dialog.

  2. Using the drop-down menu in the top left corner, select the wall type that you just modified which generated this warning.

  3. Use the Move Up and Move Down buttons to move layers until the Main Layers section has been restored.

  4. Click OK.