Modifying Garage Floor and Stem Wall Heights

Reference Number: KB-01855
Last Modified: February 7, 2017

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


After naming my Garage room, the floor and ceiling height information changed.  Why does this happen?

Adjust foundation heights for stem walls and garage areas


When Auto Rebuild Foundation is turned on, naming a room as Garage will cause changes to the way the foundation is built under that room.

First, begin with creating a basic example plan, where you will be using all of the default settings for Floor 1 floor and ceiling heights, and for building the foundation.

To create the basic plan

  1. In a new plan file in floor plan view, select Build> Wall> Straight Exterior Wall , then click and drag out the walls to create a basic structure with attached garage, as shown in the image below.

    Once the main building and garage room have been created, the foundation is automatically created with the default stem wall and footing heights.
    If your foundation does not automatically generate, click Build> Floor> Build Foundation  and put a check in the Automatically Rebuild Foundation box and click OK.

    The floor and ceiling heights in the room that will be designated as the Garage, are still at the default for Floor 1.  The Floor Height is 0" and in our case, the Finished Ceiling Height is 107 5/8".

  2. To verify this information, use the Select Objects tool to click on the smaller room on Floor 1, which will become the Garage, then click on the Open Object edit button.

  3. In the Room Specification dialog, notice the values set on the Structure panel.

  4. Next, select the General panel, and use the Room Type drop down menu to select Garage and then hit OK.

    When the Room type is changed, the foundation is rebuilt to reflect these changes.

  5. Open  the room to specification once more and return to the Structure panel to see the changes.

  • The Stem Wall Top (C) Height value is added to the Absolute Elevations and is set to the height of the underside of the floor joists on Floor 1. The floor is changed to a slab and the slab is lowered 12" below the top of the stem wall. 

  • The Stem Wall (I) Height is set to 22 1/2".

  • The Floor Finish is set to 0" and the Floor Structure becomes a 4" concrete slab. 

  • Click OK to close the dialog for now.
  • Note: You may want to change the Stem Wall (I) height to meet your frost depth needs, however, before making any changes to the Structure settings in the Room Specification, you must first turn off Auto Rebuild Foundation.

    To create a Full Overview

    1. Select 3D> Create Perspective View> Perspective Full Overview  to generate a 3D image of the basic plan thus far.

    2. Once you have seen how the plan has been created, select File> Close View to close out of the camera view, returning you to floor plan view.

    To turn off Auto Rebuild Foundation

    1. Select Build> Floor> Build Foundation .

    2. In the Build Foundation dialog, remove the checkmark next to Automatically Rebuild Foundation, and click OK.

    3. In the New Floor dialog, choose Derive new Foundation from the 1st Floor plan and click OK again.

    4. Use the Select Objects tool to click within the Garage room on the Foundation level, and click on the Open Object edit button to display the Room Specification dialog.

    5. On the Structure panel, place a checkmark in the default box to set the Stem Wall height to 37 1/2"  (Default) to match the stem wall created for the main house.

      The slab remains in its original position, 12" below the top of the stem wall, but the footing is moved down to accommodate the increased stem wall height.

    6. You can raise or lower the slab by modifying the Floor To SWT (G) value.

      To create a 6" curb, or stem wall above the slab, set this value to 6".


      Click OK to apply this change and close the dialog.

    7. Finally, create another Full Overview  to see the change.