Modifying Garage Floor and Stem Wall Heights

Reference Number: KB-01855 Last Updated: 12-05-2014 02:38 PM

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors or Chief Architect Lite


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


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, let's begin with creating a basic example plan, where we will be using all of the default settings for Floor 1 floor and ceiling heights and for building our foundation.

To create the basic plan

  1. First, launch Chief Architect and select New Plan to create a new plan, using the Default Style template.

  2. In the 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.

    The floor and ceiling heights in the room that we want to designate 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".

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

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

  5. Next, select the General panel, and use the Room Type drop down menu to select Garage.

    When we changed the Room type on the General panel of the Room specification to Garage, the foundation is rebuilt to reflect these changes.

  6. Return to the Structure panel after specifying the room as a Garage and notice 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 24".

  7. 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 Camera View> Full Overview  to generate a 3D image of our basic plan thus far.

  2. Once you have seen how the plan has been created, select File> Close 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 Auto 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 on the Garage room, then click on the Open Object edit button to again display the Room Specification dialog.

  5. On the Structure panel, observe that we have changed our Stem Wall height to 37 1/2" 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 (H) value.

    We wanted to have only a 6" ­curb, or stem wall above the slab so the value is changed to 6".


    Click OK to apply this change and close the dialog.

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

    Now that you understand this procedure, you can take the knowledge you have gained and apply it to your own designs.