Message: A room has a negative ceiling height.

Reference Number: KB-00724
Last Modified: September 18, 2019

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors

Home Designer Professional or Home Designer Architectural or Home Designer Suite or Home Designer Interiors or Home Designer Essentials


When I work in one of my plan files, a message keeps stating,

"A room has a negative ceiling height. Any railings surrounding this room will not display in 3D."

What does this mean and how can I fix it?


This warning will display when a room has a ceiling height that is lower than its floor height.

For example, if a room on Floor 1 has an absolute Floor height of 0" and a Ceiling height of -12", the warning will appear.

To resolve this issue, locate the room with the problematic ceiling height and raise its height so that it is located above the room's floor.

To find the room and raise the ceiling height

  1. Open the plan in which you are encountering the warning message and select Window> Fill Window Building Only from the menu.

  2. Select a wall tool, such as the Straight Exterior Wall option, and draw a wall beside your main structure.

    • The program will find the problem room and highlight it, and the warning message will display.

    • With the Warning message box open, locate the room that is highlighted.

    • If need be, you can move the message box by clicking and dragging its title bar.

    • When you have identified the problem room, click OK to close the message box.

  3. If you do not see a room highlight, then the problem room may be located on a different floor.

    • Go Up One Floor  and/or Down One Floor  and repeat Step 2 until you locate the problem room.

  4. Click the Select Objects  button, then click in an empty space in the problem room to select it.

  5. With the room selected, click the Open Object  edit button. On the Structure panel of the Room Specification dialog:

    Structure panel of the Room Specification dialog

    • In the image above, notice that under Absolute Elevations, the height of the Ceiling is lower than that of the Floor.

    • Increase the value of the Ceiling so that it is equal or greater than the Floor.

    • Alternatively, you can decrease the value of the Floor so that it is lower than the Ceiling.

    • When you are finished, click OK to close the dialog and apply your change.

If more than one room in your plan is affected by this problem, it may be a good idea to reset all rooms to the default floor and ceiling heights.


To reset default floor and ceiling heights

  1. Select Edit> Reset to Defaults and in the Reset to Defaults dialog that displays:

    Reset to Defaults dialog
    • Click the radio button beside All Floors.

    • Check the boxes beside Floor Heights and Ceiling Heights.

    • Click OK to close the dialog and reset all rooms to the floor and ceiling values that are specified in the defaults.