Changing mass/space dimensions using the Edit Length tool

Changing mass/space dimensions using the Edit Length tool

How to use the Edit Length tool to edit room size in a floor plan during a massing study.

Edit Length is used to set room dimensions. Unlike move, which works on portions of a split edge, edit Length modifies the entire connected dimension of a wall.

  1. Go to the Design tab and select the Edit Length tool.
  2. Hover on an edge, the edge is displayed in cyan, and the room is highlighted in yellow.
  3. Use the tab key to toggle between which of the connected rooms you want to edit, the highlighted edges indicate which room will be modified.
  4. Then simply input the new room dimension and the edge is elongated or shortened accordingly.



  1. Please note that Edit Length continues to work in the counterclockwise direction.
  2. Similar to move edge, extending an edge using edit Length will modify adjacent rooms as well, creating new edges where needed.

  1. If an edge is not highlighted on hover, it is because that edge is not editable, i.e., editing the edge may cause neighboring rooms to disappear or morph out of shape.
  2. Limits are set on Edit Length, so that rooms do not collapse into themselves, and do not criss cross. This limit, called the Length Constraint, is set to 10mm by default. If you input a dimension that would cause the room to collapse, or delete a neighboring room, the input is highlighted in red as an error, and is not processed. You can override the default value in Project Properties.


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