The "Room from selection" button lets you create a room from the entity that you have selected in your project.
The perimeter of a room can be drawn using the various drawing functions such as line, polyline, arch, or others.
Once the geometric shape is closed, you can select the entire shape and click on the command Room from selection in the CAD tab of the Ribbon.
When drawing geometric shapes to become rooms, it is important that there are no disconnected vertices or overlapping lines. The width and height of the walls will automatically default to the preset values, however, they can be changed at any time using the dedicated commands (click here for more information).
This article is valid for the 2018 version and later.