After you create a closed space with walls (preferably connected),
select room tool from tools bar and
double click inside the space formed by walls.

aaaaah [:)] , thank you !

Hi,
when you create rooms, you can have their area displayed.
see below in the screenshot:
https://www.computerbase.de/forum/attachments/1713763906403-png.1476649/

In the following screenshot you can see that area can also be displayed in the mode with walls, but how?
https://www.computerbase.de ...