You can rotate not just one room, but even select and rotate multiple rooms simultaneously for more flexible designs.
Rotating a Single Room
To rotate a room:
Simply click on the room you want to adjust.
Then, hold the rotation button (shown in the screenshot) and use your mouse to rotate it smoothly.
Rotating Multiple Rooms
Need to rotate more than one room? No problem!
Select a room.
Then hold CTRL and click on the additional rooms you'd like to rotate.
Once selected, the process is the same: use the rotation button and your mouse to rotate all the chosen rooms together.