For creating sloped roofs using the drawing.tool, the following steps can be followed:
Step 1: Go to the 2D view of your project and select the room over which you want to draw the sloped roof.
Step 2: Select the sloped roof icon to place the sloped roof over your space.
Step 3: Change type/properties of roof by clicking on the roof geometry and editing values from the panel on the right.
Complete Step-by-Step Workflow:
Alternative method using curves:
Create a level above the rooms that require a sloped roof
Using the Rectangle command under curves draw the roof footprint on this new level.
Select the newly created rectangle and click create sloped roof
A slope roof which can be further modified has been created over top all of the rooms under the define footprint.