I believe auto roofs will build this roof, if set up correctly.
For the main roof, drag it up above the porch roof, then join them.
Raise the gable roof planes up -- I tried 40" I think. Join them to the porch roof.
Open a wedge shape in the main roof, then join the gable to it to open the gable to the inside.
Looks like you have some platform issues as well on the 2nd floor. Floor heights, no room definitions etc.
You may also need to modify the porch roof, depending on other settings.