I did on my model but i am not very happy with the results.
Revit roof unwanted valley.
This tool is located in the modify tab.
Get these project files and all advanced 1h courses.
Use it to extend the dormer roof to the main roof.
Edit the roof sketch double click the roof or select the roof and click modify roofs tabmode panel edit footprint or edit profile.
Use join unjoin roof tool.
To create a dormer model required walls and additional roof.
Hello i read here and there that the best way is to create roof valley with roof fascia.
Then follow these 2 steps.
Creating complex sloping roofs in revit 2014 roof junctions controlling roof slopes and levels.
I need to create that to be able to get in schedule lenght of it.
9 join roofs add opening to create dormer.
If you want to change the position of the roof use the properties palette to edit the base level and offset properties to change the position.
See hd version of video tutorial here.