Dormer cut extend to Roof edge

[nathaniel.mcmahon]

I'd like to extend a dormer cut to the bottom edge of the roof (which overhangs either side of the dormer)

The left hand dormer is showing a dormer cut 

The right hand is showing a roof edge sketch cut around the dormer. But internally we don't have a conventional dormer square cut in the roof. 

Trying to combine the two, revit doesn't like. 

Any ideas? 

[barthbradley]

I'm not clear on what you are asking, but if you can't there with the Dormer tool, what not just revise the Roof boundary to go around the Dormer Walls?  

[nathaniel.mcmahon]

Yes that's what I've done in the right hand example. But a boundary edge
isn't squared edge like the dormer cut (ie cuts the roof horizontally
instead of vertically). See the difference between the two.##- Please type
your reply above this line -##

[barthbradley · Accepted solution]

Redo the Dormer and select the correct surface. 

...or post the file.  

[nathaniel.mcmahon]

Great thanks! Hadn't realised I could select the roof as an Dormer cut edge.