There’s a guy with a small backyard gable ADU that wants to add on to it. I’m not convinced he can deal with a complex roof line where the addition would need to be connected.

I’m thinking of just butting up the new addition against the existing one, instead of taking down the wall in-between and building a new roof for the whole thing.

Is this dumb? Two walls next to each other? 

The first photo is the before. He wants to put the addition on the slab in between the two structures. The second photo is kind of how I’m thinking it could look if I just smashed them together.