We just replaced our roof from comp to steel, and also replaced the sheathing. We have extended the eave about 3 feet, so that now the roof covers the entire staircase. (It had been dripping onto the center of the stairs). Our contractor only reinforced the eave about 4 feet when tying in the rafter extensions. Is this enough? Our friend says there should be more like 9 feet of reinforcement...

Immensely appreciated :)

I'd tend to agree with your friend without any further info. Did your contractor pull a permit for this job? What the framing approved by the building department. What does your structural engineer have to say aout this?

Double the cantilever is generally a good rule of thumb, an extension of 3 feet would require 9' sister rafters, tho' 8" would probably be enough. It is the weight of wet snow out there on the edge that you need to design for. That being said, is there a way you can provide support by extending the vertical supports on the outside of the stairs?

I've always been told that the maximum width for an unsupported cantilever is 2 feet. They would need some type of porch roof columns like WWPierre said.