Gambrel Roof and deck roof

[jghbuild]

The house itself is 2 stories, but the roof is the walls of the second story. All the upstairs walls are slanted to some degree and yes there are a few dormers and a few roof windows. So I think my rendering in the software is closer than the two story home shown in the response. The deck roof can not sit under the existing roof as shown in the suggested pictures. There isn't enough height to do that. A builder we spoke to wants to put it on top and we'd use a metal roof that would sit under the shingles. When I put a ceiling over the deck it messes up the whole roof. This house is 80+ years old and been remodeled twice. I'm sure nothing is the way it would be done today. Thanks for the suggestions though.
Jgh