Roof of House and garage. Garage of right house on left.

Sorry, had to take a picture. It wouldn't let me upload my excel file.

civiccrazy:

Excuse my boldness, but every once in a while someone gives away that they have no business attempting the project they are inquiring about by the wording of their question(s). Unfortunately such is the case here.

Maybe you can find an experienced GC that will let you work on your own project. That will certainly be your best value.

The way that the new structure ties into the old, including the intersection of the rooflines for proper runoff is very important, and the way that the new laundry and bedroom area relate to each other and to the existing house both look problematic.

The laundry area seems to straddle the house and the garage and ignore the two existing rooflines and a major structural element, the corner post of the house in that area. As drawn there is nothing holding up that corner of the house and roof anymore.

I would consult a builder or architect for the proper planning even if you plan doing the work yourself.

So, you are contemplating adding a bedroom, bathroom and laundry room.

Your answer will lie in a trial and error method in composing elevations and deciding what aesthetically fits. They should include views from 3 sides as in at least 1 case, the roof can exceed the height of the garage.

The corner of the house can easily be supported by flush headers.

Gable is the most appealing, flat the least. Both from aesthetics and resale.