A change or break in the roof slope is usually called a "transition". If the change is not very great, flexible shingle materials would only need some Ice & Water Shield flashing to prevent ice dam leaks where the roof becomes cold. If the change is great, Ice & Water Shield will probably be required over the entire porch roof under the shingles and metal counter flashing might be needed at the break line. If the porch roof is almost flat it will probably be roofed with a synthetic single-ply membrane that would carry up under the steep roof shingles. Obviously the greater the change is, the greater the cost will be.

Katieebs: A good design solves ALL design constraints so there's no having to choose between, for example, the plan and the exterior design as you are doing. Both would be accommodated. In lieu of copy and pasting the thing let me just point you here: http://ths.gardenweb.com/discussions/3178541/question-for-architectrunnerguy-or-others?n=24 Look at my post 11 posts down, not the one at the top with the colored drawing. Read the part about internet plans (spoiler: Very helpful) and the part about bags of $100 bills on the table. Sometimes I think I take the owners hard earned money more seriously than they do! I only point you there because since posting it, I've gotten some private notes, none of which I'll be doing the designing because they aren't local but all of which are looking to spend some six figure number of their hard earned money the best way possible in an endeavor in which there are no "do overs". Especially when that huge amount is weighed against the fee for a morning of conceptual design work by a creative thinker. So there has to be some interest there and may be you might too in getting someone creative that's local to look at improving the design. But good luck! EDIT: My crude red box was meant to illustrate a diagramitic concept (moving house FORWARD of garage), not moving those exact spaces IN the box forward while leaving the kitchen where it is. Sorry, that's me thinking conceptually!! No, the kitchen would relate to ALL other spaces the owner wishes. That's what separates great design from average design, both of which cost the same.

Wanting to add a hip roof porch over this door. One side supported by adjacent wall, other by a column. Need picture to send to builder. Having trouble visualizing. Thanks!

I don't think board and batten is the right style siding for your home. You've got too much going on with all the roof lines and uneven facade. What you've mocked up is appropriate and uniform, making the house look more uniform than it actually is. I love the mock up you did and I think the windows are appropriate for the style home. I wouldn't do a bow window, but a regular one. Bow windows are dated. I like your color scheme, but fear it won't look great with the brown roof. If the roof will need to be replaced anytime soon, then go for it. If not, you may want to look at other color options with a brown roof. A deep blue gray could look nice. This could be helpful in picking a color. https://www.kylieminteriors.ca/how-to-pick-exterior-paint-colours-in-5-easy-steps/