Architect.

This may not be a common or even popular response but since I have experience in both architecture and garden design (college degrees in both and a long practice as a professional garden designer), I will just throw it out there.

Unless you are intending to create some sort of overhead structure above the patio, what will a possible difference in roof styles have to do with how/where one constructs a patio? One has no relationship to the other! In fact, patios/decks/terraces and the like are often used to tie two disparate styles together. In which case, all you need is a landscape designer.....if that. No architect and no engineer....just someone with some background in masonry or patio construction

Perhaps there is more to this issue than you have described.....if so, please explain what that is and your thinking on why you need such a highly paid professional to approach this project. What sort of structural considerations do you think are involved here?

btw, unless it is a custom designed home, architects are rarely involved in residential design or construction. And even then, residential builders/designers are more likely involved in residential design and construction than licensed architects.

The question you need to ask the trades people you speak to is: Can you provide construction drawings to submit to the city for a building permit? A licensed building contractor is a good place to look for someone to tackle the problem and have the plans drawn.

If you want the covered patio to tie into the roof line, then yes, you need an architect. I think that's actually preferable to just adding a pergola since one of your goals is to make the original structure and the newer sections to feel like one house, not a series of add-ons.

If the pergola/patio cover is done correctly, it will look just fine.

I'd come out from the main portion just like this, and butt it up against the flat side.

Of course you don't have to do this exact type of wood pergola. you could do something more modern looking if you like.

coming off the main portion

If you want a completely covered patio, then you'd have to work something where both roofs are combined and joined. That's going to be a lot harder (and more expensive) to accomplish

personally, I'd do the patio cover w/the slatted wood top and work the supports into the new concrete you're going to pour. I think it will look great.

Pergola look, but not a free standing one, if that makes sense.

Thank you for your feedback! I so appreciate it. I live in Phoenix, however, and it’s getting hotter every year. I love the pergola look but the slats just don’t provide enough cover when it’s 118 outside. I had a 10x10 covered patio but even that was sunny for most of the day which is why I want to extend it out to cover most of the back of the house.

jennifer, we also get triple digits. I have those types of patio covers. This is one we did down the street on our rental house. basically the same as ours. there is no cloth covering on this one since they don't get the direct sun like we do down at our house.

on ours, what I do is put a double layer of the landscaping cloth over it. I have the gray one. it offers shade, but allows air to flow, and keeps out direct sun. And, it also keeps the house from getting really dark. If you have a solid cover back by the kitchen/dining area, its going to really cut back on the light that gets through. (but you say you've already had it, so maybe it's fine for you)

Definitely an architect, those are some challenging rooflines. Your fascias all look level so at least you have that going for you. You don't want to ruin a great MCM home (Arcadia?) with weird rooflines or a tacked-on structure.

IMO forget a roof cover and then the issue does not arise at all. Then get a landscape architect to design a nice patio in the size you like. use a pergola or I often just like umbrellas .