Just making sure I have the right orientation...
I'm assuming the 'street facing front door' is on the bottom left, entering into the living room?
And is this map properly oriented north? If so, does that mean the corner on the bottom left of the house (where the front door is) is facing due west?
This is assuming my assumptions above are correct: It looks like you have a pretty good passive design. I don't see a lot of windows on the west side of the building, meaning you won't have an overly hot living room in the summer.
Remember that on the south facing windows, you are going to want awnings that block the summer sun, but lets in the winter light. You'll have to do some research to determine what the best angle is for your awnings.
It's hard to tell in your design, but the windows on the North side you are going to want to be as big as possible (for natural light).
Being Georgia, do you have any plans for some sort of central or whole house dehumidifier?
If you are planning on putting a second story in the future, what are your plans for the solar array? You are going to want to decide now if you want to build "around" the solar modules or remove them and put them on the second story roof.
You will also want to determine the pitch of the roof. Both the angle degrees, but also the direction. If your house is not going to be due south, you will have to make decisions about how you want the solar modules to face, or design the roof in such a way that some of it is southward facing.
If it helps, you can do a little research on the Kirsch Center. It is the Environmental Studies building at my school. It is completely designed to be a completely passive solar building. It incorporates some of the things I mentioned about the sides of the house.
Good luck, have fun and keep us updated!
