@Ed Mayo
If you're going to GC it yourself you'll need a concrete contractor. You can just pick up the phone and call companies in your area.
For example when you call:
Hi my name is Ed Mayo. I have a residential project on the north side of Savannah, Georgia and I need a concrete contractor, who can I send then plans to at your shop?
Lisa from concrete shop:
Sure Ed. You can send then to John he does all the estimating. His email address is. John @concrete.com
John will usually call you back and ask more questions after he gets your plans. When do you want to start? He'll clarify and ask questions he had where your architect wasnt specific enough.
In Chicago, John will never call you back because John is incredibly busy with the work he already has. If you dont get a call back just keep calling. Trades are very very busy right now. They're not returning your call because of that most not because there is an issue with you or because they dont want to do your work.
Eventually John will give you a number. Concrete guys are tough and they usually run hand and hand with an excavator partner. They cant pour until you've dug. Georgia will have a different construction format than Chicago because of the weather and soil. I dont know know the rules regarding depth of pour out there.
Here a 2800 sq ft pour 42 inches deep which is below the frost line on 1 floor would be 80 to 90k foundation plus excavation. Which is a lot but I dont usually see 2800 sq ft on 1 floor either.
Hope this helps.