First of all look at the GCs new home experience. Renovation and new construction are not the same.
Be a buyer. Interview 2 or 3 "reputable" new home builders and bid the job..of course include the GC you have a relationship with. This will really help to define the scope.
You can also interview additional architects to see if there are ideas that appeal to you more.
Full discussion with various professionals will raise questions, cause refinements and expand your understanding of the project.
DEFINE THE SCOPE! Include as much detail as possible so the bids are relevant.
As you interview and price the project with various builders, you will develop a much finer sense of the project and be able to manage it better because your expectations will be realistic.
Read blueprints. If you know how, excellent, if not learn prior to bids. They are the construction contract documents. Often a specification file can (should) be included that spells out details of product, performance and completion.
I'm sure you like your GC and architect, but it is incumbent that you approach the project as an informed buyer/investor. If you know the details of the project you can really expect to manage it well. There is a primary learning curve that relates to understanding codes, project sequence, and timely communication between the owner, GC, and subcontractors. Also, pay particular attention to schedule and lead times. You can make a lot more money when you are paying attention. Good luck!
