We are going to be doing a 300 sq. ft addtion to our home. Will basically make 2 bedrooms larger but also be expanding 2 bathrooms a bit by moving one wall about 2 feet. I am going to hire GC to do work. I want to defer some costs by doing the work myself. Once the concrete pad is poured and inside is framed i could take it from there. Would that be stepping on the General Contractor's toes too much?
As you have described this –YOU are the GC. GC’s typically oversee the entire job, and not just one or two elements.
A better approach is to (1) hire an architect to design and SPEC (very important) the entire addition. Those additional costs are well worth the expense as mistakes that happen mid-project are very, very expensive.
Then you can hire a masonry contractor to excavate and pour the foundation and slab, and a carpentry contractor to frame, side and roof the rest.
The architect can also help you by inspecting each contractor's work before payments are released.