Builder indicated that an air gap is required based on local code.
If it's required, then you will need to install one.
You will find area that don't use air gaps, or you will find un-inspected plumbing, but in your case I think it's pretty clear.

: Selecting kitchen sink for new house. Builder indicated that an air gap is required based on local code. Since an air gap is somewhat unsightly, is a high drain loop at 20 inches above the floor an acceptable alternative?