Just about everything we do is for GC's, and what we do directly for individuals we don't necessarily charge anything extra, just plan to make money as needed and the price may be higher than what we would typically charge a GC for square footage because of the extra time and care required in a home.
With GC's, we frequently are invited to bid a job with several GC's who are going after the same job. For instance, there's a "Bob's Burger Joint" and Swifty Construction, Hands-On Construction, and Foundational Construction are all bidding to get the job. They all have a set of prints, they all make them available to subs to get some preliminary pricing so that they can submit a bid to "Bob". Most of the time we just send the same price out to each of the GC's,
but if we know that Willy is going to be the superintendent for Swifty (Willy who is hard to get along with, doesn't have the other trades pick up their mess, turns a deaf ear to problems you bring to his attention, isn't real compassionate about things like lights and water, cares only about his schedule and not yours...), we may add a little on the bottom for the worries. Maybe Hands-On has been habitually late paying, falling into the dreaded 60-90 day payment list, it's worth our while to get a little extra out of the job if we are going to have to worry about pestering them for payment.
I don't want to be the guy to stop a GC from getting a job because of my number...wait...maybe I do

, but I do want to be fairly compensated for the difference in the quality of the experience when working for a GC who is less than helpful to my profit and overall sanity.