"Only the breaker would, if enough total current was passing." Well, sort of. Just to dispel any possible confusion: A GFI breaker implements two functions. The first is overcurrent protection. The breaker trips if the total current drawn from the circuit exceeds the breaker's rating. For branch circuits this is normally 15 or 20 amps. The more it exceeds the breaker's rating, the faster the breaker trips. The second is ground fault protection. The breaker trips if it detects that the current is asymmetrical across the power line. The amount of asymmetrical (ground fault) current that trips the GFI part of the breaker is MUCH lower than the current that trips the overcurrent part . (Confused yet?) To explain this second function: it's not 100% accurate to describe it this way, but it's easier (I hope) to understand if you think of the electricity as going out the hot side of the receptacle and coming back in the neutral side. The GFI monitors both of these. If the amount of current coming back is less than the amount going out, some of it must be "leaking" to ground. That leakage might be going through a person or animal, risking shock or electrocution. So when the GFI sees that, it instantly opens, shutting off the power. With most GFIs, an imbalance (fault current) of 5 milliamps (0.005 amps) is enough to cause a trip.

David Cary wrote, above: "I built with a tract builder and it was $40 to add an outlet at the beginning. That was a few years ago and I maybe added one or two that was not easy to do later." Hubs and I bought our tract home just under 30 years ago when it was in the framing stage. The builder gave all buyers the option to add additional electrical outlets, phone jacks, cable jacks, and ceiling fans (2 fans were standard - master bedroom and family room); as well as adding gas log lighters to the wood burning fireplaces (our model has two fireplaces - master bedroom and family room). The cost for each additional electrical outlet, phone jack, and/or cable jack was $40. Gas log lighters were $160 each. We added 2 gas log lighters, 3 electrical outlets (one of which is an outdoor outlet), 3 cable jacks, and 6 phone jacks. We also added two sets of security floodlights for the backyard (we have a very large backyard). I can't recall the exact cost for those, but I think it was $200+ each, which included the fixtures, bulbs, and the additional light switch inside the house to control them. The cost for those additions had to be paid in full in cash before the work would be done. At the time, 30 years ago, it seemed like it was a lot to hand over $1,200+ for those things. Now, 30 years later, it's an insignificant drop in the bucket, especially considering that those extras have made living in this house a lot easier/more convenient. As Greg_2015 said, above: "I'd suggest not looking at the individual prices of the modification to your plan. Look at the big picture number for the design change and decide if it's worth the price. If it isn't, don't do it. It doesn't matter what the itemized prices are."

Thank you all! To add some context, we are working with a custom builder and will have the architect draft our plans however, we get only two revisions upon the first draft. That is why I wanted to come in extra prepared. I'm sure our process is not like a truly custom home -- but I agree I want to leverage the expertise of the architect. Sounds like you're using the builder's "architect". I'm guessing the builder's "architect" is really a draftsman and not a LICENSED architect. Why do I say that? Because our builder basically had us work with his "architect" who turned out to be a draftsman, and a very poor one. Can you instead get your own architect? Even if the person you're using is licensed, chances are they will make it easiest for the builder and not what is best for you because he/she is "paid" by the builder. You bringing him/her your plans is not how a REAL architect works.

Very similar to our last home. When the plywood decking was down before flooring went in, I measured and drew island out on the floor and used a large cardboard box to put where the sofa with sofa table would go. Then DH and I marked under the "sofa" for the outlets. Your electrician should do a walk thru with your to discuss outlet and switch location before the rough-in. The large window, is there a view you want to face? Or the other wall of windows, does that open? View? With range wall, island and then table/chairs all in a row, I would want to break up the lines by doing the sofas or sofa/chairs in the opposite direction.