I have got 8 outlet boxes in my garage in my house that's being built. The wires in each of them look slightly different so I'm having a having a hard time confirming which will be outlets and which will be something else (what?).
Before getting into the specifics, I have to wonder why you don't ask your electrician and/or G.C.? They represent "The Horse's Mouth", so to speak; all we can do is guess at it. Better yet, if this house is being built for you, why are the locations and functions of the electrical devices an unknown in the first place? You should be telling them what you want where; then their job is to make that happen.
Anyway, taking a shot at it...
1 & 2 location
1 & 2 close up
One is light switch.... the other?
I'd guess that one box is for a general-lighting switch, and the other for the door-opener controls.
The one to the lower left of the image appears to be in a position where I'd expect a standard duplex outlet Given the pull-down stairway, the one high-up on the wall is probably for a switch to control the attic lights.
5 & 6 location
5 & 6 close up
One is power... the other is the door sensors?
Initially, I would have guessed that the round one is for the door opener, and the two single-gang boxes for two duplex outlets (possibly independently switched) to feed overhead lights. But the wires inside the right hand (as viewed in the pic) single-gang box do indeed appear to be low-voltage stuff, such as would be used to feed the switching signal from the control box shown in #1/#2 above (and, probably indirectly, an outside keypad) to the opener. Perhaps only one outlet is supposed to feed all the overhead lights?
7 location
7 close up
This is at tankless water heater. Pretty sure this is a standard outlet.
Sounds like a reasonable guess.. What is the third pipe for?
8 location
8 close up
Pretty sure this is the outlet for the sprinkler system. I'm most curious about this one because this is the one I'm for sure wanting to daisy-chain off of to put an outlet about 5' straight down for my workbench.
You may or may not be right about the intended function of this box. It's kind'a hard to tell from the pic where it is located in the garage. The wires inside appear to be standard Romex, with the outer jacket stripped off. So...?
As for daisy-chaining your workbench off this, I'd have to recommend against that. The Romex in that box looks pretty skinny (I'd guess AWG 14); which means it's good for AT MOST a 15 Amp breaker. You start plugging any semi-serious power tools into that, and you'll realize its shortcomings in a hurry. Plus, depending on the sprinkler control box you wind up with, you MIGHT be looking at having to re-program it ever time you trip the breaker -- not fun.
You're welcome. But like I said, it's only guesswork. Talk to your contractors.
I don't know what sort of work (if any) you intend to do in that garage. But were it me, I'd want AT LEAST three dedicated 20A circuits for tools and such (one of them more-or-less dedicated to the air compressor), plus at least one more for lighting. The lighting itself would be in three general categories:
1.) General-purpose "Walk Through" lighting, which would no doubt be controlled by switches near each door. You don't need a ton of light for this; but it should come on instantly (unlike some fluorescents, especially in cold weather), and be power-efficient even when rapidly cycled (again, unlike some fluorescents).
2.) The "Main" lighting for when you're actually trying to do something (such as work on your car, or whatever). "The more the better" tends to apply here; but the specifics are a topic worthy of their own discussion (and there have been MANY such discussions here already -- dig back into the older thereads).
3.) Dedicated "Task Lighting" at specific locations throughout the shop/garage, such as over your workbench (typically under the upper cabinets, if fitted), and at each semi-permanently installed power tool (such as your bench grinder, drill press, table saw, miter saw, etc.).
If you do plan to spend much time in the garage, you MAY also want to at least "rough in" lines for such things as a through-wall or window air conditioner and/or electric resistance heat of some sort.
Unfortunately, all of this stuff is the sort of thing you really want to plan out ahead of time, so that the wires can be run while the studs are open -- and it looks like we're a little late for that in your case.
Good luck!