Ground-fault circuit interruption (GFCI) receptacles, are not wired the same as regular duplex receptacles. In a standard duplex receptacle, both receptacles and all terminals are directly connected together (Unless modified). If one half of the receptacle is powered, then the other half is as well. With a GFCI receptacle there are LINE side terminals and LOAD side terminals, which are separated by an internal switching mechanism.
The wires feeding the circuit are connected to the LINE terminals, which supplies power to the device. If everything is wired correctly, there are not ground-faults, and the device is not tripped, then electricity is allowed to flow to the receptacles on the device and to the LOAD terminals. So if everything is functioning as it should, there should be be power at both the LINE and LOAD terminals. However, if the GFCI device is tripped, there will only be power at the LINE terminals.
Resetting the GFCI
If the GFCI has tripped, it can usually be reset simply by pressing the RESET button. If you press the RESET button and don't feel/hear a click and/or the button doesn't stay in, it means there is a problem and the internal mechanism is not allowing the GFCI to be reset. You can try pressing the TEST button, then pressing the RESET button again making sure you press the RESET button all the way in. If the device still will not reset, you'll have to try and determine the reason.
Why won't a GFCI device reset?
There are three reasons a GFCI device will not reset.
Wiring is wrong
If the GFCI device is not wired properly (LINE and LOAD reversed, hot and neutral reversed, etc.), the device will not allow a reset.
There is a ground-fault
Obviously, if there is a ground fault, the device will trip as soon as you try to reset it.
There is a problem with the device
If the device has gone bad, it will (should) not reset. Some devices will continue to hold, even if there is something wrong internally. However once they trip, they cannot be reset. Other devices will trip as soon as something internal dies, and will not reset. This is why monthly testing is suggested. If you press the TEST button, and then are unable to reset the device. You'll be made aware of a problem sooner, and can have it repaired (hopefully) before any damage is done.
Rewiring a new device
Before you begin, turn off the power at the fuse/breaker box and make sure it's off.
Locate the supply wire pair
There should be an ungrounded (hot) and grounded (neutral) conductor pair (likely as part of a cable assembly), that supplies power to the circuit. As it sounds like you've already located these, I won't go into detail as to how to locate them here (there are many other answers on the site that explain this procedure).
Terminate the supply wire pair
- Connect the bare/green grounding conductor to the green grounding screw on the receptacle (and to the box if required), and to any other bare/green grounding conductors.
- Connect the (white) grounded (neutral) conductor to the silver colored screw terminal labeled LINE on the device.
- Connect the (black) ungrounded (hot) conductor to the brass colored screw terminal labeled LINE on the device.
Terminate load side wires
If there are devices downstream that require GFCI protection, you'll have to connect the wires feeding those devices to the LOAD side terminals on the device.
- Connect the bare/green grounding conductor to the grounding conductors in the box.
- Connect the (white) grounded (neutral) conductor to the silver screw terminal labeled LOAD on the device.
- Connect the (black) ungrounded (hot) conductor to the brass screw terminal labeled LOAD on the device.
Set the device
Once all the wires are connected, install the device in the box using the mounting screws. Install the face plate, and turn the power back on.
- Press the RESET button.
- You should have power to both receptacles, and any downstream devices.
- Press the TEST button.
- You should no longer have power at the receptacles, or any downstream devices.
- Press the RESET button again.
- Power should be restored to the receptacles, and downstream devices.
This isn't "dangerous", but it can be inconvenient when your outlet goes dead and it's tricky to figure out where the GFCI reset button is.
On the other hand, this could be against your local electrical codes. For example, NEC 210.11(C)(3) states that your bathroom circuit may only power bathroom outlets. Note that there is an exception to this rule: When the circuit supplies one bathroom (i.e. isn't shared between bedrooms), other things (such as fans and lights) in the same bathroom can share the same circuit. Regardless, the mentioned situation is against the NEC code.
As to if the builder should modify this, I can't say. When in doubt, call your local building inspector.
Best Answer
Your friend is out of his league here
A GFCI outlet has two sets of terminals on it -- LINE terminals for the power IN as well as LOAD terminals that connect to the GFCI's protected hot and neutral in addition to that protected hot and neutral being provided to the GFCI's face receptacles. Hardwired applications can use what's called a "faceless" GFCI which just has the LOAD terminals instead of having both LOAD terminals and receptacles on the front; there are also GFCI circuit breakers that integrate ground-fault, short-circuit, and overcurrent protection into a standard circuit breaker package.
However, series GFCIs won't break anything
However, it is possible and permissible to connect two ground-fault trips in series -- nothing is harmed by that configuration, and it's more common than most people think. The only problem you cause by that is confusion as it is indeterminate (i.e. not defined) which GFCI will trip in response to a ground fault.