...my question is couldn't tehe two circuits on the same phase with a common neutral cause the neutral to be overloaded? Most of my wiring is older - late 60's but should be fine in my opinion (BX w/bonding strip). The insulation on the wires to the kitchen light fixture were brittle and cracking, and the drywall around the box was singed. All I can assume is that the circuits sharing a neutral should be on different legs, but I'm not positive on that. I pulled the hots out of the panel and tried to trace them, but they're all over the place - Can anybody with experience tell me why this might have been done in the past? You are correct in concluding that two circuits on the same pole can cause overloading of the neutral. This could be an error dating back to the original panel installation or it could be a situation that was caused by a misguided "reorganization" of the breakers afterwards. Who knows? [Not that it's hugely important, but the proper term is "pole" or "leg" not "phase" in a 120/240 split-phase system. I'm also assuming that the neutral (in Bx cable!) is the same wire guage as the two hots.] As for the evidence of heat damage in the proximity of lighting fixtures, that's not an uncommon problem. Your wiring is probably rated for 60C degrees whereas many recent fixtures require wires with 90C insulation. When folks replace fixtures or choose an oversized lightbulb, this pesky detail is very often overlooked.

I know that a 12/3 feed is fine for 2 GFCI circuits as long as there's no shared neutral beyond the GFCIs, so my interpretation is that we're talking about an unusual case. jmvd20, pharkus: Now I see what you're getting at. Running 12/3 from box to box to box and alternating use of red and black works fine, as long as there's a GFCI receptacle at each outlet, and we only ever connect to the load terminals, and that hadn't occurred to me. We end up buying a lot of GFCI receptacles, but it's still probably cheaper than that 20 amp double-pole breaker. It sounded to me like the circuit was intending to use just two GFCI receptacles (one for each of the "red" and "black" circuits in the original 12/3 feed), and then continue supplying the two circuits with downstream non-GFCI receptacles through that single box to box to box 12/3 feed (i.e. shared neutral) throughout the kitchen. jong357 even says "...using 2 GFCI outlets, not breakers. One at the head of each run". This sounds unconventional to me (though I'm not a pro), but it would work just fine (and ONLY) with a double-pole breaker, if I'm correct, because of the shared neutral continuing beyond the GFCI protection. (Also in this case, wouldn't the GFCI receptacles need to be avoided because they would trip on any load because of the shared neutral beyond them?) I suppose the cheapest and simplest would be 12/3 to GFCI receptacles, with 12/2 following the split of the two circuits, even if the 12/2s just ran alongside one another, because the downstreams could just use regular receptacles. I appreciate the responses and attention to detail. It's hard to express this stuff clearly without pictures sometimes, and I know you guys know the theory and what works and what doesn't. I'll also shut up soon to avoid creating a monster thread!

Do you have a permit from the city? I've found the city inspectors to be an invaluable resource. I email them all the time to ask what should be. I've had SO many subcontractors tell me certain things are or aren't code, checked with the city, and been told something different. I have also had subcontractors make very serious mistakes, even if they came highly recommended and did parts of their jobs very well and took a lot of pride in their work. As a homeowner, you just have to know what to check for and what to ask for. One situation that comes to mind is the drywallers had not read the manufacturer's directions on our shower wallboard (DensShield/DensGuard) and had just installed it like any other drywall boards. This meant carefully countersinking all the screws in it. They install wallboard all day, every day, so they really though they knew all there was to it. But the shower wallboard we used is a relative new kind of material to the market, and the manufacturer specifically stated you should NOT countersink those screws because it punctures the waterproof membrane. So our shower waterproofing was like swiss cheese! The drywallers came out and redid it properly after I sent them the manufacturer's specs.

- I haven't seen a great need for quad receptacles in residential, other than a tv/gaming area or office desk - maybe a duplex next to a USB in some rooms. Have you taken stock of how many appliances you will have continuously plugged in at one receptacle? Realize that for a tv/gaming or office area, if you do not have surge protection at the breaker then a surge strip should be used, so a duplex is adequate. In a bathroom, for safety, curling irons, hair dryers, etc should not be left plugged in when they are not in use. In a kitchen, code requires receptacles within 24", so you probably don't have enough counter to have that many appliances sitting out. Otherwise, placement of duplex receptacles within 6' is usually adequate, with adjusted placement taken like behind the bed for each nightstand or up high for a wall mount tv. And if chargers/transformers are taking valuable 'plug' space, you can use receptacles with USB ports, they even have some with a USB at the same time as having 2 'plugs' on a duplex. - LED is technically low voltage. For under cabinet lighting, a receptacle inside a cabinet is usually the better choice if you do not know the exact fixture type, as it will hide either the transformer or cord plug in a direct-wire fixture. There are other means, but that is the most value-oriented option which matches a value-oriented kitchen. - Bathroom: Don't understand where "punching hole" would occur. Typically a receptacle is placed on the side out of the way. If you have a long vanity, you can place them on the back wall, but you then have to coordinate mirror and backsplash, and better to offset single sinks or place the receptacle between doubles. If your vanity is short, a back wall receptacle is worse as you drape over the sink. There is no disadvantage to having a cord strung to the side wall. If you plan on storing small plugged-in devices in a mirror cabinet (shaver, toothbrush), there are some available with interior receptacles so no need to jerry-rig holes. Panel: You are required to have min 2 SABC circuits, and once you factor in separate for ref, micro, disposal, etc, it takes a lot of space. Solar: Not sure what you are asking, but 1 panel would not provide the KW needed for much of anything. - Lighting plan: Bedroom2 recessed probably won't flank the bed (Master ok). Hallway needs 3 fixtures. Tub should have a combo exhaust/light just outside the footprint (again value-oriented). Dining would suggest a chandelier to make table permanent, recessed if not sure where you want it. Kitchen don't need center mount, recessed too close to Living. Living lay out furniture first. - Exterior: That's a lot of fixtures. Also, cameras would need either PoE or coax, and probably would not coincide with where every light fixture would be needed.