I'm trying to plan ahead for an electrical project on my basement. New ceiling lights (recessed and not), corresponding switches and some new outlets. I put a drawing together and I was wondering if I could use your guys' help in figuring out if I'm looking at the project from the right angle and if it's a good approach. Can you take a look at the plan and share any thoughts you might have? Like things I'm doing right/wrong...

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Some notes on the drawing itself: the walls in filed with black represent walls I'm adding—new walls. The red represents existing elements (power outlets in this case) where I'm thinking about drawing power from for the new lights, outlets and switches. The green rectangles represent the areas of ceiling drywall I'm thinking of removing in order to accommodate for drilling the floor joists in ceiling from floor above and passing the necessary cables. The joists from ceiling run vertical in the image.


  • Switches that control lights form two locations are called 3-way (it has 3 terminals) and diagrammed S3. The middle switch in a three switch configuration is called a 4-way (4 terminals), and is diagrammed S4. Also, there needs to be traveler wires running between each 3-way and 4-way switch. Your upper right circuit lacks that connection.
    – bib
    Feb 11, 2015 at 22:55

1 Answer 1


Assuming that the S's represent switches to control the lights, here are my thoughts...

  • Generally, you do not want your lighting on the same circuit as outlets in the same room. That way if you trip a breaker with a plugged in device, your lights don't go out. This is especially helpful when trying to do the wiring itself because if the outlets and lights are on separate circuits, then you can have the overhead lights on while you are wiring the outlets, and you can plug in lights while you are wiring the overhead lights.
    • If you don't have a nearby lighting circuit available, you will either have to add one to your breaker panel, or you will have to get approval from your electrical inspector or local code authority to use the existing outlet circuit.
  • The new best practice is that the power for lights enters the box with the switch, then it goes to the lights. (And in some places, this is code.) It's not clear from your diagram if that is what you intend to do.
  • From your diagram, it's not clear that you understand how 3-way and 4-way switched lighting circuits work. See http://en.wikipedia.org/wiki/Multiway_switching#More_than_two_locations or consult a professional.
  • For stairs, you must be able to turn on the ceiling lights from both the top and the bottom. I can't tell from your diagram if you plan on doing this, or if the existing lighting already does this. Since you're messing with the lighting in the area, the electrical inspector may insist on this, even if you aren't actually touching that lighting.
  • Thanks for the thoughts.. Some notes/follow up questions on them.. 1 - Where would I draw the power to the lights from then? Strangely enough this "basement" (it's more like a 'bottom floor' as it is a split-level home) doesn't have any ceiling lights... how would I draw power from if I don't have any dedicated "light" wiring to start with. 2 - Does that mean that I would have to connect each switch first, and then go off to lights? Or can I start at a switch (easiest one as far as reach/accessibility goes) and then finish in switches, or go to switch mid-way (again depending on accessibility)
    – ttothec
    Feb 11, 2015 at 22:48
  • 3 - How many switches for a group of lights can I have... for the hallway lights (the ones at the bottom of the stairs) I have already 3 downstairs, can I add/extend to a forth up the stairs?
    – ttothec
    Feb 11, 2015 at 22:48
  • See my edits above. I think I answered your 3 questions.
    – longneck
    Feb 11, 2015 at 22:53
  • edits make sense... I certainly underestimated this.. not a novice project for sure. I'll stick to the framing and drywall work! :) Thanks again for the help!
    – ttothec
    Feb 11, 2015 at 23:37
  • Just to clarify -- going "feed" - "switch" - "light" - "light" - "switch" is possible, and you can still get neutrals to all the boxes. However, you need an oodle of /4 NM to do it as the travelers are running the full length of the circuit :) Dec 13, 2015 at 21:35

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