Prepare outdoor lights before putting drywall up

I'm trying to prevent extra and unnecessary work for a future project, adding outdoor lights under the deck floor at my basement patio door.

The previous owners of the house were using a light switch for all the basement lights. It's already connected to the breaker panel. I'm not using that light switch anymore for inside the basement itself and I want to use it for outdoor lights.

The only thing I need to do, I think, is to prepare an electrical wire so it will be easier to add the outdoor lights in the future. Then I don't have to cut into my drywall (ceiling and/or wall) that I'm about to put up.

What would be the best approach to do this? See attached drawing (the weather is currently too bad to take a real picture from the outside). I have vinyl siding on the side of the house.

I think the best plan would be to run the wire to a junction box set in the exterior face of the wall below the porch floor. Then you can run conduit and place light mounting boxes at the time when you actually install lights outside.

Yup, what Glenn says would be a good approach.  If you do want to run a wire straight to the future light location, be sure to use the correct type of wire (or enclose it in conduit) per local codes.  Standard Romex isn't good enough to have exposed to the elements.

Also pay a bit of attention to how you seal up the new hole you're putting in the exteriorwall.  Caulk it from the inside and also on the outside so rain doesn't work its way in.

I started by writing that one could run the wire to a box at one of the desired light locations, making sure to put the exterior wire in conduit. However, by code last I knew you are supposed to use a junction box to make that switch. So from a practical as well as code-compliant standpoint, just go to a J-box on the wall.

I only notice one romex going to the switch, so unless you removed other wires exiting that switch box you need to confirm you have both a hot and neutral connected to that switch. If you have confirmed that is run directly to the panel you should be OK, but many times the panel feed is run to the first fixture and a switch leg is run to the switch, which would not have a neutral unless you changed the connections.

I echo the wall mounted junction box, and would suggest you consider a wall mounted fixture for simplicity.

Do I just run a regular indoor electrical wire through the exterior wall and place it in a junction box that I mount close/on the exterior wall?

And then run outdoor electrical wire from the junction box to my fixtures?

I'm thinking of getting a longer drill bit and just drill a hole (slightly sloped from top to bottom so no water can come in) through the exterior wall. Then run the wire and seal it back up with flexible silicone on both inside and outside.

I'm assuming they build the exterior wall as illustrated below, I need to confirm that soon when I check it from the outside.

@John, the switch is now only connected to the breaker panel. With hot, neutral and ground. I removed the wire that was going to the fixture, since that fixture is now connected to a different switch.

I suspect that if the wire is exposed at all between when it leaves the side of the house and when it enters the junction box, it should be the kind of romex that is suited for burying.

But that can be avoided if you place the j box OVER the hole where it leaves the house.  J boxes have knockouts on the back so you can run the wire directly into it.  You do need a clamp where the wire goes into the j box so it doesn't rub and wear through the wire insulation.

Also, when drilling through the wall it's quite possible to snag the fiberglass insulation on the drill bit and create a fiberglass cotton candy mess in the wall.  Then you can't get the drill bit out and you're screwed.  I'd just play that by ear and be careful but maybe the other folks on the call have some easy solutions.

HI,  first are you happy with the switch location,  meaning which door do you use the most - slider or solid exterior door. In either case I would move the box to make it easier to access.  

Where are you going to hang the lights and what kind.  Spots or flood lights? Mounted under the decking or on the exterior wall of the sliding glass  door?  If it's lights on the wall then special wiring isn't required.

Then do a complete rough in. You do not have to connect the switch to the outside wire just yet. When you are ready to put your lights in you have the fixtures in place.  If I'm gonna do it, I do it now and I do it right, I dislike having to do it over.  

Also ask your building inspector. He might be real picky. Mine was. He took a tape measure to the wire coming out the receptacle boxes in my new build. I had to cut the wire down to 4 inches because 5 or 6 was too long. Then he came back and charged me again.  

I stilled offered him a cold drink and wished him well.  
God bless your work.

Correction, the new buildwas my dads house.   Sometimes things merge late at night.

Arthur, thanks for your input and advice!

The switch is pretty much at the right place. I will fine tune the position once I start working on drilling and pulling the wire. It's right by where you open the sliding patio door, so that area is the perfect location for the switch.

As for lights, they will get mounted under the deck floor, attached to the wood. Not on the house itself.

It will probably be spots, I haven't made up my mind yet. I'm assuming I can decide on this later. The deck itself has a roof with a nice ceiling and there are pot lights installed.

For now I just want to bring an electrical wire into a junction box right on top of the vinyl siding. Then I can continue putting my drywall up.

If the deck is roofed, it probably isn't such a big deal, but for full safety and code compliance the exterior J-box should be weatherproof material. They make gray plastic boxes with various kinds of wire in/outlets, and you want one with a back opening and enough side conduit openings for wires to lights.

If the deck roof doesn’t have enclosed walls and the floor would allow water to pass through (rai, garden hose, pressure washing) the the under deck ceiling is considered a wet location by nec. You’ll need to use UF wire from the switch box out. Some inspectors would be fine with a small coil of wire hanging under there for future use if the switch isn’t connected but to be safe land the UF into a weatherproof box using a weatherproof UF connector. This box can be much further than you ever plan to have the first light and when the layout is finalized the extra wire cut off.
You will have a hard time finding wet rated can lights but I have details for those too when the time comes. Installed 12 under deck “recessed” lights on two projects last month, passed inspections and customers happy.

I went ahead and did the exact measurements. It turned out I could just drill through the deck floor framing and could leave the vinyl siding untouched. I bought a weatherproof junction box and applied quite a bit of silicon (just to be sure) on the inside wall, on the wood where the wire exits the wall and also where the wire exits the junction box.

I'll let the silicone dry a bit longer, then tuck the wire in and screw the lid on the junction box. The wire is not connected to the power. When I have decided on my lights I will cut the wire down to the appropriate length and hook it up to the light switch. For now I just put a blank wall plate on the wall.