Home Security Wiring

Several years back I started planning for the home security system. Most home security these days has gone wireless, but I found myself leaning old school. The wireless sensors generally cost around $30 apiece, have batteries to replace, and are typically bulky and can lose their connection, leading to lack of coverage or false positives. Conversely, the wired sensors are cheap. That same $30 gets you a bag of ten window and door sensors. Plus, they’re tiny, able to be concealed within the jamb so they are invisible. There’s no batteries to replace, I can literally put a sensor on every single door and window and a motion sensor in every room, and I can integrate it with smart home functionality. With the house gutted, running the wires is still an undertaking, but it’s not terribly difficult.

My goal with the system is to tie these sensors into triggers and actions. If it starts raining or the temperature suddenly drops and I’ve left a window open, I get a notification on my phone. If it’s night time and someone walks into a hallway or stairwell, the lights can come up just a bit, but during the day they can turn all the way on or not come on at all, whichever makes more sense for a given space. As an actual security system, we can either have it remotely monitored by an inexpensive service, or have it send us a notification if we’re away and a door or window opens or a motion sensor is triggered.

So as I said, I started planning this years ago. I did some research, picked out a system, wound up buying all the components, and they sat in a box collecting dust (I just checked and it was 2014!). I decided to wait until after spray foam to run the wires, since they’re fairly low profile. In hindsight, that was probably a mistake, but I wanted to be able to access it later if I really needed to even if it meant cutting drywall. It’s just 18 gauge 2-wire thermostat wire, so I picked up a 500 foot spool and started drilling into all my windows and jambs. Fishing the wires through the 3/8″ holes is tricky, and figuring out the best way to get the wiring into the ceiling while avoiding studs as much as possible, since that’s where drywall screws are likely to go is its own process, but it really isn’t too bad.

I decided to put the panel in the laundry room closet. It’s relatively central to shorten wire lengths with easy access to the area behind the attic knee wall above where I can run wires from one end of the house to the other. Initially I’d planned to only have motion sensors in the common spaces, but I wound up getting some PIR motion sensors for the bedrooms as well so we could tie smart triggers based on occupancy status. About the time I finished the attic and second floor, I bought a second 500′ spool of wire. The first floor was fairly straightforward, since by this point I’d gotten familiar with the process.

I thought the basement was the last step in the process, with the added challenge of getting the wires through two floors worth. I kept getting pulled away from this to work on other projects, but I got the back window and door wires run before I had to pick up a third 500′ spool. I really underestimated how much wire this would take, plus the spools aren’t particularly cheap. Parts of the beam look positively festooned where I set up raceways for converging sensor wires.

After I was done with the basement and ready to shift gears, I realized I was missing a few things. First, I had picked up a water level sensor for the mechanical room to alert me to leaks. Ok, just a forgotten sensor, run another line, all set. Then I realized I didn’t have power to the panel. The system uses a transformer, which I didn’t want to plug into one of the two outlets in the laundry closet, since they’re obviously for the washer and dryer. So instead I ran another line clear down to the mechanical room for that. Finally, I realized I needed to run the ethernet cable for the smart home integration, since I don’t have easy access to one of my drops, so I ran that through the wall to where I can connect it to a switch.

Next steps on this project can wait. I have all the wiring done and that’s what I need to have finished for drywall. I’ll have to install the PIR sensors after drywall, the sensors in the basement, all of the panel components, connect all the wiring, program the thing (since I didn’t label all my lines this will involve figuring out what everything is), and finally add the smart integration, which will be a whole other bit of programming.