Security System Prewire for New Construction: Cost, Options

What does a security prewire include?

A prewire is cable only. It is pulled after framing and before insulation and drywall, and nothing is connected until a system is installed later. Installers describe the same core reason: running wire is easier and faster while the walls are open. MidTenn Alarms, a Tennessee installer, says prewiring during construction "is typically more cost-effective than retrofitting" and lets wires be hidden in walls, floors and ceilings. EPS, a Houston and Lafayette installer, sells a traditional prewire package that covers alarms, cameras, doorbells and automation.

What a typical prewire plan covers:

The last two rows are where we would spend first. Cameras and doorbells are the devices most likely to need power, and adding cable to an eave after the house is finished is the job most people end up paying for. PoE vs WiFi security cameras covers why wired cameras are worth planning for.

What does a prewire cost?

We could not find a published residential prewire price from the installers we checked as of October 2026. MidTenn Alarms and EPS both describe their prewire service without a price. Prewire is quoted per house, usually by the number of runs (often called drops) and the size of the home.

What drives the quote:

• Number of openings. Every contacted door and window is its own run, so a house with many ground-floor windows costs more to prewire than one with few.
• Camera and network runs. These use heavier cable and often run to the attic or eaves.
• Whether the builder or a security company does it. A builder may offer prewire as an upgrade option, or you can hire a security or low-voltage installer directly. Get the per-run price and exactly what is included in writing either way, so the two can be compared.

For the cost of installing the system itself once the house is finished, security system installation cost collects every fee that providers publish.

Is a prewire worth it if you will use wireless sensors?

Partly. Modern DIY systems are wireless by design, and wired vs wireless security systems lays out the trade-off: wireless sensors install in minutes but need battery changes, while wired sensors avoid batteries and radio interference but need cable in the walls.

A prewire keeps both doors open. If the runs exist, you can later connect them to a traditional panel monitored by any compatible central station, or to a smart board. Konnected, for example, sells a 12-zone board ($219, board only, as of October 2026) that connects existing wired sensors and a siren to a smart home system, and says the core system works without a required monthly fee, with professional monitoring as an optional extra. If you never use the sensor runs, the cost is a few spools of cable sitting in your walls.

Where a prewire matters least: a renter-style setup where you know you will use a closed DIY kit and a few wireless cameras. Where it matters most: a larger house, a home you plan to stay in, or anyone who wants hardwired cameras on the eaves.

Prewire is one item on the move-in list. The rest, from rekeying to resetting codes, is in the new home security checklist.

How do you plan the prewire with your builder?

Do it before the pre-drywall walkthrough, with a floor plan in hand.

1. Mark every exterior door and every ground-floor or deck-accessible window you want contacted.
2. Choose a panel location in a closet or utility room with an outlet and room for a network switch if you want wired cameras.
3. Mark keypad spots at the doors you actually use, not only the front door.
4. Mark camera positions from outside: corners of the eaves, over the garage, the driveway, the back door.
5. Ask for the front doorbell to be wired to a transformer rated for a video doorbell.
6. Label both ends of every cable and photograph each wall before drywall goes up.

If you want a monitored system once you move in, our questionnaire at /quote fetches quotes from professional monitoring providers, and some will want to know the house is prewired. Whether monitoring is worth paying for at all is covered in is professional monitoring worth it.