Intercom - Door and Room Communication System Guide

An intercom is a wired or wireless communication device that lets people talk between rooms, entries, or gates without using the phone network.

What It Is

An intercom system connects stations placed in different parts of a building so occupants can speak to each other or identify visitors before unlocking a door or gate. Residential systems range from simple audio-only room units to video door intercoms tied into electric strikes and access control.

The system usually includes a master station, one or more sub-stations, low-voltage wiring or wireless links, and a power source. It matters because it adds convenience, visitor screening, and in some cases a controlled way to grant entry from inside the house.

Types

Common types include room-to-room audio intercoms, video door intercoms, gate intercoms, and smart app-connected systems. Some are fully hardwired, while others use Wi-Fi or a hybrid of low-voltage wiring and network equipment.

Where It Is Used

Intercoms are used at front doors, driveway gates, detached garages, large homes, multifamily entries, and older whole-house communication systems. They are most useful where someone wants to verify a visitor before opening an exterior door.

How to Identify One

Look for a wall station, handset, speaker grille, call button, or camera panel labeled for room or entry communication. At the exterior, the intercom is often integrated with a doorbell panel, keypad, or gate operator controls.

Replacement

Replacement is common when stations fail, audio becomes noisy, wiring degrades, or the owner wants to upgrade from audio-only to video and smartphone control. Simple station swaps are usually low-voltage work, but replacing an integrated door entry system may also involve locks, gate hardware, or network setup.