Occupancy Sensor

Occupancy sensors are devices that detect the presence of people in a room and use that information to trigger automated responses, most commonly turning lights on when someone enters and off when the space is vacated. The technology relies on passive infrared detection, ultrasonic sound waves, microwave radar, or a combination of these methods to sense human movement and presence. Originally developed for commercial energy management in office buildings, occupancy sensors have become increasingly sophisticated and affordable for residential use, where they serve as fundamental building blocks of home automation that reduce energy waste and enhance convenience throughout the house. In residential interior design, occupancy sensors have evolved well beyond the utilitarian wall-mounted units familiar from commercial hallways. Modern smart home occupancy sensors can be discreetly integrated into light switches, ceiling fixtures, or standalone devices no larger than a small puck. Their role has expanded from simple light control to informing thermostats when rooms are empty, triggering welcome scenes when residents arrive home, adjusting whole-home audio playback to follow people from room to room, and providing security monitoring by detecting unexpected presence. The most design-conscious approach embeds occupancy sensing into devices that already exist in the room, such as smart light switches or smart thermostats with built-in sensors, eliminating the need for any additional visible hardware.