Office Design

Install Motion Sensors For Lighting

What Is It?

Occupancy or motion sensors — sometimes called vacancy or personnel sensors — are one of the most common energy efficient lighting strategies. They detect the movement of room occupants, turning off lights in unoccupied areas and turning them back on when occupants return. The most effective areas for sensors are areas that are not frequently used, areas with irregular use patterns, or areas where occupancy may be erratic and where lights are often and inadvertently left on, such as meeting or conference rooms, individual offices, copier rooms, bathrooms, and storage areas.

Occupancy sensors are comprised of a motion detector, which uses ultrasonic, passive infrared or dual technology; an electronic control unit; a controllable switch (relay); and a power supply (Graybar). There are various locations where a sensor can be mounted — such as wall (where a regular switch might go), ceiling, or upper corner — and one should consider the type of space (small room, narrow hallway, etc.) before mounting. Occupancy sensors only provide optimal results if they are calibrated, wired, and placed correctly. Users should carefully commission their control system to fit the particular space and communicate clearly with installers about their particular spaces, then monitor energy savings and success of technology for a span of time after installation. It is also essential to evaluate need before choosing light and sensor types. This can be done beforehand, using data logging techniques, some of which are explored on page 26 of ENERGY STAR’s Chapter on Lighting from their Building Upgrades Manual. You can find details on how to calculate energy savings here and how to find the return on investment (ROI) here.

Suggested motion sensor types based on location

Location type

Sensor Type 1

Passive Infrared = PIR; Ultrasonic = US; Dual Technology = DT

Application Style 2

Potential Energy Cost Savings 3

Private offices


Wall Switch


Open Offices

No Data

Ceiling mount, high wide-view corner mount if very large


Restrooms (multi-stall)


Wall Switch, ceiling mount


Restrooms (single user), copy rooms, closets


Wall switch

No Data



Ceiling sensor, narrow view




Wall switch, ceiling sensor


Conference/meeting rooms


Wall switch, ceiling mount




High mount, narrow view


  1. From Hubbell: Energy Savings with Occupancy Sensors
  2. From Pacific Gas and Electric: Occupancy Controls for Lighting
  3. From US DOE: Energy Efficient Lighting


Motion sensors are inexpensive and effective devices that can quickly and easily be installed on a wall or ceiling. Most pay for themselves in two to three years without rebates. Where utility rebates are available, the payback can be less than one year. Savings will vary depending on the area size, type of lighting, and occupancy pattern. Potential savings from motion sensor controls vary greatly, but study on the energy savings potential of lighting controls in commercial buildings found that daylighting control strategies can save an average of 30% of energy used (ACEEE) can save between 13-90% of lighting energy costs (Graybar).


Though occupancy sensors are the most commonly used lighting control mechanism, they must be carefully evaluated before and during the beginning of use. Some sensor systems can return no or negative energy saving results due to failure to commission them properly or monitor the reality of time during which the lights are on. If sensors are not calibrated properly or the right type of sensors are not used, they can be falsely triggered or stay on too long, wasting energy, or can go off too early without sensing movement, sending occupants into darkness.

Regulatory Impacts and Requirements

ASHRAE 90.1 (2010) gives standards for minimum efficiency in nonresidential (including high-rise residential and hotels) and commercial buildings. It requires that new buildings use occupancy sensors in all rooms of a certain type (see pg. 16 of NEMA’s document).

See also: National Electrical Manufacturers Association’s Guidance on 2005 Energy Policy Act (as modified in 2015).

Financing Options, Incentives, and Rebates





  • Boston University retrofitted garages with efficient fluorescents and an occupancy control system.
  • The Rockport Company, a division of Reebok, installed occupancy controls and new T-5 fluorescent lights for annual savings of $136,098 and 1,512,206 kWh.