The occupancy sensor: What is it and what does it do?

Mar 22, 2022

Table of Contents

    What is an occupancy sensor?

    An occupancy sensor is a sensor device (or network of sensor-based devices) which continuously measures physical human presence (or absence of presence) within designated spaces, where the sensor device (or the network of sensors devices) is placed. Data received from occupancy sensors is then collated into analytics, which are helpful in providing insights around building space utilisation (peak, average, minimum) as well as to support integration between other systems within the building ecosystem.


    • A “Sensor” refers to a device which measures, monitors, and captures target measurements based on a sensor’s functional purpose, which then outputs specific findings as data (outcomes).
    • “Occupancy” in context of this topic, relates to people, and the presence (or absence) of people within an area.
    • This therefore gives you the term “occupancy sensors” as covered within this article.
    occupancy sensors

    How do occupancy sensors work?

    The technology

    • Passive Infrared (PIR): Measuring infrared (IR) light bouncing from objects within a field of view.
    • Ultrasonic: These sensor uses ultrasonic pulses outside the capabilities of human hearing, to detect objects and measure distances.
    • Time of flight (ToF): This technology uses an object travel time within a distance, to measure occupancy.
    • Image based: This technology uses camera type images as part of its measurement.
    • WiFi: Most people should be familiar with WiFi. WiFi signals can be used to provide feedback around the presence of devices (such as mobile devices) within range and distances.
    • Hybrid: Some occupancy sensors combine multiple technologies as listed above, to give you multi-purpose sensors and data.

    Connectivity and Power:

    • Power: Occupancy sensors are powered with Micro USB (wired), with battery or with PoE (Power over Ethernet) network cables. The most time-consuming sensors for installations and maintenance are the USB wired sensors, while the most efficient sensors for installations and maintenance being PoE and battery powered. PoE sensors are most efficient since supporting both long term power (no battery changes) and secure reliable connectivity.
    • Connectivity: Examples of connectivity for occupancy sensors are through PoE (Power over Ethernet), via WiFi, or through a central gateway or host (via the network of 4G) on the floor (via WiFi). 

    Maintenance and infrastructure:

    Sensors do not have incandescent or fluorescent characteristics, which means they blend in well as part of building infrastructure. Occupancy sensors are interchangeable which improves the ease of maintenance of sensors. Being interchangeable and programmable means that sensors can quickly be swapped out, should there be any issues with individual sensors. Sensors do not have a lot of accessories, which makes them easy to manage. Examples of sensor accessories are mounting accessories, extender accessories (ceiling brackets) and field of view accessories (which help to focus a sensor in into a narrow space). Accessories are always optional and only used where needed.

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    What are the use cases of sensor technology. Who benefits?

    Since occupancy sensors helps to streamline building portfolios and space design, as well as building systems, there is a large group of people who benefit from the technology.

    Building Managers / Corporate Real-Estate (CRE) / Group Real-Estate (GRE) teams

    Without accurate occupancy data and space utilisation data; Building managers, CRE and GRE teams are forced to work based on occupancy estimation, often being caught on the side of having to be reactive as opposed to being proactive. By having access to automated, always available, and always up to date occupancy data, accurate operational decisions can be made quickly.

    Space planners

    Having up to date and accurate occupancy data helps space planners to adapt to requirements proactively, to ensure that spaces are designed to promote collaboration and to increase productivity. Occupancy sensors for offices for example enables space planners to plan office moves, redesign spaces, restack departments and migrate people to more functional spaces, with a lot more ease, than without having data at hand.

    Employees in the workplace

    Buildings and workspaces should support departments and employees to perform their work, tasks, activities, projects, teams and should promote and enhance collaboration and productivity. The more information and data you have to help measure, monitor and understand employee and activity trends, the better you can create and prepare spaces which are relevant to the employee. One methodology which is being adopted increasingly today, is that of activity-based working. The effectiveness of activity-based working is greatly increased by knowing what spaces employees, clients and contractors need and use.

    Human Resources

    Occupancy data is all about people and their movement trends. With this technology and data, HR can better plan and adapt to staff requirements and maintain policies for Hybrid-work (work from home, work from office, remote working, etc).


    With the level of visibility that comes with occupancy sensors; Client facing and customer focused spaces like conference rooms, client suites, hotdesks, coffee areas, lounges, restaurants etc. can be streamlined to increase the customer experience and return on investment.

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    Health and Safety

    Occupancy sensors can be used to support OHS, with real-time and historic occupancy data, occupancy versus capacity information and social distancing information. This is used to support health and safety policy enforcement, cleaning and hygiene services, workspace planning etc.

    Data Analysts and MIS teams

    International manufacturing, electronics and design standards for sensors, ensure that there is always an API (Application Programming Interface) to ensure compatibility with industry recognised software and systems. This to ensure that the data from sensors can be used for many applications.

    By receiving automated and accurate occupancy data from an occupancy sensor platform API, data analysts and MIS teams can build, integrate, and automate analytics and reports, incorporating people-occupancy and space-utilisation trends into their applications by location, by building, by floor, by date and time (by day /week /month /season…). This helps add another dimension to information received by business, for support planning, decision making and business strategies.

    By receiving automated and accurate occupancy data from an occupancy sensor platform API, data analysts and MIS teams can build, integrate, and automate analytics and reports, incorporating people-occupancy and space-utilisation trends into their applications by location, by building, by floor, by date and time (by day /week /month /season…), this to add another dimension to information received by business, to support planning, decision making and business strategies.

    System Integration

    Being able to trigger systems based on occupancy and presence, will streamline, and often reduce costs. Some systems do not need to be online until people arrive to use them. Having these systems online, while not being used, can be a waste of energy, equipment lifespan and money. Some examples of applications of systems integrations are occupancy sensors for lights, air-conditioning, booking systems, meeting room audio-visual equipment etc.


    Occupancy sensors can support security team capabilities, applications, and enhance security surveillance. These sensors create data which is able to help monitor occupancy of areas, incorporate occupancy into evacuation and security procedures, and to understand where to focus security efforts.


    Occupancy sensors directly relates to real-estate and buildings, which is one of the top three highest costs of most organisations. Unproductive or wasted (under-utilised) real-estate space and technology systems, can result in major unnecessary costs. When unproductive (under-utilised) spaces are identified, business can launch initiatives to turn spaces into productive and used spaces, to increase return-on-investment. Additionally, informed decisions can be made to reduce real-estate portfolios, thereby reducing costs of real-estate leases, equipment, I.T, energy, furniture, parking, insurance, facilities etc.

    Automated space utilisation data and information

    Occupancy sensors support automation in the workplace. This removing guess work and estimation, enabling you to be more precise and accurate with regards to the utilisation and occupancy of buildings and areas, at-the-press-of-a-button. Occupancy sensors removes the need for manual people counting which is prone to human error and therefore susceptible to inaccurate space planning data. Once set-up, these sensors are automated to run 24/7. One example of automation is “lighting”, which can be automated with occupancy sensors for lights, to support green ratings.

    What questions can be answered, with implementing occupancy sensors:

    • How many desks or hotdesks do we need?
    • Do we have enough meeting rooms?
    • Do we have enough collaboration spaces?
    • How many people do we have in the office by floor at peak times?
    • Do we have underutilised spaces and where are they?
    • Do we need to renew our lease?
    • Do we need a new or another building?
    • What type of workspace and meeting space is the most popular for our people?

    hot desk booking software
    Hot desks and desk booking

    Types of occupancy sensors

    There are occupancy sensors for offices as well as other types of areas, for small and focused spaces (like desks) and for large open areas (like conference rooms). The following types of occupancy sensors are the most widely used.


    This type of sensor is mounted under the meeting room table or under a desk, where an occupant is expected to occupy a seat or desk. This sensor tends to be a passive infrared sensor. The types of spaces which suit this type of sensor are desks, hotdesks and meeting rooms, but not couches, lounges, pause areas, coffee areas, multi-functional spaces (with moveable furniture), restaurants or open collaboration spaces.

    Under-desk sensors are occupancy sensors for offices, desk workspaces, co-working spaces, meeting rooms and meeting spaces, conference rooms, call centers, training venues…

    Ceiling mount

    Being a ceiling mounted sensor, this type of sensor is non-intrusive. This sensor can measure very large areas, grouped spaces and desks and specific points-of-interests like individual desks. This type of sensor can perform occupancy sensing and people counting. The types of spaces which suits this type of sensor are almost any area, which includes desks, hotdesks, meeting rooms, conference rooms, couches, lounges, pause areas, coffee areas, multi-functional spaces (with moveable furniture), restaurants, open collaboration spaces etc.

    Ceiling mount sensors are therefore suitable for almost any indoor environment and building space.

    Wall / Corner mount

    Some sensors can be used on walls or with corner mounts to give you occupancy or vacancy information.

    Retail and public spaces

    There are also types of sensors which specialise on Retail (Smart Retail), Airports and Transportation (Trains). These sensors are typically ceiling mounts and can extend to deep analytics which can include anonymous people counting, occupancy space utilisation, customer flow heatmaps, gender detection, gaze (view) direction, mask detection, group detection, customer vs staff identification etc. 

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    Data acquired from occupancy sensors

    Occupancy Sensors provide real-time views and historic trend data and analytics of occupancy levels and space utilisation, to help with space planning, space design and provisioning of services, technology, and other facilities, according to the requirements within the building.

    workspace analytics

    • Peak occupancy: This data presents a sort of worst-case-scenario and snapshot of when the space was the busiest, showing you when the highest number of people, or highest occupancy levels of people were detected within the space. This information is helpful to determine whether the targeted area is too small, too large, or right sized, based on the maximum number of people that used the space during the identified peak times.
    • Minimum occupancy: This data presents a sort of worst-case-scenario, and snapshot of when the space was the least utilised or under-utilised. With this data focus, sensors are used as vacancy sensors. This showing you when the lowest number of people, or lowest occupancy levels of people were detected within the space. This information is helpful to determine whether the targeted area is needed or not needed. If a space was identified as not used or poorly utilised (through means of vacancy sensors), the argument could be made that a) the space is not needed, or b) that the space should be redesigned or repurposed to improve its relevance and utilisation.
    • Average occupancy: Averaging occupancy data between peak and minimum space utilisation, provides a baseline and trend line, to support baseline planning.

    Integrations, IoT and Automation

    The types of occupancy sensors in the world are growing as they become more important to businesses. Besides providing visibility on space utilisation and trends, the new growing value for sensors are the fact that they support integration, Internet of Things initiatives, while enhancing automation. International Manufacturing standard of sensors place high importance on the compatibility of sensors, to support integrations, IoT and automation. Due to sensors being designed without incandescent or fluorescent characteristics, the potential application of sensors is wide in support of IoT and automation objectives.

    The future will be about increasing integration, data, IoT and automation, which will keep increasing strategic focus on occupancy Sensors.

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    Examples of integrations with occupancy sensors

    Desk Booking systems and applications:

    By integrating desk booking systems with sensors, you can enhance the desk user’s experience and convenience of using desks, by ensuring that desks which are showing as “available” are available, and not in use. Without this integration, a desk might show as “available” (not booked) while being used. The popular types of sensors with this type of use case are passive infrared and ceiling mount image based.

    Room booking systems and applications:

    By integrating room booking systems with sensors, you can optimise the meeting experience and convenience of using meeting spaces, by ensuring that meeting spaces showing as “available” are available, and not in use.

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    Check-in and early release:

    After integrating sensors with desk booking and room booking systems, bookings can automatically be ended if nobody arrives at the venue as booked, thereby making the space available for other people, who are looking for an available desk or meeting space. For the same reason, desk bookings and room bookings can automatically be released early, if an integrated sensor detects no presence, before the end of a booking. This can be configured to occur after a specific time frame where there is no presence detected.

    HVAC (Heating, Ventilation, and Air Conditioning)

    Environmental sensors are extremely popular for managing employee productivity and care. When integrated with sensors, HVAC systems can automatically change the state of systems based on occupancy. This will help to drastically optimise energy efficiency, power consumption, while reducing maintenance required and enhancing comfort levels.

    Vacancy Sensors:

    After being integrated, sensors used as vacancy sensors, can be used to switch off all unnecessary systems in the areas which are not utilised.

    Sensors for lights:

    Occupancy sensors for lights are used to trigger lights automatically, based on the presence or absence of people. This will help to enhance energy efficiency, power consumption, equipment lifespan, and reduce maintenance required.

    What about privacy when using sensor and occupancy technology?

    Since “Privacy” has been a global topic, international manufacturing, electronics, and design standards of sensors places a very high focus on the importance of privacy. Occupancy sensor data is anonymous in nature, only measuring occupancy and space utilisation, thereby complying with international security and privacy laws.

    Due to the emphasis of privacy, data displayed on software applications are anonymous, while only focusing on occupancy trends. Sensor manufacturers are happy to provide more information with their compliance, adoption and enforcement of security and privacy standards.

    Providing advanced facility management sensing solutions 
    Ceiling sensors in-use case

    Occupancy sensor relevance today

    Since the global pandemic, the design and purpose of buildings have changed dramatically, especially since the increase of hybrid-work and remote working trends. Impacts from the global pandemic have started to ease globally, but some say that the-way-of-work will never be the same again. Not only has the-way and where we work changed, but we have learned that we should be ready for dynamic lockdown-levels and social-distancing regulations, should there be another pandemic or unexpected external influence like Covid-19.

    Read more about our sensor technology being used in Deloitte’s new African headquarters.

    smart building in South Africa

    What does the future look like with occupancy sensors?

    The future of smart buildings, smart offices, smart retail, and smart workspaces will become more dependent on integration, IoT, data, automation, artificial intelligence etc., which means that technology like occupancy sensors are here to stay, with the expectation of increased expansion and integration into society. 

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