In the evolving landscape of smart buildings, knowing how many people are in a space at any given moment is more valuable than ever. People occupancy counting delivers this critical insight, providing real-time visibility into space usage and enabling data-driven decisions for energy efficiency, operations, and space management. Unlike people flow counting, which tracks movement across entry points, occupancy solutions focus on the presence and number of individuals within a space, offering continuous, reliable ground-truth data.
How to Count People in a Room?
People occupancy counting starts by monitoring how many individuals are physically present in a defined area, whether it is a meeting room, open-plan office, classroom, or waiting area. Unlike entry-based flow counters, occupancy sensors are installed centrally in the space, providing wide coverage and persistent monitoring. Terabee’s thermal-based occupancy sensors are designed for this purpose, offering real-time people counting that respects privacy while delivering reliable data for space utilization.
What Is People's Occupancy Counting?
People occupancy counting tracks the actual number of people in a space at any moment, rather than monitoring how they move. This makes it especially powerful for smart building applications that depend on accurate, live occupancy information. From meeting room management to HVAC control, occupancy data ensures that systems respond based on true space usage – no assumptions, no estimations. Importantly, occupancy counters don’t accumulate error over time. At any point in the day, the system reports the real number of occupants in a space (zero included) providing a trusted foundation for automation and reporting.
Flow vs. Occupancy: What’s the Difference?
While people flow counting focuses on movement and directional tracking (entries/exits), occupancy counting is all about the current state of a space. Both solutions can deliver Occupacy insights, since data aggregation from flow counters also can provide how many people are present at a given time. However, the key distinction lies in reliability over time: using flow counters to calculate occupancy requires logic and risks accumulating errors as people move throughout the day.
In contrast, occupancy sensors report exactly how many people are in a space at any moment, ground-truth data that resets itself in real time. However, Occupancy counters do not provide any dynamic information, including which passage is used to access the space.
In short, occupancy counting is particularly valuable for environments that demand high accuracy for decision-making, automation, or reporting, especially when the “zero moment” (= empty space) is very relevant.
What Type of Occupancy Counting Technologies Exist on the Market?
The market offers several types of people occupancy detection solutions:
- PIR Motion Sensors – Passive infrared sensors that detect movement but can’t count people or determine actual occupancy.
- Binary Occupancy Sensors – These provide a simple “occupied/unoccupied” status but lack granularity.
- Air Quality devices – These devices provide approximate people counting information based on CO2 and other air quality values but accuracy is subject to a lot of factors such as room size, sensor location, etc… They also do not update in real time, since co2 levels take time to build up but also to lower down once the room gets empty. Usually they are considered very inaccurate.
- RGB Cameras Overhead Counters – Offer people counting features and are usually decently accurate, but raise privacy concerns and require heavier processing.
- Thermal Overhead Sensors (like Terabee proposed product) – Deliver reliable counting across a large area with complete anonymity, using the body heat signature to detect and count individuals.
Occupancy Analysis Platforms are also part of the solutions, being mostly Software that aggregate data from sensors, visualize flow patterns, and provide actionable insights.
Why Thermal imaging is the Smartest Choice for Occupancy Counting
Thermal imaging technology offers key advantages when it comes to people occupancy detection. By capturing the unique thermal signature of the human body, these sensors can distinguish people from static heat sources or objects, ensuring accurate counts even in complex environments.
Unlike camera-based solutions, thermal sensors do not capture images or visual identifiers, making them inherently privacy-safe and compliant with even the strictest data protection regulations. Additionally, thermal-based sensors are less sensitive to lighting conditions and can operate reliably in low-light or dark environments.
Why is People Occupancy Counting Important for Smart Building Optimization?
Accurate people occupancy data is the cornerstone of several smart building functions:
- Room & Desk Booking Systems: Automatically release or reassign unoccupied meeting rooms or workspaces.
- Space Optimization: Identify underused zones and adapt layouts based on real usage trends.
- Energy Management: Dynamically adjust lighting, HVAC, and ventilation systems based on occupancy to reduce energy waste.
- Operations Optimization: Schedule cleaning, security, or cafeteria services based on actual usage instead of fixed schedules.
These applications lead to leaner operations, lower costs, and a better experience for building users.
Is the Occupancy Analysis Privacy Safe?
Privacy is a critical consideration in people occupancy counting. Reputable providers, like Terabee, prioritize privacy by offering only solutions that rely on non-RGB-image-based technologies like low resolution Thermal Imagers. These sensors capture thermal information rather than identifiable visual data, ensuring that meeting room participants, documents on table, screens, presentation and customers can be counted without compromising individual privacy or confidential information. Transparency in data handling practices is paramount.
What are the Pros and Cons of People Occupancy Counting?
Pros of People Occupancy Counting:
- Real-time visibility into room and space usage
- Ground-truth data with no error accumulation
- Privacy-compliant, if performed with low-resolution thermal sensing
- Wide-area coverage can be possible with a single device
- Enables smarter automation and space utilization
Cons of People Occupancy Counting:
- May require central ceiling installation for optimal coverage
- Initial investment in sensor infrastructure and integration
- Counting accuracy can vary with extreme ambient heat or poor mounting conditions (though minimized with proper setup)
- Not as dynamic as Flow Counting, it’s preferred for semi-static situations where people sit or stand and talk
Conclusion
People occupancy counting is a powerful tool for modern buildings, delivering the accuracy and privacy compliance that today’s operations demand. With Terabee’s thermal-based occupancy counting sensors, building managers gain the ability to make data-backed decisions in real time whether to save energy, improve comfort, or optimize usage. If you’re seeking a ground-truth occupancy solution that respects privacy without compromising performance, this technology is the key to unlocking smarter, more sustainable spaces.
The Author: Baptiste Potier is the Product Director at Terabee, leading the strategy and development of the product range. He holds an engineering degree from a French engineering school and a Master of Science in Embedded Systems and Robotics, providing a strong technical foundation. His background includes hands-on experience in application development, computer vision, and software engineering.
