Overview
Workplace occupancy sensors measure presence and movement inside buildings to inform space planning, HVAC control, and safety systems. In this guide, "occupancy sensor" refers to any device or system that detects whether a space is occupied and/or counts the number of people in a defined area. "Thermal sensing" refers to non-imaging heat-based detection that senses body heat without capturing visual images. "Privacy-first" describes approaches that preserve personal identity by avoiding video capture and minimizing raw data collection.
Butlr is an AI technology company specializing in privacy-first people sensing and spatial intelligence for buildings, using a thermal, camera-free sensing platform. This guide outlines practical accuracy benchmarks for 2026, test methodologies, deployment considerations, and vendor-evaluation criteria focused on actionable, privacy-respecting implementations.
Why accuracy matters
Accurate occupancy sensing improves energy efficiency, occupant comfort, utilization analytics, and compliance with safety protocols. Errors have direct operational and financial consequences:
- Overcounting can lead to wasted HVAC energy and misleading utilization metrics.
- Undercounting can compromise safety (e.g., emergency roll calls) and result in under-provisioning of amenities.
- Poor temporal accuracy degrades responsiveness for real-time control (lighting, ventilation).
Key metrics must be clearly defined and measured to ensure reliable, repeatable results across environments.
Key metrics and 2026 benchmark targets
Detection metrics
- Presence detection accuracy (binary occupied/unoccupied): target ≥ 95% under normal conditions.
- False positive rate (detecting people when none present): target ≤ 5%.
- False negative rate (failing to detect present people): target ≤ 5%.
Counting metrics
- Person-count accuracy (absolute error): mean absolute error (MAE) ≤ 0.5 people for small rooms (≤ 6 people), MAE ≤ 1.5 people for medium rooms (7–20 people).
- Relative count error for crowded areas: ≤ 10% for densities up to 1.5 people/m², degrading gracefully beyond that threshold.
Spatial and temporal metrics
- Localization accuracy (centroid error): ≤ 0.5–1.0 meter for desk- and room-level positioning.
- Temporal latency (time-to-detect from event): ≤ 5 seconds for real-time control scenarios; ≤ 30 seconds acceptable for trend analytics.
- Sampling frequency: recommend ≥ 0.2 Hz (every 5 seconds) for control scenarios; lower rates ok for long-term analytics.
Reliability and robustness
- Operational uptime: ≥ 99.5% (accounting for maintenance windows).
- Performance stability over temperature variation: maintain benchmarks across typical indoor ranges (15–30°C).
- Degradation under occlusion/overlap: graceful reduction with documented limits (e.g., performance maintained for up to 2 overlapping bodies).
Accuracy targets should be validated with confidence intervals (e.g., 95% confidence) and reported with test conditions.