Wireless Occupancy Sensor — Guide for Commercial Buildings

Meet Butlr

Discover what spatial intelligence can do for you.

Thank you! Your submission has been received!

Oops! Something went wrong while submitting the form.

What is a wireless occupancy sensor?

A wireless occupancy sensor measures whether people are in a space and sends that signal to lighting controls, HVAC systems, or analytics platforms.

Automatic lighting control (occupancy/vacancy modes)
HVAC setback and demand-controlled ventilation
Space utilization and people-counting analytics
Compliance with energy codes and corporate sustainability goals

Wireless sensors avoid the cost and disruption of running low-voltage wires to every device, enabling faster retrofits and flexible placement.

How wireless occupancy sensors work

Sensors use different physical principles to detect people. The most common types are:

Passive Infrared (PIR): Detects motion by sensing changes in infrared light caused by warm bodies moving across a sensor’s field of view. PIR is low-cost and widely used for lighting control.
Ultrasonic: Emits inaudible sound waves and detects motion from Doppler shifts. Good for detecting small movements but can trigger falsely from fans or machinery.
Microwave: Emits microwave signals and measures reflections to sense motion. More sensitive and longer range than PIR but can penetrate thin walls and cause false positives.
Thermal (heat-based) sensing: Measures heat signatures and patterns to detect presence, direction, and with advanced processing people counts. Operates in darkness and through occlusions without capturing images.

Wireless communication layers commonly used include proprietary RF, Zigbee, Bluetooth Low Energy (BLE), and other mesh protocols. Choice of protocol affects range, battery life, and integration with building systems.

Sensor technology comparison: pros and cons

PIR

Pros: Affordable, low power, good for motion-triggered lighting.
Cons: Requires line-of-sight, less reliable for stationary occupants, sensitive to ambient temperature.

Ultrasonic

Pros: Detects small, stationary motions; useful where PIR misses fidgeting occupants.
Cons: Prone to false positives from airflow, machinery, or fixtures.

Microwave

Pros: High sensitivity and coverage.
Cons: Can detect through partitions and cause false triggers; regulatory and interference considerations.

Thermal (anonymous heat-based)

Pros: Detects presence in darkness and behind partial occlusions, resistant to false triggers from HVAC, supports people-counting and dwell analytics, inherently privacy-preserving because it does not capture visual images.
Cons: Typically higher initial cost than basic PIR; advanced analytics may require cloud or edge processing.

Choosing the right technology depends on the space type, expected occupant behavior, privacy requirements, and integration needs.

Benefits & ROI of wireless occupancy sensing

Wireless occupancy sensors deliver a mix of energy, operational, and workplace benefits:

Energy savings: Automated lighting and HVAC adjustments reduce energy use. Savings often exceed the cost of deployment in 1–3 years for many commercial settings.
Lower installation cost: No conduit or extensive low-voltage wiring reduces labor and downtime, especially in retrofits.
Flexible deployment: Sensors can be relocated as space usage changes, supporting agile workplaces.
Better analytics: Advanced sensors provide utilization metrics that inform space planning and desk hoteling strategies.
Compliance: Helps meet energy codes and corporate sustainability targets.

When evaluating ROI, include hardware, installation, commissioning, network management, and software subscription costs against energy savings and operational efficiencies.

Use cases by space type

Open-plan offices: Combine ceiling-mounted thermal sensors for accurate presence and desk-level PIR for localized lighting control.
Conference rooms: Use high-accuracy presence and people-counting to ensure lights and HVAC run only when rooms are occupied.
Restrooms and corridors: Simple PIR or thermal presence sensors can dramatically reduce wasted lighting hours.
Warehouses and factories: Use robust thermal or microwave sensors to detect people in large, irregular spaces and control high-bay lighting.
Healthcare and education: Privacy concerns favor anonymous thermal sensing over cameras while still providing utilization data.

Integration and installation best practices

Determine integration path: Confirm whether sensors will talk to lighting control panels, a building management system (BMS), a cloud platform, or multiple endpoints.
Choose wireless protocol with the right trade-offs: Mesh protocols (Zigbee, BLE mesh) simplify large deployments; proprietary RF may offer longer battery life or simpler pairing.
Plan sensor density: Account for detection zones, room geometry, mounting height, and typical occupant behavior. Dense placement is important in partitioned or cluttered spaces.
Placement tips:
- Mount ceiling sensors centered over zones when possible for even coverage.
- Avoid pointing sensors directly at windows, HVAC diffusers, or heat sources.
- Use overlapping coverage to reduce blind spots, especially for PIR.
Commissioning checklist:
- Validate detection coverage with real occupants.
- Tune sensitivity and timeout settings for each space type.
- Document device locations, firmware versions, and network keys.

Privacy & compliance considerations

Privacy is a major concern in workplaces, healthcare, and education. Compare sensor types against these criteria:

Does the sensor record or transmit images? Camera-based systems capture images; thermal sensors record heat signatures and do not produce identifiable imagery.
Is data anonymized at source? Edge processing that extracts presence counts and then discards raw signals reduces privacy risk.
Can access to raw data be restricted and audited? Role-based access and secure APIs are essential for compliance.

Privacy-first thermal sensing offers accurate occupancy and people-counting without visual imagery, making it suitable for sensitive environments.

Buying and deployment checklist

Define objectives: Energy savings, utilization analytics, or both?
Audit spaces: Note ceiling heights, partitions, and typical occupancy patterns.
Select sensor mix: Match sensor type to space function (e.g., thermal for conference rooms, PIR for corridors).
Confirm integration: Verify compatibility with lighting controls and BMS, and ask about API access for analytics.
Evaluate maintenance needs: Check expected battery life, over-the-air updates, and diagnostic tools.
Pilot before scale: Deploy in a few representative spaces, measure outcomes, and refine settings before a full rollout.

Why choose privacy-first thermal sensing (Butlr differentiation)

Privacy-first design: Sensors detect presence and movement using thermal patterns without capturing video, helping meet privacy and regulatory expectations.
Robust performance: Thermal sensing performs reliably in darkness and through partial occlusions, reducing missed detections common with PIR.
Scalable options: Both wired and wireless thermal sensors support retrofit and new construction projects across offices, healthcare facilities, and public buildings.
Actionable analytics: Beyond on/off events, thermal platforms can provide dwell, directionality, and people-counting analytics that power space optimization and operational workflows.

Next steps and CTA

If your goals include energy savings, better space utilization, and strong privacy protections, consider a pilot deployment that pairs thermal occupancy sensing with your lighting and HVAC controls.

Schedule a site assessment to map sensor placement and integration needs.
Request a demo of occupancy and utilization analytics tailored to your building type.
Get a quote that compares wireless retrofit costs versus hardwired alternatives.

A short pilot will validate savings and inform a phased rollout that minimizes disruption while maximizing ROI.

Wireless occupancy sensors are a practical, cost-effective way to make buildings smarter and more energy efficient. Choosing the right sensor technology—especially a privacy-first thermal option—can improve accuracy, support compliance, and deliver richer analytics for facilities and workplace teams.