When designing a luxury smart home, few components are as deceptively important as motion and presence sensors. They quietly influence how lights behave, how climate systems respond, and how “intelligent” a home actually feels day to day.
At Highlands Smart Homes, this is a topic that comes up regularly with clients, particularly those familiar with premium automation platforms. On the surface, motion sensing feels like a solved problem. But once you dig deeper, especially into presence detection, the gap between traditional systems and newer technologies becomes very clear.
So why do most luxury smart-home platforms still rely on PIR sensors when newer technologies like mmWave radar appear vastly superior?
Let’s unpack it.
The Traditional Approach: PIR Motion Sensors
Passive Infrared (PIR) sensors are what most people picture when they think of motion detection. They’ve been around for decades and are used across residential, commercial, and security applications.
In smart homes, PIR sensors excel at one thing:
Detecting movement when someone enters a space.
They are reliable, predictable, and easy to install. For basic automations—like turning lights on when you walk into a room—they work extremely well.
However, PIR sensors have a well-known limitation:
They rely on detecting changes in infrared heat, not actual presence.
That’s why:
- Sit still for too long and the lights turn off
- Lie on a couch under a blanket and the room thinks you’re empty
- Read, work, or watch TV quietly and automations stop responding
PIR is good at detecting motion, but poor at understanding occupancy.
The New Contender: mmWave Presence Detection
mmWave sensors take a very different approach. Instead of relying on infrared heat, they use radar technology to detect movement at an incredibly fine level, down to chest movement from breathing.
This unlocks capabilities that PIR simply cannot offer:
- True presence detection (you’re “there” even when sitting still)
- Detection through soft obstructions (furniture, blankets)
- The ability to be hidden behind walls or ceilings
- Multi-zone detection within a single room
- Measurement of “movement energy” to distinguish still vs active occupants
In practical terms, this means:
- Lights stay on while you relax
- Climate systems respond to real occupancy, not guesses
- Automations feel natural instead of frustrating
On paper, mmWave looks like the obvious choice, especially for high-end homes.
So why isn’t it widely used in luxury automation platforms?
Why Luxury Smart-Home Platforms Still Rely on PIR
When you look at ecosystems like Crestron, KNX, Control4, Clipsal C‑Bus, and Savant, a pattern emerges.
The choice to stick with PIR isn’t about ignorance, it’s about risk management.
1. PIR Works (and Expectations Are Set)
PIR sensors are predictable. Integrators understand them, clients understand them, and their limitations are well-accepted.
In a luxury home, predictability often beats innovation.
2. R&D Risk and Product Guarantees
Premium automation brands have to stand behind their hardware for years, sometimes decades.
mmWave sensors:
- Require more processing
- Depend heavily on firmware quality
- Can behave differently in different spaces
The R&D investment required to make mmWave “bulletproof” at scale is significant, and the failure cost is high.
3. Simplicity of Installation
PIR sensors are effectively set and forget:
- Mount them correctly
- Walk-test
- Done
mmWave sensors, by contrast, require:
- Careful orientation
- Thoughtful placement
- Zone configuration
- Sensitivity tuning
In a $200k+ automation project, simplicity matters.
The Other Side of the Coin: mmWave’s Real Limitations
While mmWave offers impressive capabilities, it’s not without drawbacks, especially in luxury environments.
- Less stable than PIR when poorly configured
- More prone to false positives
- Requires calibration and adjustment
- Behaviour can be harder to explain to clients
Luxury clients expect systems to “just work”.
They don’t want recalibration visits or explanations about radar reflections.
At this level, even small inconsistencies can undermine trust.
The Irony: Prosumer Platforms Are Leading the Way
Interestingly, platforms like Home Assistant are often ahead of the curve here.
Why?
Because they embrace:
- Iteration
- Sensor fusion
- Rapid innovation
- Continuous improvement
In these systems, combining PIR, mmWave, door sensors, time-based logic, and context is not only possible, it’s encouraged.
The result?
Presence detection that feels genuinely intelligent.
The Future: Sensor Fusion, Not Replacement
This doesn’t need to be a PIR or mmWave debate.
The real future lies in sensor fusion:
- PIR for certainty (someone definitely moved)
- mmWave for confidence (someone is still there)
- Logic that blends both intelligently
This approach already exists in early products and custom implementations, and they’re proving extremely effective. One such example, as pictured with its cover off, is the everything presnece pro, here you can see two mmWave antena accompanied by a PIR sensor.
Luxury automation will get there too. It just moves more cautiously, and for good reason.
Final Thought
Would you trade absolute reliability for better presence awareness?
Or do you expect both in a premium smart home?
At Highlands Smart Homes, we believe the best systems balance innovation with reliability, choosing the right technology for the right environment, not just the most impressive one on paper.
If you’re building or upgrading a high-end smart home and want presence detection that actually feels smart, we’re always happy to talk.