The protocol is stamped into the motor at the factory. It cannot be changed, upgraded or flashed later. So this is one of the few decisions in a shade project that is genuinely permanent, and it is worth ten minutes before the order goes in rather than a year of workarounds after.
The published figures, side by side
| RTS | Zigbee 3.0 | |
|---|---|---|
| Frequency | 433.420 MHz | 2.450 GHz |
| Range, open field | 656.2 ft | 262.5 ft |
| Communication | One-way command | Two-way, with status back |
| Network shape | Point to point | Mesh — devices relay for each other |
| Encoding | Rolling code, 16 million combinations | Zigbee 3.0 security |
| Memory, typical motor | 12 transmitters | Managed by the hub |
| Hub required? | No — remotes work alone | Yes — TaHoma pro for setup and control |
Sources: Somfy's product records for 1001809 (RTS) and 1241755 (Zigbee).
RTS reaches two and a half times further, and it rarely matters
656 ft against 262 ft is a real difference, and it is a straight consequence of physics: 433 MHz penetrates walls and floors better than 2.45 GHz, and always will.
But open-field range is a lab number. In a house, RTS is a single hop from the remote to the motor, and everything in between eats into it: plaster and lath, foil-backed insulation, brick, a steel stud wall, a metal headbox. When an RTS shade at the far end of a house stops responding reliably, the fix is a repeater or a relocated transmitter, because there is nothing else in the system to help.
Zigbee starts with less reach per hop and then refuses to rely on one hop. Every mains-powered Zigbee device in the network relays for the others, so a house with eight Zigbee shades has eight relay points, and coverage grows as you add devices rather than shrinking. In a large or awkwardly built property, the mesh usually wins on delivered reliability despite losing badly on the spec sheet.
The caveat: battery Zigbee motors sleep to save power and generally do not relay. A house of battery-only Zigbee shades has a thin mesh, and the 262 ft figure starts to matter again.
Feedback is the real dividing line
RTS sends a command and stops. It does not ask whether the shade moved. If the motor was out of range, mid-cycle, jammed on a bent hem bar, or simply unplugged, the remote does not know, the hub does not know, and the app still shows the shade as closed.
Zigbee acknowledges. The motor reports back, so the hub holds the actual position rather than the last intention. In practice that unlocks three things RTS cannot do well:
- Accurate app state. A dashboard that shows where shades really are, not where they were last told to go.
- Conditional automation. Rules that read position — close the west shades only if they are open, lower to 40 percent, report anything that failed to move.
- Fault visibility. On a commercial install with sixty shades, a silent failure is one you find months later. Two-way turns it into a line in a log.
If someone is going to open an app and look at a screen, that screen should be telling the truth. That is the argument for Zigbee in one sentence.
Where RTS is still the right answer
No hub, no network, no account. An RTS shade and an RTS remote work out of the box with nothing else. No Wi-Fi, no gateway, no app, no cloud service that could change its terms. For a vacation home, a rental, or an owner who simply wants a button on the wall, that simplicity is a feature and not a compromise.
An existing RTS property. If a building already runs RTS, adding a Zigbee motor creates two parallel systems. Matching what is there is nearly always cheaper and better than running both.
Exterior and long-range. Awnings, rolling shutters and screens across a courtyard are exactly where 433 MHz earns its reach, and exterior motors are overwhelmingly RTS anyway.
Battery shades in a small property. With no mains devices to build a mesh, Zigbee's structural advantage largely disappears, and RTS's range advantage does not.
You can run both
This is the part people miss. The TaHoma Switch (1871037) speaks RTS and Zigbee at the same time, so a property can carry legacy RTS shades and new Zigbee shades in one app, one set of scenes, one schedule.
What it cannot do is grant RTS motors two-way feedback. Those shades still report as whatever they were last told. The hub unifies control, not capability — and that distinction is worth being explicit about with a client before they see the app.
Our TaHoma Switch guide covers capacity and setup, and the four-way control systems comparison adds SDN and wired for commercial work.
Choosing, in order
- Does the property already run one of them? Match it. Stop here.
- Is any shade exterior? Those are RTS. Decide the interior shades separately.
- Will anyone rely on an app or on automation that reads position? Zigbee.
- Is there a hub, and will there keep being one? If not, RTS.
- Are the interior shades mains-powered? That builds a strong mesh and makes Zigbee the safer bet in a large property.
Common questions
Can an RTS motor be converted to Zigbee?
No. The receiver is built into the motor at manufacture. Converting means replacing the motor.
Which has better range, RTS or Zigbee?
Per hop, RTS: Somfy publishes 656.2 ft open field against 262.5 ft for Zigbee. Across a whole property, Zigbee's mesh often delivers better real-world coverage because mains-powered devices relay for each other.
Do I need a hub for RTS?
No. RTS remotes and wall switches control motors directly. A TaHoma hub adds app control, scheduling and voice, but nothing about basic operation requires it.
Does Zigbee tell me where the shade actually is?
Yes. Zigbee is a two-way protocol, so the motor reports status back to the hub. RTS is one-way and does not.
Can RTS and Zigbee shades live in the same house?
Yes. The TaHoma Switch controls both. RTS shades still will not report position.
Does Zigbee interfere with Wi-Fi?
Both use the 2.4 GHz band, so a congested Wi-Fi environment can affect Zigbee performance. It is usually solved by choosing a Zigbee channel away from the busiest Wi-Fi channels. RTS at 433 MHz avoids the band entirely.
Range and frequency figures above are taken from Somfy's published records for the specific part numbers, linked in the sources line. Browse Somfy RTS, Somfy Zigbee and Smart Hubs.
