Shelly vs C-Bus:
which one does your house actually need?
They are not competitors. One is a wired backbone that was built into your walls; the other is a small module that hides behind a light switch. Confusing them is how people waste money.
If you own a house built between 2003 and 2015 in Melbourne's eastern suburbs, there is a good chance it already has C-Bus. If you own anything else, it almost certainly does not — and that is where Shelly comes in.
This article is the comparison we give on site, minus the salesmanship.
The one-sentence version
C-Bus is a wired system: one backbone, hundreds of circuits, built to last twenty years. Shelly is a retrofit: it clips in behind an existing switch and makes that one thing smart, in ten minutes, with no new cable.
What C-Bus actually is
Clipsal C-Bus puts every light, fan and blind circuit back to a bank of modules in the switchboard. Thin low-voltage cable — the "bus" — links the wall panels together. Any panel can control any circuit, and one button can trigger a scene.
It is genuinely good engineering. A 2007 installation is still switching 47 circuits today in houses we service. The system is now sold by Schneider Electric as SpaceLogic C-Bus — same protocol, same bus, new part numbers. Old and new modules coexist on the same network, which is why an existing C-Bus house can be extended instead of replaced.
What Shelly actually is
Shelly is a family of small Wi-Fi relays made in Bulgaria. A Shelly Plus 1 is about the size of a matchbox: it sits inside the wall box, between the switch and the light, and adds app control, schedules and voice control.
The switch on the wall keeps working exactly as before. The app is an additional way to control it, not a replacement. There is no subscription and no cloud dependency for basic operation.
The comparison that matters
| C-Bus / SpaceLogic C-Bus | Shelly | |
|---|---|---|
| Wiring | Requires cabling to every circuit | Uses the wires already there |
| Best time to install | New build or renovation | Any time, walls finished or not |
| Scale | Hundreds of circuits, whole house | One point at a time |
| Reliability | 20+ years, industrial-grade | Good, but it is consumer hardware |
| Depends on Wi-Fi | No (local bus) | For app control, yes |
| Cost, per point | High up front, low over time | Quoted per point |
| Typical use | Whole-house lighting, blinds, scenes | One lamp, one blind, a garage door |
When C-Bus wins
If the wiring is already there, C-Bus wins by default — you would be mad to rip it out. It handles load properly, it does not care about your Wi-Fi, and the wall panels keep working when the internet is down.
If you are building or doing a major renovation, C-Bus (or its modern equivalent) still gives the best long-term result for whole-house lighting.
When Shelly wins
Shelly wins in every situation C-Bus cannot reach:
- The bedroom lamp that is not on a switched circuit
- The garage door motor that only has a wall button
- The towel rail nobody remembers to turn off
- The blind with no cable to the switchboard
- A rental where you cannot rewire anything
Can you run both? Yes — and most of our clients do
C-Bus and Shelly are separate systems that can be joined at the app level. C-Bus controls the circuits that are wired to it; Shelly handles everything else. On the phone, they appear in the same room, on the same screen, under the same scene button.
That is the arrangement we install most often in an existing C-Bus home: keep the backbone, fix what is broken, and use Shelly for the corners.
The practical answer
If you already have C-Bus: keep it, get it back on your phone, and add Shelly where the wiring stops.
If you do not have C-Bus: do not install it just to get app control. Use Shelly behind your existing switches — and consider a wired system only if you are renovating.
What it costs, roughly
For an existing C-Bus home, putting the system back on a phone is a one-off from $699 for up to 30 channels, plus $29 a month if you want someone watching it. Shelly is quoted per point after the free check.
A new C-Bus installation is a different order of money, and only makes sense during a build or renovation.
Three things people get wrong
- Buying Shelly for a whole house. Twenty modules in twenty wall boxes is not a system; it is twenty Wi-Fi devices to manage. Past about six points, a wired solution is cheaper and calmer.
- Being told C-Bus is obsolete. It is not. It is still manufactured as SpaceLogic C-Bus. What disappeared was the dealer, not the product.
- Mixing brands without a plan. C-Bus + Shelly + Hikvision + two other apps is not integration. Pick one place for everything to land.
Not sure which you have?
Send a photo of your switchboard. We will tell you what it is and what it can still do — free, across Greater Melbourne.