How to choose
between KNX, Wi-Fi and Zigbee?
The smart home industry is full of competing standards. Below we compare five of them on the criteria that matter five years after installation: reliability, vendor lock-in, cost, scalability, support.
protocols compared · 5 axes
Five protocols, twelve criteria.
Ratings go from zero (“cannot”) to five stars (“excellent”). This is not marketing — these are our observations after 12 years of projects.
| KNX | DALI | Zigbee | Matter | Wi-Fi | |
|---|---|---|---|---|---|
| Reliability (10+ years) | ★★★★★ | ★★★★★ | ★★★★ | ★★★ | ★★ |
| Vendor lock-in | None | None | Low | Low | High |
| Network type | Wired | Wired | Wireless mesh | Wireless | Wi-Fi |
| Works without internet? | Yes | Yes | Yes | Partially | No (usually) |
| Cloud account required? | No | No | No | Optional | Usually yes |
| Security | High | High | AES-128 | AES-128 | Variable |
| Compatible manufacturers | 500+ | 100+ | 300+ | Growing | Thousands |
| Device cost | €€€ | €€ | €€ | € | € |
| Labour cost | €€€ | €€ | € | € | € |
| Scales to 100+ points? | Yes | Yes | Yes | Limited | Limited |
| Suited to residential | ★★★★★ | ★★★★ | ★★★★ | ★★★ | ★★ |
| Suited to retrofit | ★★ | ★★ | ★★★★★ | ★★★★ | ★★★★ |
Which protocol for what.
For every situation the winner is different. This is how we decide at 2Smart House.
Villa under construction
Wired KNX, always. Plus DALI if you want professional lighting. The foundation for 20+ years.
Apartment under construction
Wired KNX. Low incremental cost while the finishes are open, major benefit to the apartment’s value.
Lived-in apartment
Zigbee or Matter over Thread. Retrofit without opening up the walls. Covers 80% of the usual scenes.
Rental / temporary
Matter over Wi-Fi. Portable devices you take with you. No changes to the apartment.
Restaurant / commercial space
Standalone DALI for lighting plus dedicated access control. Wireless only for extensions.
Residential development (B2B)
Wired KNX, without exception. Schematics are documented, systems are handed over, the developer has a clear ROI.
Tight budget, basic smart
A Matter / Zigbee package at half the price. Real limitations, but functional for lights and a thermostat.
Smart home + Apple HomeKit
Matter over Thread, native integration. Or KNX + a Matter gateway for the best of both.
For our clients: KNX during construction, Zigbee/Matter for retrofits.
That is the simple rule. The rest are details we discuss at the first visit. Wi-Fi smart home (Sonoff, Tuya, Yeelight) is not in our portfolio — we do not turn away clients who use them, but we do not install them ourselves.