Hello everyone,
I’m Anthony, I think I’m almost 36 years old 
.
I’m passionate about gardening/computers.
I have been aware of Gladys for quite some time, without ever taking the plunge, I admit that if we could associate a Zigbee gateway without going through Smart life, I would take the plunge since it’s part of it, I’m starting my installation (Zigbee door sensor, Zigbee switch + motion detector).
Have a nice day.
Hi Anthony 
and welcome
Have you looked into Zigbee2mqtt? This allows you to avoid proprietary gateways
Oh yes I looked with the Sonoff USB dongle, but is the range long?
Since I have a stone house, I can tell you it’s quite thick .
Well in theory, but if I have more than 20 Zigbee devices, I’ll have to buy a new dongle.
Hello @Crash and welcome to the forum!
Don’t hesitate to create topics if you ever have any questions
This is considered based on what you want to install. Most Zigbee mains-powered devices (plugs, bulbs, switches, sirens, etc.) also act as relays. As a result, it creates a fairly effective mesh network!
Salut @Crash
I discovered that there are USB Zigbee repeaters to relay the network.
In addition to devices that also act as routers (basically anything that’s plugged into power), which could surely help you in your case.
Not to mention that, depending on the adapters, you can go well beyond 20 — more like 100+ devices.