Last month my ISP went down for six hours. My neighbor’s smart home was completely dead – no lights, no thermostat, no locks. Mine kept running as if nothing happened. Here is how.
Rule 1: Local Processing
Home Assistant running locally on a mini PC is the foundation. All my automations, dashboards, and device control run on my local network. No cloud server needed. If my internet goes down, everything except voice assistants and remote access keeps working.
Rule 2: Local Protocols
Zigbee and Z-Wave devices communicate directly with my coordinator, not through the cloud. Compare that to WiFi smart plugs from Tuya – most of those require a cloud connection to function. I specifically avoid any device that needs internet for basic operation.
Rule 3: Backup Power
My Home Assistant server, network switch, router, and Zigbee coordinator are all on a UPS. That gives me about 4 hours of runtime during a power outage. Lights, locks, and sensors keep working. Cameras record to local storage.
Rule 4: Manual Overrides
Every smart switch in my house still has a physical button. Every smart lock has a keyhole. Automation is great until it is not, and you should always be able to control your home the old-fashioned way.