Direct answer
The result depends on which functions are local, cloud-dependent, network-dependent, or backed up. Locally programmed lighting, keypads, climate schedules, and some security functions may continue during an internet outage, while remote access, streaming services, cloud notifications, weather data, and some voice assistants stop. Control4, for example, distinguishes local operation from cloud-enabled features available through Control4 Connect.
A power outage is different: controllers, network switches, access points, cameras, and motorized equipment require electricity. A correctly sized UPS can keep selected control and network equipment operating during a short outage, but it will not run the entire home indefinitely. Manual controls should remain available. Before installation, document expected behavior during loss of internet, local network, controller, cloud service, and utility power; those are different failure modes and should not be reduced to “works offline.”
Sources and technical references
Use the organizations responsible for a product, platform or standard to confirm current specifications and compatibility.
How this answer was prepared
Camelback Smart Homes publishes this FAQ library for homeowners, design professionals, builders and property teams comparing integrated technology. Answers begin with the practical conclusion, then explain the factors that can change it.
Limitations: This is general educational information, not a site-specific design, quote, code determination or compatibility guarantee. Final requirements depend on the property, construction, infrastructure, equipment versions and project goals.