Let KNX keep doing what it already does well
KNX is a wired control system where switches, sensors and actuators share one cable, called the bus. A good KNX installation already runs lighting, blinds, climate and more. Home Assistant can add dashboards, other brands and smarter automations on top, without moving every essential function onto the Home Assistant server.
Keeping that line clear means your wall switches and core KNX logic carry on while Home Assistant is being updated or serviced.
Start with the ETS project and group addresses
The starting point is the current ETS project (the file your KNX programmer used to set up the system), the keyring if Secure KNX is used, the group addresses that link switches to devices, and the device documentation. Without them, the job starts as detective work rather than a straightforward integration.
Home Assistant connects through a local KNX/IP interface or router. It sees bus messages as they happen, controls supported device types and can send selected Home Assistant states back to KNX.
Bring only the useful KNX functions into Home Assistant
Share the functions Home Assistant actually needs rather than importing the whole bus. Light states, temperatures, blinds, selected scenes and occupancy are often useful. Diagnostic or low-level addresses can stay in the KNX project.
Names and status addresses matter. Without a proper status address, a control can look great on screen but not reliably show what the lights or blinds are really doing.
Secure the KNX/IP connection and keep its details with the project
Note whether the connection uses KNX/IP tunnelling or routing, how it reaches your network and any KNX Secure keys. Keep the ETS and keyring files in your own hands, stored safely.
We test by comparing the wall switch, the messages on the bus and what Home Assistant shows. At handover, we tell you which automations run on KNX and which rely on Home Assistant.
Where to read more
Quick answers to common questions.
Can Home Assistant replace KNX?+
It can control and automate KNX through an IP interface, but a good design usually keeps essential control on KNX and uses Home Assistant to bring everything together.
What is needed to connect KNX to Home Assistant?+
A local KNX/IP interface or router, plus your group addresses and project files. Secure installations also need the right keys.
Does KNX work locally with Home Assistant?+
Yes. The official integration talks to KNX locally over KNX/IP and sees bus messages as they happen.
Can Home Assistant send states back to KNX?+
Yes, when set up deliberately. The integration can share selected states and send or receive supported KNX group messages.