Planning a KNX installation
This guide is for new builds or major renovations where you're considering a KNX installation. It walks through the components a typical KNX installation needs, where they go physically, and where the Atios KNX Bridge fits in — so you can plan a tidy electrical cabinet and avoid buying boxes you don't need.
If you don't yet know whether KNX is the right choice, start with What is KNX?.
What a typical KNX installation includes
In the electrical cabinet (DIN rail)
- KNX power supply — feeds the KNX bus with 30 V DC. One per line.
- KNX IP interface — exposes the KNX bus over the network, so ETS can program it.
- KNX actuators — switching, dimming, and blind actuators that drive the loads. One actuator output per controllable circuit.
- KNX-DALI gateway — only needed if you're using DALI luminaires (most modern LED architectural lighting is DALI).
- App server / Matter Bridge — only needed if you want app and voice control. Not strictly required for KNX itself.
In the heating panel
- KNX heating actuator — drives the valves for floor heating or radiators. Best installed in or near the heating panel because the valves usually live there too — keeps the wiring runs short.
Throughout the rooms
- KNX wall switches and keypads — connected to the KNX bus (green cable).
- Motion / presence detectors — for hallways, utility rooms, WCs, and any room where you'd rather not flick a switch.
- Temperature, humidity, CO₂ sensors, weather stations — many KNX keypads include a temperature sensor, so you may not need a separate room thermostat.
- Door and window contacts — for security and HVAC interlocks.
The wiring
Three cable types typically run in a KNX installation:
- KNX bus (green, two-wire, low-voltage) — connects all KNX sensors and actuators to the bus.
- DALI bus (typically yellow, two-wire, low-voltage) — only present if you have DALI luminaires. Runs from the KNX-DALI gateway in the cabinet to each DALI fixture.
- 230 V mains (black) — runs from the actuators in the cabinet to switchable outlets, motorised blinds, lights without DALI, and so on.
Where the Atios KNX Bridge fits in
The Atios KNX Bridge combines three roles in a single DIN-rail device:
- KNX IP interface — for ETS programming and network access
- KNX-DALI gateway — built-in 64-address DALI master with DT8 support
- Matter Bridge — exposes the entire installation to Apple Home, Google Home, Alexa, and SmartThings
This means three boxes you'd otherwise plan for collapse into one. In a typical cabinet this saves DIN-rail space, simplifies the cabling, and gives you a single device to maintain and update.
Recommended planning order
- Decide which lights are DALI vs conventional. DALI luminaires give you smooth dimming and tunable white; conventional lights are switched or mains-dimmed via a switching/dimming actuator. The split determines whether you need a KNX-DALI gateway at all.
- Plan keypad and sensor placement. Standardise so every room has the same operating logic — for example, two lights and one blind rocker on every keypad. Use motion detectors in transitional spaces (corridors, utility rooms, WCs).
- Size your actuators. Count circuits per room: ceiling lights, switched outlets, motorised blinds, heating valves. Add 10-20% headroom for future changes.
- Place the KNX Bridge in the main cabinet. It needs a network connection (Ethernet with PoE preferred, or Wi-Fi) and access to the KNX bus.
- Specify a Matter hub for the homeowner. One of: Apple HomePod, Google Nest Hub, Amazon Echo, or SmartThings Station. See Which Matter hub do I need?.
Future-proofing
- Reserve spare DIN-rail space in the main cabinet — adding actuators later is trivial; finding space for them is not.
- Pull spare KNX cable runs to rooms where the wall layout might change (kitchens, master bedrooms).
- Specify named conduits for future DALI extensions if not all luminaires are DALI yet.
- Plan the network switch to have at least one free port for the KNX Bridge plus headroom for a Matter hub or two.