Rako Controls, founded in the UK in 1994, makes wireless dimming systems that have become a fixture of the UK residential smart lighting market. The WK-series wireless dimmers (wall-plate retrofit units) allow ceiling rose-level dimming installation without any new cable runs — the dimmer sits behind the existing wall plate and communicates over 433 MHz RF. For UK retrofit projects where the electrical infrastructure does not support a full DALI-2 or KNX TP cable run (Victorian terrace houses, Georgian townhouses, converted flats where running new conduit is structurally or aesthetically prohibited), Rako fills a practical gap that KNX cannot. The integration challenge: making Rako and KNX share scenes and respond to each other.

When to choose Rako vs DALI-2 in a hybrid project

A structured approach to zone allocation prevents the common mistake of forcing wireless into every room (losing reliability) or forcing cabled DALI-2 into rooms where the installation disruption is disproportionate. **Use DALI-2 for:** Open-plan living areas where new cable runs are accessible during renovation (ceiling before boarding, first fix). Commercial-grade spaces requiring EN 50172 emergency lighting testing. Corridors and common areas where a uniform, wall-flush look is non-negotiable (Rako wall plates are slightly thicker than standard UK plates). Rooms with high luminaire count (>6 circuits) where Rako's per-ceiling-rose cost accumulates. Office zones where addressable dimming of individual circuits is needed (Rako addresses by room/scene, not individual circuit). **Use Rako for:** Bedrooms where no new ceiling cable is planned — a Rako WK-series dimmer replaces the existing wall dimmer without touching the ceiling rose, adding a second cable core, or disturbing plasterwork. Studies and snugs with one or two circuits. Rooms in listed or heritage buildings where any ceiling work is consented-restricted. Rooms where the renovation budget does not allow for replastering after cable run. Master bathroom lighting where the existing cable is in conduit and extending it would require permit applications (Part P notifiable work in England — see below). The hybrid boundary should be agreed with the client before design finalisation — it directly affects both the cable plan and the control logic.

RA-BRIDGE wiring and ETS6 programming

The Rako RA-BRIDGE (previously called the RK-BRIDGE) is the hardware interface between the Rako wireless system and external control networks. It connects via Ethernet (RJ45) and exposes a TCP/IP API (Rako API v3, documented on Rako's developer portal). The Bridge manages the 433 MHz Rako network, sends commands to Rako modules, and receives state feedback. For KNX integration via the Bridge: **Hardware wiring:** RA-BRIDGE powered via 12V DC adapter (included), connected to LAN switch. No direct KNX TP connection — communication is entirely IP. **ETS6 programming approach:** The KNX side of the integration runs on a KNX IP gateway or Home Assistant with KNX integration. The ETS6 project defines group addresses for Rako-controlled rooms as standard KNX lighting GAs (e.g. 0/5/0 = master bedroom on/off, 0/5/1 = master bedroom dim level). However, these GAs are not connected to a DALI or KNX switching actuator — they connect to a virtual device (Home Assistant KNX entity) that bridges to the RA-BRIDGE API. In ETS6, this means: the KNX pushbutton writes to GA 0/5/0 → KNX bus telegram → HA receives it → HA calls Rako API → RA-BRIDGE → 433 MHz command → Rako WK dimmer in master bedroom. Return path (dim level status): Rako WK sends state change via RA-BRIDGE API → HA reads it → HA sends KNX telegram to GA 0/5/10 (status) → KNX room display shows correct dim level. This round-trip introduces 200–500ms latency (acceptable for scene changes, not suitable for strobe or rapid chase effects). For the ETS6 filter table: assign GAs 0/5/x as belonging to line 1.1 (the KNX line where the room display is) even though the actual actuator is HA/Rako. This ensures the GAs are forwarded correctly through any line couplers to reach HA's tunneling connection.

Home Assistant Rako integration

HA has a community-maintained Rako integration (HACS, rako_ha component). It communicates with the RA-BRIDGE via the local TCP API — no cloud, no subscription. **API vs hardware bridge — response time comparison:** The RA-BRIDGE API (TCP) responds in 50–150ms from the HA API call to RF transmission. The actual WK dimmer response adds a further 50–200ms (RF transmission + dimmer processing). Total end-to-end from HA call to light change: 100–350ms. This is perceptibly slower than DALI-2 (which responds in <50ms from KNX telegram to light change) but imperceptible for scene changes initiated by pushbutton. **HA automation structure:** For each Rako room, create a HA light entity (mapped to the Rako room/channel) and a KNX entity (mapped to the KNX GA for that room). Two automations per room: (1) KNX ON/OFF change → call light.turn_on/turn_off on the Rako light entity. (2) KNX dim level change → call light.turn_on with brightness parameter (0–255 mapped from KNX 0–100%). **State synchronisation:** Also create a reverse automation: Rako light state change (from wall keypad press) → send KNX telegram to status GA → room display updates. Without this, the KNX display shows the last command sent by KNX, not the actual state after a Rako keypad press.

Scene synchronisation: KNX 'Evening' scene to Rako

The most important integration in a hybrid KNX/Rako installation is scene synchronisation — ensuring that when a KNX scene fires (from a KNX pushbutton, schedule, or presence event), all Rako rooms respond simultaneously alongside all KNX/DALI rooms. **Configuration example:** KNX "Evening" scene = scene 3, GA 4/0/3 (DPT 18.001, value 3). When a KNX pushbutton sends this scene: HA receives GA 4/0/3, value 3 via KNX tunneling. HA automation checks value = 3 → triggers "Evening scene" action. Action simultaneously: (a) calls Rako API for each Rako room: set room to Rako scene 4 (pre-programmed in the Rako system as warm 40% dimming). (b) sends KNX telegrams to DALI and KNX-controlled rooms (e.g. living room DALI scene via GA 0/0/0). (c) sends HVAC setpoint change (GA 2/0/5, value 20.5°C). (d) sends blind position (GA 1/0/0, value 70%). All commands fire within 200ms of the scene trigger — occupants perceive simultaneous response across all rooms. For the Rako side: in the Rako app, pre-program scene 4 in each Rako room at the correct level. HA stores a mapping of KNX scene numbers to Rako scene numbers (configurable in HA as a configuration variable, not hard-coded — makes future scene changes simple).

Rako Keypad vs KNX pushbutton

The Rako RK-Series wall keypad is a battery-operated wireless keypad with 5 buttons — it sends Rako RF commands directly to the RA-BRIDGE without any KNX involvement. **When to specify Rako keypad:** Bedside position in bedrooms where no KNX wiring was planned — a Rako keypad with double-sided tape or a single fixing screw is installed in hours without any electrical work. The top button raises, bottom lowers, others recall scenes. **When to specify KNX pushbutton:** At the room entry (light switch position) where a single cable run is feasible and aesthetics demand flush mounting. KNX pushbutton commands flow through the HA integration to control both KNX/DALI and Rako zones simultaneously — a single press at the room door controls everything. **Hybrid keypad configuration:** In a bedroom: KNX pushbutton at the door (entry control — on/off and scene) + Rako keypad at the bedside (scene recall and dim without getting out of bed). Both control the same Rako WK dimmers. KNX pushbutton commands: route through HA to Rako API. Rako keypad commands: direct RF to Rako, with HA state update back to KNX status GAs. The occupant experience is seamless — both keypads control the same light, and the KNX room display always shows the correct state.

UK building regulations: Part P note

Part P of the UK Building Regulations (England) requires that "notifiable" electrical work in dwellings be either certified by a registered competent person (registered electrician, NICEIC, NAPIT) or submitted to building control for inspection. Notifiable work includes: any new circuit, replacing a consumer unit, adding a circuit in a kitchen or bathroom. Non-notifiable work includes: like-for-like replacement of switches, light fittings, or socket outlets outside kitchens and bathrooms. **Why Rako avoids some Part P notifiable work:** Installing a Rako WK-series wireless dimmer behind an existing wall switch is like-for-like replacement — no new cable, no new circuit. This is generally non-notifiable. Installing a DALI-2 circuit in a bedroom where no existing cable exists is a new circuit — notifiable. In retrofit projects where the client has a tight programme (cannot wait for building control inspection) or the existing electrician is not Part P registered, Rako wireless dimmers in bedrooms avoid this delay. This is a real commercial consideration in UK renovation projects and is one reason Rako maintains strong UK market share despite the technical superiority of DALI-2. Always confirm with the project electrician and building control office whether specific work is notifiable in the relevant jurisdiction — Scotland, Wales and Northern Ireland have slightly different regulations.