The foundation of the Home Automation solution is a set of devices which conform to the KNX standard which is generally used in larger commercial or hospitality projects but which meets Marsh Flatts Farm’s requirements very well:
- When switching mains voltage the paramount requirement is electrical safety so it’s important to use commercially manufactured and certified devices, installed by a qualified electrician
- There are a lot of competing, proprietary solutions on the market but I didn’t want to be reliant on any single manufacturer to offer a suitable range of devices (and integration options) and maintain those for the lifetime of the installation
- KNX is unusual (in a good way) in that it is not specific to one manufacturer and it’s normal to mix-and-match devices from different manufacturers within a single installation
- Many home automation solutions are intended to be retrofitted to existing, ‘traditional’ electrical installations which have hard-wired wall switches and light fittings – but in a new-build project there’s no reason to hard-wire traditional mains-voltage control switchgear
- If there’s no hard-wired switching for e.g. lights and blinds there’s also no fall-back in the event of problems with the home automation system – so it needs to be reliable
- KNX has a very robust ‘distributed’ system architecture with no central controller
- I wanted something that would be instantly recognisable to home automation professionals, mostly from a property resale standpoint (on the assumption that anyone buying the house would be less hands-on and would want to hand over any updates to the KNX control logic to a specialist)
In very high-level terms the KNX installation consists of a dedicated KNX ‘bus’ network using a specific type of twisted-pair wiring (KNX TP1) with various input and output devices mounted in electrical cabinets around the House. With the addition of the separate Outbuildings in 2025, a second KNX ‘bus’ was installed there, electrically separate from the ‘bus’ in the House – but integrated so that devices can be controlled in both buildings.
Mostly I am using KNX devices from German manufacturer MDT which I have found to be of high quality, good value and with great functionality and documentation. A good supplier for these is eibmarkt in Germany.
KNX installations need to programmed with a Windows application called ETS which is firmly aimed at home automation professionals rather than end users. The full version, ETS Professional, is expensive but there is a cut-down version, ETS Lite, which is rather more affordable but can only be used with (any number of) projects containing up to 20 KNX devices.
As of ETS version 6, a third license tier has been added – ETS Home – which caters for a single project containing up to 64 KNX devices, for the same price as ETS Lite.
There is (was?) another option, ETS Inside, which is more intended for end users and did support other operating systems than Windows – notably Linux.
There are a few further pages with specific configuration notes for some of the KNX devices:
KNX by Marsh Flatts Farm Self Build Diary is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.