Seven questions before you sign.

1. 01

   Can you show me two or three finished jobs the size of mine?

   Why it matters. Working with KNX says nothing about the scale someone has actually delivered. A 120 m² home and a 1,000 m² villa with a plant room have very little in common in topology, device count and coordination with the other trades.

   Good answer

   Specific references, with location and year, and a willingness to let you speak to the owner or the architect. Better still if some are documented by a third party (KNX Association, a manufacturer, trade press).

   Red flag

   Catalogue photography, projects that can never be named "for confidentiality reasons", or references that turn out to be far smaller than your job.

2. 02

   Do I get the ETS file with the programming when the job is done?

   Why it matters. The ETS project is the living record of the installation: without it, changing a scene or adding a circuit means reprogramming blind or starting over. This is the exact point where it is decided whether you are tied to one company for the next twenty years.

   Good answer

   An unqualified yes, in writing and inside the contract, with the file updated to the last change and the group address documentation included.

   Red flag

   "The ETS is ours", "we hand it over if you stop working with us", or any variant that turns documentation into a retention tool.

3. 03

   Who exactly does the programming, and are they KNX certified?

   Why it matters. Part of the trade sells KNX and then subcontracts the programming to someone who never appears again. When something fails two years later, nobody knows why it was built that way.

   Good answer

   A name and a verifiable KNX Partner certification, with a commitment that whoever programs the system is who handles incidents afterwards.

   Red flag

   Vague plurals ("our team handles that"), with no ability to say who signs off the programming or what training they have.

4. 04

   How do you integrate the pool, the heat pump, the PV and the charger?

   Why it matters. This is where engineering shows. Lights and blinds can be done by anyone with KNX; the plant room requires speaking Modbus or BACnet to third-party equipment and understanding how it actually operates.

   Good answer

   They name the protocol for each piece of plant, explain what can genuinely be read and what can be commanded, and flag the limitations before signing.

   Red flag

   "The pool company handles that separately", or promises of full integration made without having looked at the equipment documentation.

5. 05

   What keeps working if the internet or the server goes down?

   Why it matters. A system that needs the cloud to switch on a light turns any outage at an external provider into a fault in your home. The KNX bus is decentralised precisely to avoid that.

   Good answer

   The essential logic lives in the bus and in the devices themselves. Without internet you lose remote access and notifications, not control of the house.

   Red flag

   An architecture where everything goes through one server or a cloud app, and where the wall keypads are really radio remotes talking to that server.

6. 06

   Will you quote it line by line, with make and model?

   Why it matters. A single lump sum cannot be compared or audited. Line items show how much is hardware and how much is engineering, and whether a cheaper offer saves money by dropping functions or by dropping equipment quality.

   Good answer

   An itemised quote with commercial references, quantities, and the programming priced separately from the hardware.

   Red flag

   A closed turnkey figure with no detail, or a bill of materials that quietly changes brands halfway through the job.

7. 07

   What happens after handover, and who answers in August?

   Why it matters. An automation system lives for twenty years and gets extended several times. The real value of a supplier shows in the second extension, not at commissioning.

   Good answer

   A clear maintenance agreement with response times, and the ability to work on the installation remotely without having to reprogram anything.

   Red flag

   No after-sales at all, or maintenance that depends on one specific person with no structure behind them.

Awards and third-party coverage

You do not have to take our word for it.

Keep reading

• Luxury villas in Tenerife →
• Lighting and DALI control →
• KNX home automation in Tenerife →