Retrofitting existing standard installation in a 40+ years old house

Are there any good practices when retrofitting an old house with velbus? I.e. where to put relays for lights - close to the push button and use existing cable to the lamp or close to the lamp and add the bus cable?

The answer to that is…

Put them where they fit.

The beauty of Velbus is that you can have as many cabinets housing the din modules are you need.

For example, my own home is >140 years old and we have 4 cabinets hidden around the place.

If all you want is switching, the tiny single Channel universal module can almost be hidden anywhere.

Dimming is harder, as you need a DIN rail housing.

Either 2DIN per VMBDMI-R for a single circuit or 6DIN for a combination of a VMB4DC and 4 x Finder 15.11

(Not including any RCBO / MCB that might be required for local regulations)

Heating control is easy if you’ve got a manifold, as the relays can be placed beside them.

If you can only put an actuator at each heater / radiator, then there are a few options.

Whatever you do, you’ll need a 2-pair EIB bus cable to link everything together. Buttons / glass panels / output modules etc.

I’m happy to discuss ideas with you, as I’m sure everyone else on here is.

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Thank you! I’ll be back with questions as soon as I move into the house (hopefully soon).

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We have an “old” house from 1998 and did an extension in 2015. The extension is all Velbus. Some parts of the “old” house close to the extension have also Velbus fitted.

The issue is not where to put relays and modules. As MDAR says, these fit everywhere. The issue I found is cabling. The EIB cable is too thick to pull together with current carrying cable in the same half inch tubing. Anyway, that would be bad practice, having 220V next to low voltage and comms in the same tube, so I did not.

What I was able to do is to remove the old coax cables for Radio/TV and replace these with a combination of UTP and EIB. But there is only so much you can do without stripping the house.

The upstairs is all old house. There might be a way because the floor of the upstairs / ceiling of downstairs is concrete profiles and the builder did all the distribution in the wooden ceiling of the upstairs. So it is conceivable to strip the attic insulation and rerun cables in the existing pipes. And if needed add a pipe from the ceiling down to a panel if needed. But that is so much work I chose to leave in the old stuff.

Velbus over Power Line Connection is the answer. Who knows, it may come in the future. But I doubt Velleman will invest in this. If I were to manage Velleman, I may consider doing this would give me the unique position of being the only on the market that can easily refurbish existing houses and buildings.

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Good observations.

To decode that, are you saying that the only real obstacle is getting a Velbus connection between your loft space (and upper floor lighting etc) to your downstairs system?

If you have a LAN cable between the two points, that would be best or you can use a WiFi version of the following…

@jeroends created an amazing Velbus to TCP server, which works incredibly well.

But what isn’t know well is that it can also be put into Client mode and bridge Velbus networks.

In essence, you’d create an isolated Velbus network in your loft space with it’s own VMBRSUSB, when you’re happy that it’s all working, connect a very simple Debian based mini computer with nothing more than VelServ in client mode, connecting to your main system over LAN.
(This assumes you have a bigger / another mini computer on your main system that is running VelServ or Velbus-tcp, as a network Velbus server)

Once linked, your whole house will appear as one big Velbus network.

This same concept can be used to link between the remote buildings.


All great options. I like to keep things native and simple.I discussed options as you are proposing with the Velbus product manager (Kris) on many fairs I visited. He says it is possible but not supported by Velleman, so issues may arise and you would then have to resolve those yourself.

I don’t mind as long as I am around. But my wife is already scared of Velbus as it is now, saying that if she were to survive me, she would have no idea how to deal with any issues. So she would need to call an electrician. I’m pretty sure most electricians can replace modules and program them in. But VelServ?

I do not mean to be disrespectful. Some electricians out there are really smart. But the majority would not know how to deal with VelServ on a PI.

I did build a complicated thing for the EV charger using Smart Gateway, MQTT, WiFi, Synology NAS and OpenEVSE. If that falls apart, my wife can still charge the EV as with a simple street charger.

Also I was looking at what the advantage may be of having Velbus upstairs versus the work and the cost. There was only one thing that made it worthwhile: my wife would like a button to turn on all the lights from her bed when scum is breaking in our house. We’ve already had Eastern European scum break in twice. We are more protected now. Over the last years we can see damage done trying to break in and because it got too difficult for them they decided to go break in next door. So the urgency for this use case has diminished quite a bit for now.

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That’s easy enough to add with a wide range of stand alone buttons that could be linked with HomeAssistant / NodeRed / openHAB etc

But I totally get what you are saying about a partner needing to have a fully working system for many years to come.

We can all relate to that.

I’m just glad that the only time I have issues with my Velbus system is when I try to do something new and exciting with it.

My lovely lady knows that there might be a day or two of me fine tuning the configuration, but after that, it’ll be rock solid.

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Agreed. Velbus is rock solid. Probably the best system on the market by a significant margin.

And I do appreciate that the Velbus team is not adding functionality introducing bugs and creating problems, but want the system to stay solid.

I work with the OpenEVSE guys for the Charger firmware on GitHub. The legislation is changing fast so the features need to change at a break neck pace. Keeping everything working properly in all conditions can be a challenge… so I do appreciate Velbus stable and solid!


I have considered a different option still. Niko - and probably others, but my old house installation is Niko - have RF switch panels you can put on a flat surface everywhere. They control a relay module that receives the RF and fits in the pots in the walls where old mechanical switches are. They are intended to switch 220V AC. These could be used to close a circuit on a switch sensor that is part of Velbus. That can help making recabling simpler.

There are two downsides though. One is the RF panels run on a coin battery and that runs out every two years and needs replacing. You don’t have that with Velbus. The second is that I do not know if the AC relay is reliable for small DC current switching. It was not designed for that and the contacts may end up oxidized or something like that.