ᐅ New Semi-Detached House – Is Investing an Extra $10,000 Worthwhile for a Smart Home?

Hello everyone,

we are currently planning the construction of our half of a semi-detached house. Initially, I was considering a KNX solution for home automation, but the reality as homebuilders is catching up with us, and the budget is getting tighter. Due to the plot, we are tied to a construction company that handles all trades (including electrical) with their own staff. The contract is expected to be signed soon.

The construction company seems to have limited expertise regarding smart home systems, so I’m now considering how to best proceed.

At the moment, the plan is for conventional electrical work (about 8,000 EUR), plus additional services for almost 4,000 EUR net to install a LAN connection in every room and reach a total of 100 power outlets and 20 lighting points (there may still be some missing).

We still have about 10,000 EUR left, so the entire (smart) electrical installation can cost around 22,000 EUR. We have also planned 13 roller shutters / blinds, which — for now — will have conventional electrical control.

Requirements - Must Have:

• Lighting:
• Central control of lights (preferably all, if necessary by floor, room, or selected areas); partial dimming
• Shading:
• Central control of roller shutters / blinds with automated shading
• Power:
• Make approximately 10+ power outlets switchable

Nice to Have:

• Avoid residual current devices (RCDs) if justifiable via smart home (I do not intend to actively control heating)
• Connection to controlled residential ventilation system
• Integration of voice control
• Window contacts
• Visualization
• Presence detectors
• Sonos integration
• Intercom system integration (Doorbird, Busch Jäger Welcome)
• Alarm system functionality (via presence detectors / sensors, possibly also a proprietary system, e.g. Busch Secure@Home)

Options:
1. Conventional wiring plus standalone radio solutions (this is what we currently have in the rental apartment: Somfy roller shutters, HUE lights, etc.), integrated into a common visualization platform (such as ioBroker and others)
2. Proprietary system, currently the favorite is probably Free@Home with central actuators, allowing a possible later switch to KNX if needed. Alternatively, Homematic Wired might be an option.
3a. KNX with the must-haves and preparation (cabling) for nice-to-haves / as much as possible
3b. KNX with must-haves, nice-to-haves via radio solutions / gateways, integrated into a common visualization (ioBroker and others)

I’ve read a lot about this but somehow keep going in circles...

Do you have any advice on how to best approach this now? Should I create a room schedule and request various offers for options 2 and 3? Should I look for a qualified system integrator / smart home expert who can offer both options 2 and 3? Or is this basically unrealistic with the given budget, and I should focus on option 1?

Although construction doesn’t start until summer, if I want to try to contract the electrical trade elsewhere, I only have about 4 weeks left.

I am not completely ruling out KNX and could also imagine doing some work myself. Has anyone used a solution where they hired a planner, had the control cabinet assembled and shipped, then had the construction company’s electrician install all the wiring, and finally configured everything themselves?

Many thanks in advance!

It’s not impossible. You can do part of the work yourself and initially skip some features. Lighting and roller shutters could be installed later. Then gradually complete everything else.

You will realize that many additional costs may arise during the build and every penny will count.

My opinion: If I were you, I wouldn’t completely give up on the KNX system, but rather put it on hold for now. You could invest in the cables and preparation so that KNX can be implemented later.

Which state/province are you from?

I am currently leaning toward your option 3a with a very similar budget.
Next week, I will talk to the electrician about the plan.
I will also try to convince him to consider the option with external distribution design and construction, as this would allow an experienced professional to handle an important part.

lin0r87 schrieb:

Which federal state are you from?

Berlin 🙂

Regarding putting KNX on hold / only preparing the basics, that would mean conventional wiring, which likely leads to significantly higher costs later, right? You often hear that it’s not really practical. For me, that would be more like option 1 at the start, just to have at least some central control in the house.

@RotorMotor please feel free to share what the outcome was. I also want to talk to the electrician from our construction company soon. The question is whether the pricing adds up. From what I roughly calculated and seen: planning around 2,500 EUR (?), main distribution board all included about 5,000 EUR (?), then not much left for the electrician, and at least a simplified ETS version is also needed. Hmm.

You can also install conventional electrical wiring including "KNX preparation." This requires more cables than implementing KNX alone, but still fewer than having both conventional wiring plus KNX on top. Of course, this means you will gradually have to rewire everything, but unfortunately, there’s no other way. Generally, this would be more like "decentralized KNX," which tends to be more expensive than centralized systems because you cannot use multi-actuators.

By the way, there is also KNX-RF, which works without a bus cable. It is still kind of KNX...

Giggz123 schrieb:

Requirements - Must Have:

• Lighting:
• Central control of lights (preferably all, if necessary by floor, room, or selected areas); partial dimming
• Shading:
• Central control of roller shutters / blinds, automated shading
• Power:
• Make about 10+ outlets switchable

Have you looked into Shellys? They might be sufficient if everything else remains conventional.