House construction with developer - electrical and warranty

Hi everyone,
we are building a house with a developer and have just completed the electrical sampling. Initially, we had requested a quote for motion detectors including installation. Since I can buy almost 2 motion detectors online for the estimated price, I asked to remove the detectors and only lay the necessary cables. We then received the following response:

"For the circuits with motion detectors, only the connections were requested. I would like to point out that if you install the motion detector devices yourself, the warranty will be void. It is an intervention in our installation and possibly also violates VDE regulations if the devices do not comply with the standard with VDE certification."

Somehow this is not comprehensible to me. Then the warranty would also be void if you connect a lamp to a light outlet... What do you think about this?

Yes, that’s also the case. If you connect any kind of Chinese firecracker to a light outlet, the warranty is void. He just protects himself.

Yes, understandable, because if it doesn't work, according to the customer it is never his China stuff. On the internet, you get everything cheaper, just not the installation and the warranty.

But when it comes to the warranty or the extra effort to install and adjust the crap, that must not cost anything.

So I would have installed the exact same motion detector 1:1 as he offered me. €100 on the internet vs. €175 from the electrician.

You did not understand. The price includes the labor plus the warranty that he must fulfill towards you. With the dealer, you have to connect it yourself, and the dealer's warranty is of no use to you because he can quite easily claim that a connection that was not carried out by a professional should always be initially questioned. Then you have to prove that your installation complied with all guidelines and standards, and you won't be able to do that after the damage because no expert will certify that for you. There are even insurance companies that then refuse to pay (they have to advance payment first but will recover it from you afterwards).

Thank you for the clarification. Now "auch ich" ;) have understood it.