Do you need LAN cables in the garage?

That also depends entirely on the house.
With a low budget option, I would also skip it and try to find another solution or possibly do it myself.

With an upscale level, with a fancy garage, I definitely wouldn’t do without LAN, unless it is right next to the utility room and the problem can be quickly solved with a drill. ;)

I would say that with upscale equipment or, to put it bluntly, blown wealth, you don’t ask about 500€, you just have it done.

As I said, I would save myself the 500€.

I personally wouldn't do without it. Who knows what it might be useful for in the future. No, they don't have to. For example, we have a Zappi from myenergi. The connection is made using a wireless hub, which is then placed directly in the utility room (of course, it also depends on the distance between the garage and the utility room). But there are certainly boxes that have a LAN connection. It then depends on what kind of box you want.

We have exactly the same combination and the range of the hub is large, but not infinite. I personally would lay at least a duplex or 2 separate (earth) LAN Cat7 cables (hopefully the electrician charging for one or two makes only a 50€ difference?) Sometimes not LAN is needed but just a serial connection (depending on WB / WR), then a LAN connection and all cables are occupied. And that right from the start. So it's already tight. For example, I have 2 wallboxes at the parking spaces and only 2 LAN cables (the solar installer said one LAN per WB is sufficient). Later it turned out that an additional serial connection would have been better (due to the limited wireless range of the Zappi hub).

Just ask the electrician how he arrives at the 500€. He should tell you the material requirements and the amount of work. Of course, I can't really compare with current prices since our construction was about 7 years ago, but back then we paid 100€ for a duplex cable to the furthest corner of the garage. Otherwise, you obviously have to know if you can afford to absorb the 500€.

We are building with a developer. He says because the cable has to go through the building envelope, it is much more effort for him. The problem is either we accept the price or have to do without it. Unfortunately, we are tied to the electrician. We can bear it if it really makes sense. Is it enough if we just have a simple Cat cable installed and, in case more LAN sockets are needed, simply mount a switch in the garage for more ports? CatDuplex costs quite a bit more.

Sorry, but what kind of idiot is the electrician? I can tell you that a 400 METER Duplex CAT7 roll is available for 500€. At our place, the garage is also directly attached to the house and there’s nothing more than a hole in the wall (just like with walls inside the house). (Even though at our place they also run through empty conduits) How far would the connection to the router/server cabinet etc. be? He should alternatively lay an M25 empty conduit for you, you buy length x Duplex CAT7 at the hardware store and have it connected by the installer electrician (if he is an employee of the idiot and not the idiot himself) as part of the installation of the other LAN cables. You get a neck ache reading something like that.

Why does duplex cost significantly more? The effort is the same since both cables are welded together and you only pull "one cable"!? Explain what the € difference is and why.