Prefabricated garage - concrete or steel? What is recommended?

We have not made a final decision yet, but if so, it will be a concrete garage. Interestingly, the offers for steel vs. concrete garage were almost the same price. Concrete gives a more premium impression to us.
However, we are currently considering just making a carport. The garage (and of course the carport) would be located directly next to our utility room. I would rather not build over the supply lines. It probably isn’t even possible. We still need to clarify that.

The garage (of course the carport too) would be located directly next to our utility room. I would be reluctant to build over the supply lines.

Oops, I hadn’t even considered that when looking over your plans :-( That is of course one more argument "in favor of a steel garage", then you simply remove the paving if you need to dig, and in the worst case you can screw the whole thing apart.

No no, we don’t like the steel garage at all. We’d much rather have the carport along the entire side including the entrance canopy. That way, a small window in the utility room will also work.

It may be that you are not allowed to build over the supply lines at all. That was the case for us. We (or rather the municipal utilities) rerouted the fresh water pipe specifically AROUND the carport (double carport + equipment room).