Rainwater must be obligatorily infiltrated

NRW Niederrhein 2021: 33 EUR net for normal KG pipe (100er) and max. 10 EUR extra for the KG2000. Incl. installation + disposal, if necessary. The expensive providers, however, also wanted around 65 EUR net for KG2000. 100 EUR all in is therefore a high price, but not completely unrealistic.

On the topic "nicht frostfrei" and with a slight slope: Our house builder led the drainage pipes quite deep out from under the floor slab and left them there. The excavator then had to dig even deeper to lead the drainage with a slope over 30m away... Would have been really tedious by hand ;)

On the topic of being keen on it:
Sure, I would like to leave something to my children that I personally "touched," but as already mentioned,
if the time, the machines, and the expertise are missing, I won’t start trying to do something with brute force.

I understand you, but you shouldn’t overdo it either. Paving is only done at the end, so it doesn’t matter at first whether you lay pipes under pavement or grass. You can read up on the experience. You can rent machines if necessary, some things can also be bought (preferably used) and resold if you only need them for a longer period. Of course, not all tasks are suitable for DIY work, but some are.
I also decided against doing the flooring and painting myself. Simply because with a job and a child, time is valuable and a construction site 45 km away is too far to quickly do something after work. But we will do the garden house, carport, and outdoor facilities ourselves and, of course, also the supply line to the cistern. That really isn’t rocket science.

NRW Lower Rhine 2021: 33 EUR net for a standard KG pipe (100mm) and up to 10 EUR extra for the KG2000. Including installation + disposal, if necessary. The expensive providers, however, wanted around 65 EUR net for KG2000. 100 EUR all in is therefore a steep price, but not completely unrealistic. On the topic of "not frost-free" and with a slight slope: Our house builder routed the drainage pipes under the floor slab quite deep and left them there. The civil engineer had to dig even deeper accordingly, to lead the drainage with a slope over 30m away ... Would indeed be very tedious by hand ;)

This was about rainwater pipes, wasn't it.

Yes, I would never ever lay a sewage pipe myself. If the slurry ever comes up under our driveway, I want to have someone responsible for it, whom I don’t see in the mirror every morning. I will probably lay rainwater pipes myself, we’ll see. But I prefer not to install a cistern myself again. However, mainly because we don’t have much space to create a proper slope for the hole. And steep down - that probably won’t work with the mini excavator or it doesn’t feel safe to me with our sandy soil. Back then, when we were digging out, we already had a wall collapse where one guy was buried up to his waist. It ended luckily without serious harm.

This was about rainwater pipes.

You are right, sorry. I was thinking elsewhere, or rather about our civil engineer who had done both directly....

You are probably right. But I was rather thinking of a similar solution and personally don’t find it ugly or impractical at all ...

That’s exactly how I could imagine the second connection at the other end of the property. That really looks like something.