Dirt and rainwater connection - Is the offer fair?

If your house is 10x10m, there are already 30m of piping horizontally, without even having one more meter to the street.

Hi

and even that would already be quite an understatement. well, one meter sideways away from the house and just under one meter up means with 5 downpipes including garage, that's already 10 more meters

Olli

Thank you. I also spoke again with the general contractor. I was not aware that there are 4 downpipes and therefore horizontal rainwater drainage is laid around the house. The initial values were indeed assumed flat rates, without detailed planning. I also find it surprising that 25m is calculated for rainwater. For which house is that supposed to be accurate? Especially since all other values in the rough cost planning were also roughly in line. Only the sewage and rainwater were really way off (more than double).

Look at it positively. Better if an amount of 2,000 € triples than one of 20,000 €

I wasn't aware that there are 4 soil stacks

Then just make two soil stacks and you'll already save 20 meters + x.

If you only have 2 downpipes facing the street, you can manage with 25m of rainwater pipe depending on the property. However, the main contractor also likes to earn a bit extra with such additional work. Example: our main contractor initially estimated about 3,000€ for the wastewater and rainwater connection. In the specific offer, approximately 6,200€ was calculated for about 25m of rainwater connection pipe and 12m of wastewater connection.

See it positively. Better if an amount of €2,000 triples than one of €20,000

There is absolutely some truth to that. And the rough planning still holds up. So we are still well within the calculation, even a few new pieces of furniture are included according to the current status in Excel. And there are not many variable items left open. So I am still cautiously optimistic.

Then just make two downspouts and you already save 20 meters + x.

Can you do it that simply? I have zero knowledge about such planning and have blindly accepted what the general contractor proposed to us. I thought "that's probably how it has to be done." Now on the phone it was often mentioned "there are also many people who allow rainwater to seep away on the property" and so on. Is that possible? Can we do that too? Are you allowed to do that? How do you do that? I would like to read more about the whole topic because I feel uninformed to make a decision, but I don’t even know where to start. I would gladly take a link to a good article if someone has one.

If you only have 2 downspouts towards the street, you can get by with 25m of rainwater pipe depending on the property. However, the general contractor also likes to earn a little extra with such additional work. For example: our general contractor initially estimated about €3,000 for the wastewater-rainwater connection. In the concrete offer, about €6,200 was charged for approximately 25m rainwater connection pipe and 12m wastewater connection.

It was similar for us, although the price per meter is roughly accurate, but in the rough planning there were 10 / 25m for sewage/rain, and in the final offer it was 33 / 65. I am now waiting for alternative offers from other civil engineering companies. If the prices are similar, I would gladly let the general contractor handle it. If it deviates significantly, we will probably have to step back from our "everything from one source" approach. We’ll see.