House behind the dam - what should be considered?

In a very recent case, a client of mine purchased a lakeside property. The basement floor, which on the street side is a normal basement, is at ground level on the lake side. Here, the client enjoys a beautiful terrace later on and can quickly dip into the lake and come back out. So... BUT!!! The basement floor is 1 meter above the groundwater and 1.50 meters below the flood level from 30 years ago. Despite several warnings and design solutions for the event of a flood, he refuses to listen and waives flood protection. There are also stubborn builders, but this builder knows that if a flood situation occurs, the renovation work will cost about 200,000 EUR and that the basement rooms will not be usable for months. But he risks it and is supposedly even insured against it. I must also mention that the construction project costs about 2.75 million EUR according to our cost estimate. And he keeps saying he can afford 200,000 EUR, it’s no problem for him. Whoever can afford that much money can live with this risk. But those who only have about 300,000 EUR left for their long-awaited house and really watch every penny when building, there is no help for them; they should build wherever they want and however they want. Simply advising against the purchase is already a proper help for builders who have built before and have much more experience than someone who can’t even assess a property themselves. Don’t be angry but it’s just the way it is!!

Hello,


You sure are quite a character :confused:


This forum is meant to support any construction project, thrives on homeowners’ experiences but does not replace external, personal advice in difficult cases, like yours!

You dream – like many – of building your own little house and want to save significantly at an important point, just because nowadays it’s so trendy to get everything as cheaply as possible :confused: What if one of the statements made here leads you straight into disaster? Who is liable then when everyone comments under a nickname?

Take your questions and consult a building expert in your region and clarify the options for flood protection with him. Since he will give you this in writing, you will also have leverage for the worst case! Of course, this advice costs money; air and love do not fill the expert’s profit and loss account.

Rhenish greetings

I don’t want direct construction advice, just a few tips in case someone has already considered something like this or has informed themselves in this direction. That’s what this forum is for, right? To get initial ideas, isn’t it? And that’s all I wanted. And no discussion about whether I should buy a plot or not. That is my decision after all and has nothing to do with my question.
In Nutshell’s first post there were also just a few rough orientation points. And that’s exactly the kind of thing I was hoping for. That I then have to inform myself in more detail is also clear to me.

And I don’t want to build a little house just because it’s “hip.” After all, we’ve been searching for over 4 years and we could have had something long ago. And unlike most here, I don’t have to save, but rather have quite good equity and good financing. And I don’t think I ever said anything about getting something for free. Unless experience exchange costs something nowadays :confused: Please take it slowly, okay? There’s no need to be this unfriendly so quickly. I will look for a building expert when I am sure to take the plot! Not when I’m just thinking about it (in the first stage)! And so I would have simply wished for constructive answers in a construction forum..... But at least I got a good one.

Perhaps I should just ask my questions more precisely.

Is there such a thing as a waterproof basin for the basement for the ground floor as well? We wouldn’t build a basement in that area anyway.
I have already learned about pressure-waterproof doors and windows.
Which masonry is still the most suitable? Are there special floor slabs that can better prevent water?
Heating and electricity in the upper floor, understood.

And in the last 40 years, there hasn’t been any flooding there. But I would rather prepare for all eventualities. And if it gets serious, I would consult the appropriate experts.

I am currently building a house right next to a small stream. Our flood protection mainly consists of not having a basement and building 35 cm above the HQ100 line. In our case, this is not a big issue, as we only need to add about 30 cm of gravel. However, I cannot judge whether this would be practical behind your dike.

Hello,

I don’t want direct building advice, just a few tips in case someone has already thought about something like this or has also informed themselves in this direction. That’s what this forum is for, right? To get some initial ideas, right? And I didn’t want more than that.

Then you should have kept this sentence to yourself: "And I would ask for reasonable answers. After all, we take house building seriously...." It reads as accusatory, and the response to your question is limited due to this attitude.

And no discussion about whether I should buy a plot of land or not. After all, that is my decision and has nothing to do with my question.

If you ask the users here for their experience, you can hardly expect to receive “only” information that you consider sensible and valuable. Every user has different ideas on the subject; after all, this forum is not a request show.

And I don’t want to build a little house because it’s so “hip.”

You are either a quick-tempered child or still very young; in any case, not proficient in reading! I wrote: "and want to save in a significantly important place just because nowadays it is so hip to have everything as free as possible". This statement is a direct answer to your question. Because—even if a user gives you initial help—this does not replace a careful clarification with a specialist on-site. What worked for one user regarding flood protection does not necessarily have to work for you.

And as far as I know, I never said anything about getting something for free. Unless exchanging experiences now costs something. Please take it easy, okay?

You don’t even need to say that, it emerges from the way you react to the comments here. You write: "IF I buy the plot of land, but only IF we buy it, what we can/must/should consider when building the house!" The shoe is on the other foot! First clarify on site what “possible” additional costs will come to you before you decide to buy this plot of land.

There’s no need to become so unfriendly right away. I will look for a building surveyor when I am sure to take the land! not when I am only considering it (in the first stage)! And therefore I just would have wished for constructive answers in a building forum..... But at least I got a good one.

If you already call me unfriendly now, I want to see your reaction when I really step on your toes; so far, it’s still quite mild. But I can also gladly withdraw from the discussion if you prefer that. Always remember, what goes around comes around ;)

The building surveyor already helps you with the choice of the land, especially since you have obviously decided to build a single-family house in a not uncritical area; a good alternative is also an advanced soil survey. He can tell you exactly—especially if he comes from the region—which additional costs you must expect later with your building project. You can then present the arguments thus raised here for discussion, and only then will you receive, in my opinion, useful answers from similarly affected users.

Rhenish regards

Is there something like a waterproof tub for the basement for the ground floor as well? We wouldn't build a basement in that area anyway.

There is already the problem of buoyancy with sealed basements. With a slab foundation, there is even less contact with solid ground, so with enough water in my opinion, your house will turn into a ship. (see concrete ship)