Hello everyone,
We are close to submitting our building permit / planning permission, and our builder claims that we are required to plan and install a backflow prevention system.
We understand this in principle. However, what really isn’t clear to us is why we are not allowed to install a backwater valve for sewage and are allegedly required to install a lifting station (sump pump system).
Here is the situation:
The plot is completely flat, and rainwater is not allowed to be discharged into the sewer system anywhere in the development; it must drain into an infiltration pit. Our ground floor is located approximately 30cm (12 inches) below the last backflow level in the sewer. The property / development is situated on top of a hill, so no water is flowing downhill toward it; in fact, water drains away quickly.
This means that for a rare event that might occur once every five years, when the sewer cannot handle the rainwater, we are supposed to install a lifting station.
In our opinion, a backwater valve would clearly be sufficient in this case, not a lifting station. The lifting station serves a different purpose for us. Furthermore, this system is not allowed to be installed outside the building, so we would have to have a flap and the system under the slab in the utility room.
The whole setup is estimated to cost about 7,000 euros (around $7,700) without any excavation work.
Are we being too simplistic, or is the builder correct?
By the way, for insurance purposes, a backflow prevention device is important. A flap valve alone should be enough and certainly achieve the same effect.
Thank you for your opinions.
We are close to submitting our building permit / planning permission, and our builder claims that we are required to plan and install a backflow prevention system.
We understand this in principle. However, what really isn’t clear to us is why we are not allowed to install a backwater valve for sewage and are allegedly required to install a lifting station (sump pump system).
Here is the situation:
The plot is completely flat, and rainwater is not allowed to be discharged into the sewer system anywhere in the development; it must drain into an infiltration pit. Our ground floor is located approximately 30cm (12 inches) below the last backflow level in the sewer. The property / development is situated on top of a hill, so no water is flowing downhill toward it; in fact, water drains away quickly.
This means that for a rare event that might occur once every five years, when the sewer cannot handle the rainwater, we are supposed to install a lifting station.
In our opinion, a backwater valve would clearly be sufficient in this case, not a lifting station. The lifting station serves a different purpose for us. Furthermore, this system is not allowed to be installed outside the building, so we would have to have a flap and the system under the slab in the utility room.
The whole setup is estimated to cost about 7,000 euros (around $7,700) without any excavation work.
Are we being too simplistic, or is the builder correct?
By the way, for insurance purposes, a backflow prevention device is important. A flap valve alone should be enough and certainly achieve the same effect.
Thank you for your opinions.
B
Bauexperte20 May 2016 19:29@ Andreas
You might find it hard to believe, but there is not just one mandatory DIN standard called "haumichtot"; there is also a backflow prevention manual. Whether it always makes sense to follow it is certainly debatable, but you should adhere to it nonetheless.
The single-family house in question cannot flood through the front door if the planner includes appropriate measures in the design; one or two entrance steps would be one such measure.
Bauexperte
You might find it hard to believe, but there is not just one mandatory DIN standard called "haumichtot"; there is also a backflow prevention manual. Whether it always makes sense to follow it is certainly debatable, but you should adhere to it nonetheless.
The single-family house in question cannot flood through the front door if the planner includes appropriate measures in the design; one or two entrance steps would be one such measure.
Bauexperte
andimann schrieb:
One more thing, if
this really is a developer:
that is _HIS_ problem, not yours! You have purchased a house and land at a (hopefully) fixed price. If he overlooked during planning that a lifting station is required: HIS bad luck! He must deliver a house that complies with the regulations at the agreed price.
Best regards,
AndreasThe question remains whether, and if so from when, this becomes the developer’s problem. In fact, it should be his problem as soon as the fixed-price contract is signed and notarized.S
Sebastian7921 May 2016 07:25Bauexperte schrieb:
A single-family house like the OP’s cannot be flooded through the front door if the planner includes appropriate measures; one or two entrance steps would be one such measure.However, the OP’s ground floor would then no longer be below the backflow level – Andreas is right when he says that in the event of a problem, the OP would have a completely different issue here.
At least if, as is often the case, the backflow level corresponds to the finished street level.