Hello!
I hope this is the right subforum.
Here is the situation: Our neighbors are currently excavating about 0.50 - 0.6 m (20 - 24 inches) away from our garage to a depth of approximately 1.50 - 1.80 m (59 - 71 inches). Our garage is built on strip foundations. I don’t know the exact depth of these, but I assume they extend to a maximum of 80 cm (31 inches). No underpinning, shoring, or battering/sloping was done during the excavation. About 0.5 m (20 inches) from our garage, the ground is now excavated straight down to at least 1.50 m (59 inches) depth.
According to my understanding of standards like DIN 4123, if no additional underpinning measures are taken, excavation up to 2 m (6.5 ft) next to the garage should only go to a maximum of 50 cm (20 inches) above the foundation base, which is about 30 cm (12 inches) deep. Only beyond 2 m (6.5 ft) distance can excavation be carried out deeper with a proper slope or batter. Otherwise, appropriate section-by-section underpinning should be carried out professionally.
Are my concerns about the structural stability of the garage foundations justified, or am I mistaken? We have already spoken with the neighbors, but they rely on their contractor. If my concerns are valid, what would be reasonable next steps I can take to ensure the stability of the garage? The location is the federal state of Hesse.
I would really appreciate any advice anyone can offer here.
I hope this is the right subforum.
Here is the situation: Our neighbors are currently excavating about 0.50 - 0.6 m (20 - 24 inches) away from our garage to a depth of approximately 1.50 - 1.80 m (59 - 71 inches). Our garage is built on strip foundations. I don’t know the exact depth of these, but I assume they extend to a maximum of 80 cm (31 inches). No underpinning, shoring, or battering/sloping was done during the excavation. About 0.5 m (20 inches) from our garage, the ground is now excavated straight down to at least 1.50 m (59 inches) depth.
According to my understanding of standards like DIN 4123, if no additional underpinning measures are taken, excavation up to 2 m (6.5 ft) next to the garage should only go to a maximum of 50 cm (20 inches) above the foundation base, which is about 30 cm (12 inches) deep. Only beyond 2 m (6.5 ft) distance can excavation be carried out deeper with a proper slope or batter. Otherwise, appropriate section-by-section underpinning should be carried out professionally.
Are my concerns about the structural stability of the garage foundations justified, or am I mistaken? We have already spoken with the neighbors, but they rely on their contractor. If my concerns are valid, what would be reasonable next steps I can take to ensure the stability of the garage? The location is the federal state of Hesse.
I would really appreciate any advice anyone can offer here.
I would like to bring up a recommendation regarding foundations for building on existing structures.
“The new construction will be connected flush with an existing building. According to DIN 4123:2011-05, new foundations adjacent to existing ones must be founded at the same depth as the existing foundations, or existing foundations with deeper foundation bases must be underpinned section by section using concrete replacement elements.”
Therefore, as already mentioned, contact the building authority and arrange for prompt backfilling. I always appreciate photos!
Best regards
“The new construction will be connected flush with an existing building. According to DIN 4123:2011-05, new foundations adjacent to existing ones must be founded at the same depth as the existing foundations, or existing foundations with deeper foundation bases must be underpinned section by section using concrete replacement elements.”
Therefore, as already mentioned, contact the building authority and arrange for prompt backfilling. I always appreciate photos!
Best regards
G
Gerddieter15 Sep 2025 10:54Until the authorities get moving, I would inform the site management and the client in writing that you expect an immediate halt to construction work on your garage wall until the structural inspection has been completed.
As you say—once the pool has been installed, they can say a lot about what they have done and secured there, and it will no longer be easily verifiable...
As you say—once the pool has been installed, they can say a lot about what they have done and secured there, and it will no longer be easily verifiable...
tomtom79 schrieb:
As far as I know, a pool is not allowed right on the property boundary,hanghaus2023 schrieb:
In my opinion, in Hesse pools are generally not allowed to be built within the setback area.hanghaus2023 schrieb:
In my opinion, in Hesse pools are generally not allowed to be built within the setback area. The Hessian Building Code (HBO) requires a minimum distance from the neighboring boundary for swimming pools, which are considered structural installations. This distance is usually 3 meters (10 feet), unless the development plan or other regulations specify different rules.That’s correct! Structural installations (pool) require a setback area. The construction is likely exempt from formal approval (up to a certain size), but that does not mean exemption from regulations. All legal requirements must be observed. @Cronos86 this is probably not about foundation work for a building, but simply an excavation for a pool, which from the neighbors’ perspective is well located next to the OP’s garage.
If there is an imminent risk, I would call the official police, as they can possibly enforce a temporary work stoppage until the matter is resolved with the neighbors/building authority. While they may not be fully familiar with the state building code or exempt building projects, they should be able to assess the urgency if it is explained in simple terms.
That way you avoid being seen as simply complaining, and the communication gains some security.
H
hanghaus202315 Sep 2025 13:48I always wonder why no picture or sketch is posted here? It’s hard to visualize the space so close to the garage. From the description, the garage would have to be sinking.
A
ajokr202515 Sep 2025 15:46hanghaus2023 schrieb:
According to the description, the garage should already have settled.It should have foundations under the walls on at least three sides. Only one side is now more or less hanging in the air. If the garage walls are made of concrete, they also support each other. But that is not acceptable.N
nordanney15 Sep 2025 16:03ajokr2025 schrieb:
It will probably have strip foundations under the walls on at least three sides.Depending on the type of garage, it can also be just two strip foundations.Similar topics