ᐅ Building Site – Foundation Recommendation

Good day,

I need your help.

I have a plot with an old building and now want to construct a semi-detached house there.

It will be a timber frame house, not a solid masonry building. For this, a soil survey was necessary, which I have commissioned.

The soil looks like in the picture: one side is quite okay, but the other has significant peat layers.

Are there alternatives to a very expensive pile foundation? In this neighborhood, hardly any house has a pile foundation because most were built in the 1990s, when less attention was paid to this.

I would be grateful for any alternatives. However, soil replacement is not an option, as groundwater is expected from a depth of 1 meter (3 feet).

Thanks in advance for your creative suggestions.

🙂

Hello and welcome,

the soil investigation report should include a foundation recommendation. In my opinion, this is independent of whether the building is constructed with solid materials or a timber frame. Pile foundations are expensive. We used a slab foundation with frost protection edge insulation, but in our case, the groundwater level was lower. Again: check your report, and if nothing is mentioned about this, ask the surveyor.

Should the slab foundation be kept or replaced? However, you won’t find a construction company that goes against the recommendations in the soil report.

The recommendation, of course, is that a piled foundation should be used.
Therefore, I’m asking if anyone might know of any alternatives?

The construction companies either follow the recommendation or say that you have to take care of everything yourself up to and including the ground slab, which naturally also has implications for the warranty.

The old strip foundation is to be removed and replaced completely with a new one.

Thanks in advance for your answers.
It’s a shame if there really is no alternative, especially since 60 houses around here didn’t require a piled foundation – but oh well 😀

Of course, there are alternatives. However, no one can advise you on this because a) no one knows the exact circumstances, and b) nowadays warranties play a significant role, and these are only provided if you follow the recommendations of professionals who specialize in this field.

raven_on schrieb:

The recommendation obviously states that a pile foundation should be installed.
So I’m asking if you might know of any alternatives?

The construction companies either follow the recommendation or say that you need to handle it yourself up to and including the concrete slab, which naturally also affects the warranty to some extent.

The old strip foundation is supposed to be removed and then completely rebuilt.

Thanks in advance for the answers.
It’s a pity if there are no alternatives and 60 houses around didn’t need a pile foundation—but oh well 😀

Normally, the soil report also includes an alternative recommendation from the geotechnical engineer. If this is missing, then maybe there really is no alternative? Please contact the geotechnical engineer or geologist; they are the specialist for this and have the samples in front of them. This usually doesn’t involve any extra cost.
What I don’t understand is that soil replacement wouldn’t be possible due to the water conditions. From a non-expert technical point of view, I find that hard to imagine. The excavation would just have to be kept dewatered during the entire construction period. Otherwise, I do not see how you can switch to a cheaper solution as you hope.