Screw foundation as a cost-effective alternative to a slab?

Hello everyone,

our architect has proposed a screw foundation for our wooden house. The house stands with a wooden floor on screwed sleeves, similar to a pile construction. The supply lines receive a small, frost-proof enclosure. Mainly proposed to save costs, but for us also an argument that the area remains fully removable. We have no special conditions on the property. Gravelly soil with a slight slope. No groundwater. Does anyone have experience with this type of foundation? What are the advantages and disadvantages? I am just surprised that there is hardly anything to be found about it. Why don’t more people use this in timber construction since it is apparently much cheaper?

Greetings from the South

Hello, I would build my next house like this ;) ... On my brother's property, there is a TinyHouse which is founded exactly like this. Here, primarily to build cost-optimally, but also clearly for ecological reasons. Concrete (cement) has the largest share of CO2 emissions worldwide ...

Unfortunately, I personally have no experience other than the exterior view of the above-mentioned foundation. I believe I have heard that this construction method is more widespread in the Netherlands.

I still have some concerns about whether any critters might nest under the house since it stands on stilts. Our architect says it is so drafty down there that nothing would want to go in. Other concerns would be the durability of the galvanized screw sleeves in the soil.

I still have some concerns about whether any critters could nest under the house since it is built on stilts. Our architect says it’s so drafty down there that nothing would want to go in. Further concerns would be the durability of the galvanized screw sleeves in the ground.

These concerns are unfounded. Houses built on stilts are state of the art. A so-called "crawl space" that is constructed closed helps against these concerns. The galvanized screw anchors are also nothing new. Unfortunately, this kind of technology cannot establish itself in Germany because it has no lobby. In the end, I decided against this technology for my carport because the costs would have been too high in my case. For a larger number of anchors, it is definitely an efficient solution. Search for screw earth anchors. You’ll find quite a lot.

The procedure is proven and we would have used it if our property had allowed it. Nice that your architect thinks along and doesn’t just offer the 08/15 standard.

Hello,

Our architect says it's so drafty down there that nothing wants to go in.

I would take at least this statement with great caution. I once had the pleasure of having my office in such a construction. You could sometimes hear something moving under your feet. But it got even better... At some point, myxomatosis (rabbit disease) broke out in the area and the creatures retreated under the bungalow to die. We had the smell of decay in the offices for weeks! Not funny!

Technically, this may indeed be a good solution; most houses in the northern latitudes (permafrost soil) are built like this. But it must be absolutely certain that nothing can crawl underneath!

Best regards,

Andreas