ᐅ Constructing a cellared basement in clay soil

I am interested in medieval construction techniques and want to build a cellar pit in my garden. I have already excavated the hole, but despite the heavily clay-rich soil, water seeps into the cellar from the surrounding ground. How can this be sealed effectively using simple, authentic methods?

You cannot prevent water ingress with simple methods; in modern construction, the basement wall is sealed from the outside, but you will not be able to make a pit watertight. I believe the groundwater level is too high for your purposes.

We have also built a so-called cellar with ventilation holes under our garden shed. In my opinion, this is the best way to create a practical cellar for storing wine, beer, and vegetables.
What exact problem are you experiencing?
I assume the cellar is not finished yet?

I’m just going to write down some thoughts, since we also have a damp clay soil.
As soon as you start digging, water collects in the pit. This happens because the pressure inside the pit suddenly becomes lower than the pressure in the surrounding soil. The damp clay releases its water, but it’s not groundwater.
The question is, what should the basement look like? Should the walls be masonry? What about the foundation?

So, we are currently having our house built by the Lindemann Group, and the shell is already up. However, it looks like we will have to wait until next year for it to be "turnkey." I don’t think you can really generalize about that... Just trial and error and learning along the way 😉