Buy an existing house - A lot of work for renovation?

Hello everyone,

we are facing a house purchase. We want to move from renting to owning our own home. We looked at a small, beautiful house that we liked right away. The upper floor and attic are ready to move in. There is still some work to do in the basement. The house was built on a strip foundation. In one room there is a floor slab, in the second room there is only gravel on the floor and terrace slabs on top of it. Here I would remove everything and cast a floor slab afterwards.

What confuses me, however, are the walls. On the one hand, it looks like a supporting wall was built, and it seems as if there is some moisture in this room. In this room, the basement is completely underground (slight slope). Furthermore, I am puzzled by the holes in the wall. I am also wondering what their function is. The house is from 1970. Back then, the basement wall was sealed with insulation.

My question is simply the following: Are we buying a lot of work in terms of exposing and resealing? Possibly laying new drainage, etc.?

Regards, Thomas

These are not retaining walls, this is possibly a pathetic attempt to hide the ongoing blooming behind a presumably waterproof wall in front. It does not solve the problem, it only shifts it.... upwards. Capillarity is a silly thing, water wants to evaporate and if it has to crawl up to the next floor to do so because it cannot escape under the Aquafin / renovation plaster / etc., then it will do so.

Getting the basement dry and waterproof will be complicated and expensive. Dig out, seal, put in a sealed floor inside as you say, and drill holes in the walls and inject silicification to close the capillaries. It still will not be 100%.

I once wrote to the realtor about this and received the following answer:

So, the base was constructed for a simple reason:

The actual builder had left the rear cellar full of clay. This provided sufficient statics for the garage.

When the cellar was cleared out, the bases were therefore constructed. The aim was to achieve secure statics. So, it was clearly a matter of the garage’s structural stability and not due to moisture.

I have already mentioned that the father excavated and sealed the house.

According to the brother’s statements, there is a gravel layer under the [split].

Does that sound plausible?

Aha; the garage is accessible from all 3 sides....

And the statement from regarding rising water still stands.

Furthermore, the holes in the wall surprise me. I also wonder what function they have.

To ventilate the basement?

My question is simply the following: Are we buying a lot of work in terms of exposing and resealing? Possibly installing new drainage, etc.?

If you want to use the room for more than it is actually good for now; definitely.

Nevertheless, a construction expert should take a look on site before you buy.

The actual builder had left the back cellar still full of clay. This provided sufficient statics for the garage.


When the cellar was cleared out, the base walls were therefore erected. The goal was to achieve a secure statics. So, clearly a matter of the structural stability of the garage and not because of moisture.

You should have asked the real estate agent right away. In my eyes, the statement is nonsense. How high was the "structural stability-providing clay" supposed to have been back then? Up to the ceiling? I don't understand which structural engineer then proposed half-high walls on three different levels; if there was a risk of buckling, the reinforcement should have been built up to the top.

That the father excavated and waterproofed the house, I have already written.

It doesn’t say it was excavated all the way down, but be that as it may, the moisture damage (no, it is not from before 1970) proves that the waterproofing did not work.

According to the statements of the brother, there is a layer of gravel under the split.

Put a dry newspaper on the split, then one of the slabs on top. If the newspaper is damp after a few days (which I assume from the photos), proper renovation is necessary.

But yes: you ask first, then trust the seller and agent that everything is fine. What else are they supposed to say?