ᐅ What are realistic basement construction costs?

Hello,

can you tell me approximately how much a basement (constructed as a waterproof concrete shell) including excavation work might cost?
The basement will be a purely functional cellar, with a flat floor, fully underground, and about 10 x 10 meters (33 x 33 feet) in size. Are there any rough price guidelines?

Best regards,
Sabine

Hello, roughly between 40,000 - 50,000 € (euros). However, many factors influence the price. It is unlikely to be much lower than that.
Best regards, Ronny

That seems too cheap to me. I have already read that a standard basement without excavation easily costs 50,000 euros. But how much does a white tank foundation and the excavation work cost?

Best regards,
Sabine

Hello,
it’s difficult to say. My general contractor offers a (somewhat simplified) waterproof concrete basement shell for the same price as a masonry basement. So, there doesn’t seem to be a big price difference. But if you actually need a _watertight_ basement, we’re talking about additional costs for waterproofed light wells, drainage, and flood-resistant basement windows. That can easily add another 4,000 to 8,000 euros.

The earthworks costs depend on the soil type, and what hits even harder is the disposal of the excavated soil. In an extreme case, if you have to haul away all the excavated earth and buy new sand for backfilling, costs can reach 15,000 to 20,000 euros.

Call the local sand pits and construction waste recyclers in your area to find out their fees for disposing of one ton of excavated soil. For your house size, you will have about 250 m³ (330 yd³) of basement excavation plus around 230 m³ (300 yd³) of workspace excavation. That’s roughly around 750 tons. Around here, disposal costs are about 16 to 17 euros per ton...
And if you can’t temporarily store the workspace excavation on your property, you have to pay a lot for disposal and buying new material later...

Best regards,

Andreas

We received a quote of about 100,000 euros for a waterproof concrete basement as a livable basement (ceiling height, small bathroom, etc.).

Not appealing. It was quickly removed from the wish list...

In my opinion, skipping the basement doesn’t really make sense. You might initially save around 50,000 euros, but then you’ll need a space above ground for the heating system (about 12 m² (130 square feet)) and at least one large storage room. This quickly adds another 40,000 euros to the cost of the larger house. We wouldn’t be able to store our belongings without a basement, so it simply has to be a basement.

Best regards,
Sabine