ᐅ Basement Construction, Costs, Cement, Foundation Slab, Reinforced Concrete Walls, Ceiling

Hi everyone! I have purchased a developed plot of land and am struggling with the plans to extend the existing, though very small, building. I would like to add a basemented extension but want to have an idea of the approximate costs beforehand. Specifically, it would involve an excavation of about 4x5m (13x16 ft) to a depth of 3.5m (11.5 ft). Due to the sloped location, I will probably need to use reinforced concrete made of water-repellent material on two sides to prevent unwanted water ingress. I have already considered the costs for stairs and an excavator, so I don’t need those for now. I will use the excavated soil to fill another part of the plot, so there will be no transport costs. But what can I roughly expect for costs related to cement, the slab, reinforced concrete walls, and the ceiling?

I would really appreciate any advice. Please feel free to ask if you have any questions.

Thank you in advance

Sebastian

Hello Wandler,

unfortunately, I cannot provide information about the costs, but I would recommend using water-resistant concrete everywhere. Even if the water only comes from one side, it can still penetrate all around.

Best regards