Costs of earthworks without basement

So the building consultant estimated about 18,000 euros (only earthworks and sewer works). Now the cost is supposed to be 32,000 euros. What did he estimate well there? Of course, he couldn't have known that the ground is too soft. So presumably, that is the buyer's risk? Is there a way to approach the seller (real estate agent) about this? He sold a fully developed plot which is somehow defective... if you can see it that way...

Hello,

So the construction consultant estimated about 18,000 euros (only earth and sewer works). Now it is supposed to cost 32,000 euros. What did he estimate well?

You previously wrote that he estimated TEUR 15 for the earthworks; this amount was well calculated. For the pure sewer works, you can calculate another good TEUR 8-10.

Is this therefore probably a builder's risk?

Yes. That is why I always point to the position of incidental building costs TEUR 35 - 40 and additional foundation costs TEUR 8 - 10!

Is there a way to approach the seller (broker)? He sold a fully developed plot which is somehow defective... if you can see it that way...

No, it is not. You bought a plot that the broker offered you. He (the broker) cannot know what the soil conditions are; unless he was informed about them beforehand - which obviously is not the case here, otherwise he would have informed you.

The plot is also not "defective" – it is one of many that entail additional foundation costs; nothing more and nothing less.

Kind regards

The house has a granny flat on the ground floor, so it is somewhat larger. I still have to look at the soil report again, but as far as I remember, 20 cm of topsoil, then after the topsoil another 70-80 cm of excavation, and soil replacement up to 1.40 m. Concrete slab, no basement. The property was bought from a real estate agent. Should have done a soil report beforehand

2.40 m deep hole? Or 1.40 m deep in total? We had to fill and compact about 1.20 m with a mix of gravel-sand-aggregate over an area of 300 sqm. Total costs were just under €12,000. Almost 650 tons of material. If you really have to go 2.40 m deep, the price is clear.... then you might want to consider whether the granny flat could perhaps be exchanged for a residential basement. In the end, it might be about the same price. Information without guarantee (*bang*)

The only one you can turn to is yourself. You buy a pig in a poke and complain afterwards. Neither your construction advisor nor the realtor has to know what the ground beneath your property looks like. The only exception is if you can prove that the realtor already had a soil report. Because then he would have had to inform you. Otherwise, bought as seen.

Well. Sad but true. I had once asked the realtor orally if there were any special features regarding the property in terms of a basement, which he denied. I thought oral communication wouldn't help anyway. Well, then it will just be more expensive. Maybe a basement with a [WU Wanne] is worth it after all (or it's not that much more expensive anymore). I need to have the price determined. Thanks for the information.

Well. Sad but true. I once asked the realtor verbally if there were any special features regarding the plot in terms of a basement, which he denied. I knew verbal communication was useless anyway. Well, then it'll just get more expensive. Maybe it’s worth having a basement with a waterproof concrete shell (WU shell) after all (or it’s not that much more expensive). I have to get the price determined. Thanks for the info.

If soil replacement is the cost driver and you can finance most of the basement costs with the savings from avoided soil replacement: build with a basement.

Better to spend 40 grand on a basement than 32 grand on soil replacement. The basement increases the value of the house; soil replacement does not.

(Numbers above are fictitious, just for illustration)