fixed price guarantee

Hello everyone,
I am building a prefabricated house from Danhaus with a basement from Glatthaar. Due to a long approval process with the municipality and a construction site on our local bypass with a full road closure, the construction was delayed by 2 years. Now both companies are demanding a total of about 20,000 EUR extra from me. Danhaus has a clause in the contract that I must pay 0.5% of the amount monthly as a "penalty" for the delay.
I had this reviewed by my lawyer, and these clauses and subsequent price increases are at least in the way they are applied inadmissible. I will take action against this and demand repayment of already paid amounts.
Are there people here who have experienced something similar? I would like to prepare a class action lawsuit.
Best regards, Mohanad

We are not in America where there is a class action lawsuit for everything.

Basically, all fixed prices are limited in time in some form and the client is liable for ensuring that the property is buildable. In case of delays caused by the client, the companies are of course entitled to pass on price increases. A flat rate of 0.5% per month or 6% per year could be challenged, but I would not assume that it would help much in the end. In the end, you will be required to pay compensation according to the construction price index, which is of a similar magnitude, and for the last year tends to be higher.

By the way, €20,000 additional cost for both companies and 2 years delay is not a big price increase. If you just calculate the necessary lawyer fees and the stress... and consider the possibility that you will still have to pay €15,000 more in the end... I would really think carefully about that.

Another question: When you signed the contract back then, what did you discuss with the danhaus representative regarding this clause?

Hello everyone, we share the view of Rumbi441. Ultimately, what is binding is what is detailed in the contract and whether there are possibly any time-related clauses. Due to the currently high raw material and material prices, it is becoming increasingly rare to get a binding fixed price, especially if the start of construction will be delayed by several months.

Hello everyone,
we see it the same way as Rumbi441. Ultimately, what is binding is what is detailed in the contract and whether there are possibly any time-related clauses. Due to the currently high raw material and material prices, it is becoming increasingly rare to get a binding fixed price, especially if the start of construction is still going to be delayed by several months.

The approach here, I think, was rather to question whether the clauses from the contract are valid.

hm I always see something like this critically. Of course, 20000€ is a lot of money, but if you signed the contract today, it would easily be 50-100k more. What if they then try to kick you out of the contract? Or your construction site stands still for 6 months due to "material shortage"? Eventually, the double burden will easily eat up the 20000 extra costs. I would definitely think carefully about it.