There are 18!!! full closures being offered.. Just the activation and deactivation make up 50% of the offer. Originally, 2-3 days were mentioned..
Update:
It is correct that 50% of the offer was charged for driving there, putting up signs, driving away, and coming back in the evening to take down signs.
My site manager told me that they "generously" estimated the days because the property is small and he is not sure if everything can be stored on the property at the same time and whether or not additional closure times might arise if material is delivered or something similar.
So the calculation is a "worst case" calculation.
He also told us that we can put up and take down the signs ourselves. The first time, the company comes, puts up the signs, we photograph the positions etc., then we get a schedule from the site manager where we receive his instructions on when the signs must be put up again and for how long.
Since we live nearby and have family + friends nearby who might be able to help monitor (that the signs are not knocked over etc.), we will take this on as EL. After all, it is almost 4500 euros..