I am curious. The construction is supposed to start in February 2023 for us. Currently, our contractor is completely relaxed and still has some constructions going on in the area. He said that he naturally has to order the air-to-water heat pump etc. now because of the delivery times. Also, there have been no remarks regarding "price adjustments" so far.
Let's wait and see, the price adjustment also arrived for us at the end of December, construction started in mid-January. If the fixed price period expires before it begins, hardly any company will not take the option of a price adjustment. That would be downright negligent towards their own employees.
Every contractor is completely relaxed. After all, we don't tell our customers: Yes, you can forget the schedule, we will only get some critical components shortly before the final inspection.
Because this honesty is rarely rewarded. So we "play the game," like every other company, and hope to get one or the other component earlier than threatened.
Because let's be honest. If your contractor already started to question the final deadline and pointed out delivery problems... you might still back out, right?