We were at the carpenter in Poland this week who is making the kitchen, the bathroom furniture, and the dressing rooms.
Beginning of May (this is currently the plan) he will come for the measurement after the interior plastering is finished. Then it takes about 1 month until delivery.
Otherwise, I will be surprised whether the masonry will start on 10.01. The weather forecast says about 5 degrees during the day and 1 degree at night.