The construction of a foundation for a greenhouse from a bar begins with digging a shallow trench according to the size of the future greenhouse. First of all, the axes of the greenhouse frame are marked on the ground. For this, a cord and pegs are used, which are driven in at the intersection of the long and short sides of the greenhouse according to the size of each side. Further, stepping back from the axis by 10-20 cm in both directions, the pegs are hammered again, onto which a cord is pulled, limiting the size of the groove in width.