There exists a general rule that in the absence of an agreement or statute an excavator cannot recover expenses incurred in protecting adjoining buildings, for the reason that he or she is a volunteer in such cases.  All expenses to shore up or underpin the adjoining buildings have to be born by the excavator and his or her contractor if they intend to do so.  The expenses cannot be recovered from the adjoining owner.  This rule applies even though the excavator notifies the adjoining owner of his or her intention to excavate and the latter takes no measures to protect his or her buildings.  In such cases, the excavator can recover the expenses of protecting adjoining buildings, even though there was no controlling agreement or statute.