New Jersey Statutes Title 46. Property 46 § 10-1

Whenever excavations, for buildings or other purposes, on any lot or piece of land, shall be intended to be carried to a depth of more than eight feet below the curb or grade of the street, and there shall be any party or other wall, wholly or partly on adjoining land, and standing upon or near the boundary lines of such lot or piece of land, the person causing such excavations to be made, if afforded the necessary license to enter on the adjoining land, but not otherwise, shall, at all times, from the commencement until the completion of such excavations, preserve, at his own expense, such party or other wall from injury, and so support the same by a proper foundation that it shall remain as stable as before such excavations were commenced.