Article 664

Every owner may increase the height of the party wall, doing so at his own expense and paying for any damage which may be caused by the work, even though such damage be temporary.

The expenses of maintaining the wall in the part newly raised or deepened at its foundation shall also be paid for by him; and, in addition, the indemnity for the increased expenses which may be necessary for the preservation of the party wall by reason of the greater height or depth which has been given it.

If the party wall cannot bear the increased height, the owner desiring to raise it shall be obliged to reconstruct it at his own expense and, if for this purpose it be necessary to make it thicker, he shall give the space required from his own land. (577)