Article 658. The easement of party wall shall be governed by the provisions of this Title, by the local ordinances and customs insofar as they do not conflict with the same, and by the rules of co-ownership. (571a)
Article 659. The existence of an easement of party wall is presumed, unless there is a title, or exterior sign, or proof to the contrary:
(1) In dividing walls of adjoining buildings up to the point of common elevation;
(2) In dividing walls of gardens or yards situated in cities, towns, or in rural communities;
(3) In fences, walls and live hedges dividing rural lands. (572)
Article 660. It is understood that there is an exterior sign, contrary to the easement of party wall:
(1) Whenever in the dividing wall of buildings there is a window or opening;
(2) Whenever the dividing wall is, on one side, straight and plumb on all its facement, and on the other, it has similar conditions on the upper part, but the lower part slants or projects outward;
(3) Whenever the entire wall is built within the boundaries of one of the estates;
(4) Whenever the dividing wall bears the burden of the binding beams, floors and roof frame of one of the buildings, but not those of the others;
(5) Whenever the dividing wall between courtyards, gardens, and tenements is constructed in such a way that the coping sheds the water upon only one of the estates;
(6) Whenever the dividing wall, being built of masonry, has stepping stones, which at certain intervals project from the surface on one side only, but not on the other;
(7) Whenever lands inclosed by fences or live hedges adjoin others which are not inclosed.
In all these cases, the ownership of the walls, fences or hedges shall be deemed to belong exclusively to the owner of the property or tenement which has in its favor the presumption based on any one of these signs. (573)
Article 661. Ditches or drains opened between two estates are also presumed as common to both, if there is no title or sign showing the contrary.
There is a sign contrary to the part-ownership whenever the earth or dirt removed to open the ditch or to clean it is only on one side thereof, in which case the ownership of the ditch shall belong exclusively to the owner of the land having this exterior sign in its favor. (574)
Article 662. The cost of repairs and construction of party walls and the maintenance of fences, live hedges, ditches, and drains owned in common, shall be borne by all the owners of the lands or tenements having the party wall in their favor, in proportion to the right of each.
Nevertheless, any owner may exempt himself from contributing to this charge by renouncing his part-ownership, except when the party wall supports a building belonging to him. (575)
Article 663. If the owner of a building, supported by a party wall desires to demolish the building, he may also renounce his part-ownership of the wall, but the cost of all repairs and work necessary to prevent any damage which the demolition may cause to the party wall, on this occasion only, shall be borne by him. (576)
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)
Article 665. The other owners who have not contributed in giving increased height, depth or thickness to the wall may, nevertheless, acquire the right of part-ownership therein, by paying proportionally the value of the work at the time of the acquisition and of the land used for its increased thickness. (578a)
Article 666. Every part-owner of a party wall may use it in proportion to the right he may have in the co-ownership, without interfering with the common and respective uses by the other co-owners. (579a)