Article 856 of Civil Code

1 - Each owner may, at his own expense, make an alteration to the common parts if it would improve the use of those parts without changing their designated purpose or causing harm to the other owners. 2 - Before making the alteration, the approval of the general assembly of the association must be obtained in accordance with Article 867, and, where there is no association, the approval of a majority of three-quarters of the shares must be obtained. If he does not obtain approval, he may request the court to authorize him to make it.