La. Stat. tit. 33 § 3723
Upon the passage of the ordinance the municipality shall be held to have taken a servitude of passage over all lands abutting the part or of the street to which the building line ordinance is applied, and the owners of these lands shall thereupon be entitled to all the benefits accruing to owners of lands or other property taken by the public for public use, under the laws of eminent domain. The ordinance shall also set a date, not later than twenty-five years after the passage of the ordinance, on which the municipality shall widen the street to the line established. Between the time of the passage of the ordinance and the time fixed for widening the street, the owners of the land over which the municipality has acquired the servitude may make any use of the land not inconsistent with the right of the municipality under its servitude, or inconsistent with the provisions of this Sub-part, including the right to maintain upon the land any building, structure, or appurtenances existing thereon at the time of the passage of the ordinance.
La. R.S. § 33:3723