All land, buildings, structures or appurtenances thereon located within the City of Winnsboro, Texas, which are hereafter occupied, used, erected, altered, removed, repaired, replaced, demolished or converted shall be occupied, used, erected, altered, removed, placed, demolished or converted in conformance with the zoning regulations prescribed for the zoning district in which such land or building is located as hereinafter provided and all nonconforming uses in use at time of passage of this amendment shall be considered approved nonconforming uses.