The Mayor of the District of Columbia, whenever he deems it desirable in the interest of economy, may permit buildings existing at the time said building lines are established and which project beyond said lines to remain until such time as the owner of said buildings desires to reconstruct or substantially alter the said buildings; provided, that § 6-404 shall apply to all parkings established under this chapter, and the control of said parkings otherwise shall be vested in the Mayor of the District of Columbia, and the Council of the District of Columbia is hereby authorized to make, and the Mayor is hereby authorized to enforce, all reasonable and necessary regulations for their care and preservation.
D.C. Code § 6-405