For the purpose of applying the Acts to designated smoking areas permitted because the employer is exempt under D.C. Official Code §7-743 or has obtained an economic hardship waiver under D.C. Official Code §7-745, all buildings constructed before August 3, 1991, shall be deemed to be in compliance with the ventilation requirements of the District of Columbia Construction Codes, unless the building has undergone a renovation since August 3, 1991, that required a building permit.
D.C. Mun. Regs. tit. 20, r. 20-2102