Rent shall not be recoverable by the owner or lessee of any dwelling unit which does not comply with the provisions of this chapter for any period of occupancy which commences on or after the date that the City gives notice to the owner and tenant of the provisions of this section. Rent shall not thereupon be recoverable by the owner of such dwelling unit until the City gives written notice to the owner and occupant that such dwelling unit has been issued a valid inspection certificate as required by this chapter.