 The provision was held to apply only to certificates of occupancy that preceded the residential use of the unit.In "Burien, LCC v. James A. Wiley" the Landlord contended that this Costa–Hawkins exemption applies to buildings converted from apartments to condominiums (both residential uses), when a new certificate is issued for the latter.The court reasoned that the purpose of the statute's exemption is to promote construction and development that increase the supply of rental housing, not to promote token reclassification without such a result.