(a) For the purposes of Sections 20 and 25, this Act applies to newly constructed single-family homes and multifamily residential buildings that have parking spaces and are constructed after the effective date of this Act.
     (b) For the purposes of Sections 30 and 35, this Act applies to unit owners, tenants, landlords, and associations of both newly constructed and existing single-family homes and multifamily residential buildings that have parking spaces.