Construction and operation prohibited. No owner or operator of a proposed major facility, NSR major modification, or existing major facility which undertakes a significant modification but avoids NSR applicability through netting, shall be allowed to begin actual construction, commence operation, or operate such new facility or modification, as appropriate, without a permit which incorporates the requirements of this Part. This provision shall not affect any requirement under Part 201 of this Title for an owner and/or operator to obtain a permit or permit modification prior to beginning actual construction, commencing operation or operating a new or modified facility.