(a) Hardship. Where the Commissioner of Planning and Natural Resources finds that extraordinary hardships may result from strict compliance with this subchapter, or regulations adopted pursuant thereto, it may vary the terms of this subchapter so that substantial justice may be done and the public interest secured: Provided, That such variation will not have the effect of nullifying the intent and purpose of this subchapter.
(b) Large scale development. Standards and requirements of this subchapter or regulations adopted pursuant thereto may be modified by the Historic Preservation Commission in the case of a plan and program for a comprehensive new development or neighborhood which in the judgment of the Historic Preservation Commission provides adequate public spaces and improvements for the circulation, recreation, light, air, and service needs of the tract when fully developed and populated, and which also provides such covenants or other legal provisions as will assure conformity to and achievement of the plan.
(c) Conditions. In granting variances and modifications, the Commissioner of Planning and Natural Resources may require such conditions as will in its judgment secure substantially the objectives of the standards or requirements so varied or modified.
(d) Notwithstanding any other provision of law, no variance or modification granted by the Historic Preservation Commission, which would permit an increase in the height of any structure by more than two stories or 30 feet above the maximum height permitted without such variance or modification, shall be effective until approved by the Governor and the Legislature.