The International Energy Conservation Code (IECC), issued by the International Code Council, is a modern, up-to-date energy conservation code addressing the design of energy-efficient building envelopes and installation of energy efficient mechanical, lighting and power systems through requirements emphasizing performance. The Director shall adopt regulations for the conservation of energy in buildings that must include the adoption of the most recent version of the IECC and any amendments to the IECC that will not materially lessen the effective energy savings requirements of the IECC and are deemed necessary to support effective compliance and enforcement of the IECC.