(a) The State Building Inspector and the Codes and Standards Committee shall revise the State Building Code to require that commercial and residential buildings and building elements be designed to provide optimum cost-effective energy efficiency over the useful life of the building and to incorporate the 2012 International Energy Conservation Code, not later than eighteen months after the publication of said code. The provisions of this section shall not be construed to impose any new requirement for any renovation or construction of a state building that is subject to the requirements of § 16a-38k, regardless of whether such building has been granted an exemption under said section.

(b) Notwithstanding subsection (a) of this section, on and after July 1, 2010, the State Building Inspector and the Codes and Standards Committee, in consultation with the Commissioner of Administrative Services, shall revise the State Building Code to include provisions requiring certain buildings of or over a specified minimum size, that qualify as a new construction or a major alteration of a residential or nonresidential building, to meet or exceed optimum cost-effective building construction standards concerning the thermal envelope or mechanical systems, including, but not limited to, indoor air quality and water conservation, and the lighting and electrical systems of the building. Such provisions shall reference nationally accepted green building rating systems, including, but not limited to, the Leadership in Energy and Environmental Design rating system, the Green Globes USA design program, as established by the Green Building Initiative, the National Green Building Standard, as established by the National Association of Home Builders, or an equivalent rating system approved by the State Building Inspector and the Codes and Standards Committee. Such requirements shall include a method for demonstrating compliance at the time of application for a certificate of occupancy, including, but not limited to, private third-party certification or verification of compliance with the relevant portions of such rating systems, including, but not limited to, the energy and environmental portions.