Subd. 1. Commissioner to adopt.

Not later than September 1, 1992, the commissioner of public service shall adopt amendments to the energy code portion of the Minnesota building code to implement energy-efficient standards for new commercial buildings.

Subd. 2. Adoption of ASHRAE/IES 90.1 standard.

The standards adopted under subdivision 1 must require energy efficiency at least as stringent as:

1. (1) the "minimum performance" standards for opaque building envelopes; and
2. (2) the January 1, 1992, standards for heating, ventilating and air conditioning, and water heating as proposed in ASHRAE/IES standard 90.1.

Subd. 3. Lighting standards.

The standards adopted under subdivision 1 must be at least as stringent as lighting standards for new federal buildings in Code of Federal Regulations, title 10, section 435.103.