New version of Green Standard Now Available from ASHRAE, USGBC, IES

ATLANTA, Ga.— Changes to help make buildings and systems more sustainable are part of the newly published version of the high-performance green building standard from ASHRAE, the U.S. Green Building Council and the Illuminating Engineering Society

ANSI/ASHRAE/USGBC/IES Standard 189.1-2011, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, provides a green-building foundation for those who strive to design, build and operate high-performance buildings. It covers key topic areas of site sustainability, water-use efficiency, energy efficiency, indoor environmental quality and the building's impact on the atmosphere, materials and resources. When first introduced in 2009, the standard was the first code-intended commercial green-building standard in the United States.

The most significant change in energy-related provisions results from new requirements in ANSI/ASHRAE/IES Standard 90.1-2010, Energy Standard for Buildings Except Low-Rise Residential Buildings, adding to and superseding requirements in the 2007 version. In October 2011, the U.S. Department of Energy found that the 2010 version of Standard 90.1 contains significant energy savings over the 2007 standard. The energy savings in the Standard 90.1-2010 provisions also result in energy savings for building projects complying with Standard 189.1.

In addition, mandatory and prescriptive renewable energy requirements were clarified to reduce confusion and simplify calculations; now both mandatory provisions to prepare for onsite renewable energy and provisions to produce prescribed levels of renewable energy must be met. Additionally, buildings that meet the prescriptive requirement for renewable energy production are now deemed to comply with the mandatory requirement for renewable energy site-preparation.

Additional changes to the 2011 standard include :

> More stringent Lighting Power Density allowances due to the change in reference to Standard 90.1-2010. Both interior and exterior values are now set as a percentage of the Standard 90.1 allowances, based on building, space or area type.
> Automatic controls are now required for lighted signs visible during daytime hours; controls must reduce the lighting power to 35 percent of full power. For other outdoor signs, automatic controls must now turn off lighting during daytime hours and reduce the lighting power to 70 percent of full power after midnight.
> Open-graded (uniformed size) aggregate and porous pavers (e.g., open-grid pavers) qualify as a hardscape surface for heat-island mitigation with no further testing. Permeable pavement and permeable pavers must meet a minimum percolation rate rather than a minimum solar reflectance index.

Standard 189.1 is a jurisdictional compliance option in the International Green Construction Code developed by the International Code Council, ASTM International and the American Institute of Architects. For details, visit www.ashrae.org/bookstore.