Sustainable Buildings Standard to Define Green Buildings

A proposed new standard that will provide minimum guidelines for green building practices is nearing completion. Applicable to new commercial buildings and major renovation projects, it will address energy efficiency, a building’s impact on the atmosphere, sustainable sites, water-use efficiency, materials and resources, and indoor environmental quality.

Proposed Standard 189, Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings, is being developed by the Atlanta-based American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) in conjunction with the New York City-based Illuminating Engineering Society of North America (IESNA) and the Washington, D.C.-based U.S. Green Building Council (USGBC). This is the first such green building standard in the United States.

The proposed standard has been released for public review. Comments will be accepted through July 9, 2007. “Standard 189P will become the benchmark for all sustainable green buildings in the United States because it is being developed for inclusion into building codes,” says ASHRAE President Terry Townsend. “This means that owners and designers will have a consensus-based document that will set the minimum criteria that a building must satisfy in order to be considered a green building. The real impact of Standard 189P is that ASHRAE, along with IESNA and USGBC, are taking advanced energy conservation guidance mainstream for the general public's benefit.”

John Hogan, chair of the Standard 189 project committee, notes that the standard is not a building rating system, but rather a compilation of criteria that must be met in order for local building code officials to provide a Certificate of Occupancy for a facility.

Energy efficiency will be a large part of the standard. The goal is to achieve a minimum of 30-percent reduction in energy cost (and carbon-dioxide equivalent) over that in ANSI/ASHRAE/IESNA Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings, which provides minimum energy-efficiency design requirements for buildings except low-rise residential buildings and is the basis for building codes worldwide.

The standard shows leadership in renewable power generation on-site by having high-performance, green buildings avoid a total reliance on conventional energy sources. The committee that wrote the standard wants building projects to produce a minimum percentage of their peak electrical load through on-site generation such as by photovoltaic panels or equivalent solar water-heating systems.

Another important part of the proposed standard will be water-use efficiency. Hogan said the standard may require that interior water achieve a minimum of 25-percent reduction through improvements from the Energy Policy Act of 1992 for plumbing fixtures and strategies for reclaiming water in other areas. Exterior water systems would have more sophisticated controls and not use potable water, he says. Hogan said one topic of interest to the committee is sustainable sites. Members are discussing requiring construction to take place on appropriate sites where construction already exists or on a “greenfield” site that is close to high-density areas or has access to mass transit. 

In the area of indoor environmental quality, the committee is considering requiring that supply outdoor air exceed the minimum requirements of ASHRAE 62.1-2007, Ventilation for Acceptable Indoor Air Quality. Also being discussed are the use of low-emitting materials and installation of CO₂ sensors to monitor densely-occupied spaces.

The committee is also looking at requirements for a construction plan, a transportation management plan, and an indoor air quality (IAQ) management plan, according to Hogan, to reduce materials and energy consumption as well as to reduce carbon emissions.

Proposed Standard 189P will be available only during public review periods. To read the addenda or to comment, visit (www.ashrae.org/publicreviews).

This information was provided by ASHRAE, an international organization of some 50,000 persons. ASHRAE fulfills its mission of advancing heating, ventilation, air-conditioning, and refrigeration to serve humanity and promote a sustainable world through research, standards writing, publishing, and continuing education. For more information, visit (www.ashrae.org).