The greening of building codes is the next natural progression in the evolution of standards for building design, allowing us to weigh system solutions against their impact on the environment, while ensuring that buildings meet the needs of those who work or live in them.

As part of that progression, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the Illuminating Engineering Society (IES), and the U.S. Green Building Council (USGBC) have published the nation’s first code-intended standard for high-performance buildings. Standard 189.1, subtitled “Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings,” provides, according to ASHRAE, a “total building sustainability package” for those who strive to design, build, and operate green buildings. From site location to energy use to recycling, this standard seeks to set the foundation for green buildings through its adoption into local codes.

The major goals in publishing this standard were to provide simple compliance options for green buildings and to establish mandatory criteria in all topic areas: site sustainability, water use efficiency, energy efficiency, indoor environmental quality, and the building’s impact on the atmosphere, materials, and resources.

What makes Standard 189.1 different from existing voluntary green building rating programs? Existing programs, like USGBC’s LEED ratings, have become the fundamental catalyst for how we can design and construct buildings to be more sustainable. However, when striving to set the minimum mandatory requirements for green building projects, one finds that these systems contain few mandatory provisions that could be incorporated into green building codes. As an American National Standards Institute standard developed in model code language, Standard 189.1 sets minimum requirements for high-performance buildings and was designed to complement the other voluntary rating systems.

ASHRAE and its partners believe that “greening” the building codes, so to speak, is the logical step to improve building performance and minimize the impact of buildings on the environment. This standard follows in the footsteps of earlier game changers, Standard 90 and California’s Title 24, both of were released in 1975. Prior to that, the United States had no requirements regarding energy efficient buildings. As an industry, we can respond to the needs of communities around the world to reduce consumption of precious resources.

Outside influences are also moving toward an evolution in sustainable design. The Waxman-Markey Bill—a.k.a. the American Clean Energy and Security Act, ACES, H.R. 2454—requires new energy-efficiency standards for buildings and requires a 30 percent reduction in energy use by 2010 and 50 percent reduction by 2016, when compared with the current U.S. model energy code.

In addressing its own targets, Standard 189.1 includes mandatory provisions in each section with an option to utilize a prescriptive path or performance path for compliance. All projects must comply with the mandatory provisions. The prescriptive option contains additional criteria that provides a simple way to show compliance that involves little or no calculations. The performance option provides more design flexibility and is typically more complex than the prescriptive option.

Standard 189.1 provides another step in moving green building targets and regulations forward. For example, in the area of energy efficiency, Standard 189.1 is more stringent that Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings. The U.S. Department of Energy, through the National Renewable Energy Laboratory, made a preliminary energy savings estimate based on Standard 189.1, and estimated that applying the minimum set of prescriptive recommendations in Standard 189.1 would result in weighted average site energy savings of 30 percent when compared to Standard 90.1-2007.

Also important are the standard's mandatory provisions regarding indoor environmental quality. These requirements include improved source contaminant control; ventilation rates per ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality; elimination of air bypass around filters; no smoking; and outdoor air delivery monitoring. The standard also has requirements for acoustical control, daylighting by toplighting, and isolation of the building from pollutants in soil.

I encourage you to begin to understand the impact of these new requirements and identify the skills and knowledge you will need once the standard is implemented. As always, working toward sustainability isn’t something we do for ourselves, but for our children. Standard 189.1 will help to pave the way to a greener future.

Kent Peterson is chief engineer, P2S Engineering, Long Beach, Calif; chair of the ASHRAE/USGBC/IES Standard 189.1 committee; and served as ASHRAE’s 2007–2008 president.For more information on Standard 189.1, visit

Standard 189.1 Areas of Interest

Standard 189.1 addresses criteria divided into six areas of interest that typically are addressed by green building rating systems. Within each main topic area, the standard contains mandatory provisions and prescriptive- or performance-based compliance options addressing more specific elements of building performance. In complying with the standard, buildings should address the following areas and subsections.

SS: Sustainable Sites
1. Site Selection
2. Reduced heat island effect
3. Reduced light pollution

WE: Water Use Efficiency
1. Site water use, including possible use of bio-diverse plantings, hydrozoning, and smart irrigation controllers
2. Building water use, examining plumbing fixtures, appliances, and HVAC systems and equipment, as well as establishing cooling tower maximum cycles of concentration
3. Water measurement for buildings and subsystems

EE: Energy Efficiency
1. Increased energy efficiency over that required by Standard 90.1-2007
2. Renewable energy ready mandatory provisions
3. Energy measurement for verification
4. Electric peak load reduction
5. Renewable energy prescriptive requirement

IEQ: Indoor Environmental Quality
1. Indoor air quality
a. Ventilation rates per ASHRAE Standard 62.1
b. Outdoor air flow rate monitoring of minimum outside air
c. MERV 8 filter (MERV 13 in PM2.5 non-attainment areas)
d. No smoking inside building
e. Source contaminant control
2. Daylighting provisions
3. Acoustical control for exterior noise

MR: Building’s Impact on the Atmosphere, Materials & Resources
1. Construction waste management
2. Reduced impact materials
3. Provisions for use of wood products
4. No CFC Refrigerants
5. Storage and collection of recyclables and discarded goods

CO: Construction and Operations Plans
1. Acceptance testing/commissioning
2. IAQ construction management plan
3. Plans for operations regarding high-performance building operation, maintenance, service life, and transportation management