Codes and Standards

What is Standard 189.1, and why does it matter?

ASHRAE Standard 189.1: International Green Construction Code is gaining industrywide consensus and momentum to become the all-in-one, go-to solution for code-enforceable green building design.
By Adam McMillen, PE, LEED AP BD+C, IMEG Corp., Naperville, Illinois June 18, 2019
Figure 2: A deeper dive into Section 6 of ASHRAE Standard 189.1: International Green Construction Code shows the breadth of topics, some of which are above and beyond U.S. Green Building Council LEED requirements. Courtesy: IMEG Corp.

Learning objectives


Learning to navigate green building codes, standards and guidelines is complex. Designing buildings that need to comply with a variety of codes and standards might include questions or comments like:  

  • Which version of ASHRAE 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings should we use? Or is it International Energy Conservation Code? 
  • Oh, yeah — we have to meet ASHRAE Standards 62.1 and 62.2: The Standards for Ventilation and Indoor Air Quality and ASHRAE Standard 55: Thermal Environmental Conditions for Human Occupancy and make sure the bicycle storage has clean air and no red list building materials. 
  • Should we use U.S. Green Building Council’s LEED v4 or try the new 4.1.? 
  • When does the new IECC come out? 
  • The city adopted the new version but made 10 pages of amendments. 
  • Wait — that review comment isn’t even in the reference guide! 

A code to unite them all 

ASHRAE Standard 189.1: International Green Construction Code is setting itself up to be an allinone, goto solution for strategic green building design.  

The standard was first published in 2009 through a partnership between USGBC, ASHRAE and Illuminating Engineering Society, with the most recent version published in 2017. It is intended to serve as the technical basis of mandatory building codes and regulations for high performance buildings.  

Unlike U.S. Green Building Council’s LEED and other voluntary standards, it is written as a codeenforceable document meant for adoption by international, national, state/province and local code jurisdictions. More broadly, it has been an effort to take many of the concepts brought to market by LEED and turn them into language that can be used as building code. Figure 1 provides a crossreference between ASHRAE Standard 189.1: International Green Construction Code and the LEED rating system. 

In 2014 the standard took a major step forward by aligning with the International Green Construction Code and USGBC’s LEED certification. Starting with the 2018 editionIgCC directly inserted the content of Standard 189.1-2017 as its base code languageA secondary goal aimed to align LEED and the standard in a way such that compliance with the standard means compliance with all LEED prerequisites.  

Figure 1: This shows a cross-reference of ASHRAE Standard 189.1: International Green Construction Code pages versus U.S. Green Building Council LEED points. Consider this as reference only, not direct a indication of stringency. Courtesy: IMEG Corp.

For a city that adopts IgCC that means more buildings may be willing to make the jump to full LEED certification since the prerequisite boxes are already checked. For projects that don’t make the jump, the city still knows its new buildings will meet the base requirements for being sustainable. More recently, the Standard 189.1 committee and USGBC have been cross-walking the nonprerequisite points in LEED to find even more areas of alignment. In many cases, Standard 189.1 exceeds requirements of LEED. At its best, this collaboration will result in the evolution of both efforts. As an example, see Figure 2 for a deeper dive into topics in Section 6 of the standard. 

Now in its fourth cycle of publication, Standard 189.1 has been developed through a consensusbased process among leading industry experts. With extensive crossover from other ASHRAE committees, it began with base from each of the ASHRAE standards and elevated them to the next level of green building design.  

For example, at the simplest level, lighting power densities in Standard 189.1 are lower than in ASHRAE 90.1; building pressure, venting and exhaust requirements supersede ASHRAE 62.1; and acoustic requirements are performance-based and extend scope for facilities not covered by ANSI/ASA 12.60 and FGI Guidelines 

The latest version, 2017, also includes things not found in other standards, like requirements for electric vehicle charging infrastructure, requirements for waterbottle filling, reclaimed waterready infrastructure, carbon emission requirements, automated demand response, acoustics requirements and life cycle assessment of materials/resources. To demonstrate the reach of the standard, see the newly added acoustic section in Figure 3 

To see what’s coming next for the base standards, take a peek at ASHRAE 189.1. When this process is working efficiently, new ideas are introduced in Standard 189.1, the industry responds and builds to meet economies of scale, they then meet costeffectiveness tests and roll into the base ASHRAE standards.  

Putting it into practice 

This is all good to know, but where is it going in practice? More than 20 cities and counties across 13 states have adopted Standard 189.1 in part or in whole. With the recent alignment to LEED in 2014 and additional streamlining of the standard, this number is expected to grow. The recent integration with the IgCC also should drive continued adoption nationally and internationally. Most importantly all this alignment means that ICC, ASHRAE, USGBC, AIA and IES all agree that if you want an above-base-code building code, this is the one to choose. 

Be proactive and prepareEngineers can either put off preparation and hope for the best or be proactive. Learn about the most impactful changes to come and develop the knowledge necessary to be successful. As design consultants are faced with ASHRAE 189.1’s growing emergence as the unified green building code, how do we best prepare? 

Meet the project requirements and design great buildingsFor projects within jurisdictions that have already adopted Standard 189.1 or the IgCCreading the standard document and user’s manual are the first steps. For projects where jurisdictions have not adopted Standard 189.1 but have adopted the latest available codes, Standard 189.1 is full of advanced strategies to find that extra 10% of energy savings or additional measures for other green infrastructure.  

For owners pursuing LEED, many measures in Standard 189.1 could qualify for LEED innovation points. Think of it as another sustainability expert in your firm. For owners looking to green their facility, Standard 189.1 provides a nice shopping list to find and implement favorite measures using enforceable language. 

Figure 2: A deeper dive into Section 6 of ASHRAE Standard 189.1: International Green Construction Code shows the breadth of topics, some of which are above and beyond U.S. Green Building Council LEED requirements. Courtesy: IMEG Corp.

Be seen as an expert in the field and show differentiators that help you win the next job. We’ve all been in a position where we wish we had that perfect idea or response during a client meeting — the one that says, “Yes we know where the industry is heading and here are three ways we plan to take you there. Or, “Yes, I know the city is adopting that new code next year — its not available yet but we expect these things to be coming down the road.  

Understanding Standard 189.1 — the edge standard for stretch codes and the future of the mainstream codes and standards — is the perfect way to have such answers at the ready. While we don’t always know when that new language will migrate over, it is extremely helpful to know what it means. Even if you don’t want to memorize every chapter, find a couple topics you are passionate about, become an expert in them, craft a strong, compelling story and get ready to impress the clients. 

Evolve your firm’s business over timeTo prepare the team for the continued sustainability evolutionincrease highperformance building literacy across the firm and remove barriers to implementing new design concepts. For specifying engineers, master details and master specifications can be a great place to include language about what is coming and how to easily wrap it into the design. While adding all the concepts within the standard is obviously out of the question, how about the top 10? Which 10? Perhaps those that are clean, cost-effective and differentiate your designs from the rest.  

Once you identify those 10, make them notes to specifier options in your master documents and point the team to resources to learn more. After you conquer the first 10 in 2019your reward is to move on to the next 10 in 2020 when the next version comes out. 

Do no harm (and maybe even a little good)Resource availability, human health and climate impacts are dominant themes of the 21st century. Highperformance buildings are a single solution to tackle all three of these issues. Finding ways to integrate innovative concepts from leading standards such as Standard 189.1 into projects will move us in a direction that can make people and future generations healthier and more productively engaged with the natural environment we all need to protect. Whether you see the value in one idea or 100, it’s important to find what connects you to this movement and act.  

As designers of buildings — one of the largest and most impactful of all human creations — our design decisions literally shape the future of the world’s human and environmental footprint. As leading players in the industry, let’s follow the same game plan and be successful in building a more sustainable world together.  

Figure 3: The 2017 edition of ASHRAE Standard 189.1: International Green Construction Code includes material not found in other standards, including a section on acoustics. Courtesy: ASHRAE, 2017 ASHRAE Standard 189.1

Five ways to benefit from ASHRAE 189.1  

  • Find innovative concepts that go above and beyond standard “green” practice. 
  • Nail that innovation question during the next interview. 
  • Find the design approach that differentiates your firm form the competition. 
  • Include Standard 189.1 concepts in master specification and details to improve literacy of your design engineers. 
  • Find your top passion and use it to improve your impact on the world. 

Adam McMillen, PE, LEED AP BD+C, IMEG Corp., Naperville, Illinois
Author Bio: Adam McMillen is director of sustainability at IMEG Corp. In addition to implementing technical design strategies that improve building performance, reduce energy use and preserve natural resources, McMillen builds industry relationships that positively impact the built environment.