Changes to the purpose and scope that reflect advances in green buildings over the last 10 years are being proposed for ASHRAE/IES/USGBC/ICC Standard 189.1, Standard for the Design of High Performance Green Buildings. The standard contains minimum requirements for the siting, design, and construction of high-performance green buildings in support of reducing building energy use, resource consumption, and other environmental impacts while maintaining acceptable indoor environments.

Nine proposed addenda to the standard opened for public review on April 8, 2016. To comment or learn more, visit

Among them is addenda o, which proposes revisions to the existing purpose and scope of the standard to clarify its intended purposes and application, and to better reflect the revisions to the standard that are being considered by the committee.          

Committee chair Andrew Persily notes that the current title, purpose, and scope were approved in 2006 and that much has taken place in the world of green buildings in the past 10 years.

Under addenda o, the purpose of the standard has been rewritten to focus on goals vs. strategies. For example, rather than energy efficiency, the goal of reduced building emissions is proposed for inclusion in the purpose.

A new section of the purpose speaks to the alignment of Standard 189.1 with the International Green Construction Code (IgCC), noting specifically that the standard is intended to serve as the technical basis of mandatory buildings codes and regulations for high-performance buildings.     

Standard 189.1 currently is a compliance option of the 2015 IgCC, published by the International Code Council, ASTM, and the American Institute of Architects. The standard will serve as the technical content for the IgCC beginning in 2018.

Other addenda open for public review until May 8, 2016 include the following.

• Addendum i reorganizes the roof heat island mitigation section and adds new provisions for vegetated terrace and roofing systems relative to plant selection, growing medium, roof membrane protection, and clearances. In addition, provisions for the operation and maintenance of vegetated roofs are proposed for addition to Section 10.

• Addendum n clarifies footnote b to Table 7.5.2A. This footnote provides a method to adjust the percent reduction for buildings with unregulated energy costs exceeding 35% of the total energy cost. This addendum clarifies that the adjustment is to be made on the basis of energy cost, not energy use.

• Addendum p proposes to add requirements for water bottle filling stations, which are intended to improve water efficiency and sanitation of public drinking water and to reduce the environmental effects of plastic bottles.

• Addendum r lowers the ductwork pressure testing threshold to include 3-in pressure class ducts, which are common upstream of VAV boxes.

• Addendum t adds new requirements for reverse osmosis and onsite reclaimed water systems in order to reduce the likelihood of excessive water use due to poor design of water treatment and filter systems.

• Addendum u adds new requirements for water softeners to reduce water consumption given the impact of the design and efficiency of these systems on water discharge water rates.

The following is open for public review from until May 23.

• Addendum q modifies chapters 5, 7, 8, and 11 as well as Appendices A and E to reflect the addition of Climate Zone 0 in ANSI/ASHRAE Standard 169-2013, Climatic Data for Building Design Standards.

• Addendum s removes the performance option for water use and moves the prescriptive option into the mandatory section.