A much-anticipated green-building standard being developed by ASHRAE and two other industry organizations includes provisions seen as likely to significantly expand the use of cool roofs, cool-roof coatings, and air-barrier technologies.
In addition, the measure—a “code-intended” standard that would serve as a model for local and regional building codes—includes indoor air-quality guidelines that call for the use of very low-VOC paint, coatings, and other building materials.
ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) recently initiated a new round of public review for Proposed Standard 189.1, Standard for the Design of High Performance, Green Buildings Except Low-Rise Residential Buildings. The proposed standard would be the “first code-intended commercial green-building standard in the United States,” with publication anticipated in early 2010, ASHRAE said. The standard is being developed by ASHRAE in conjunction with the Illuminating Engineering Society (IES) and the U.S. Green Building Council (USGBC).
“This is one of the most highly-anticipated building standards ever released,” said ASHRAE President Gordon Holness.
“ASHRAE’s commitment to excellence and transparency in true consensus standards development is reflected in the quality of and interest in Standard 189.1.”
The newly announced public-review period—the fourth for the standard—is an “independent substantive change” review, meaning that only changes from the third public review, which ended in June, are open for comment. The public comment period started Sept. 18 and remains open until Nov. 2.
A copy of the public-review draft can be viewed at www.ashrae.org/publicreviews. Copies of public-review drafts are only available during public-review periods.
The draft standard, which has undergone substantial revision since development of the document began more than three years ago, is likely to translate into local building codes that emphasize the use of cool roofs, cool-roof coatings, and air barriers, while also leading to indoor air-quality guidelines affecting the selection and use of paints, coatings, and other materials.
Sections of the draft standard that hold implications for these technologies include the following.
For buildings and covered-parking roof surfaces in climate zones 1,2, and 3—the southern regions of the U.S.—75% of the roof surface must be covered with materials with a minimum initial solar-reflective index (SRI) of 78 (for low-slope roofs) and a minimum initial SRI of 29 (for steep-slope roofs). As an alternative, these roof surfaces can comply with the U.S. EPA’s Energy Star® eligibility requirements for roof products. Climate zone 4 had been included in the previous draft of the proposed standard, but was dropped in the latest draft.
The 75% roof-surface requirement excludes areas used for roof penetrations and associated equipment, solar thermal energy collectors, portions of the roof used to capture heat for building-energy technologies, rooftop decks or walkways, or green roofing systems.
The proposed standard states that the building envelope must be designed and built with a continuous air barrier that complies with the provisions of the standard’s Appendix B, in buildings with conditioned space. The air-barrier components must be clearly identified on construction documents, with details on joints, interconnections, and penetrations.
Exceptions are made for building envelopes of semiheated spaces, provided the building envelope complies with Section 22.214.171.124 of ASHRAE/IESNA Standard 90.1.
Appendix B spells out the specific requirements of the air barrier, stating that it must be continuous throughout the wall and ceiling or roof, completely sealed, flexible to allow movement of assemblies and components, and capable of withstanding wind, stack, and fan pressures.
Also spelled out are air-permeance requirements of air-barrier materials and assemblies.
Section 8.4.2. of the draft includes new provisions on materials that affect indoor air quality, including paint, coatings, adhesives, sealants, and other products.
For section 126.96.36.199 on paints and coatings, products covered include sealers, stains, clear wood finishes, floor sealers and coatings, waterproofing sealers, primers, flat paints and coatings, nonflat paints and coatings, and rust-preventative coatings. Air-quality requirements in the draft apply to paints and coatings used on the interior of the building, defined as inside the weatherproofing system and applied on-site.
Under the emissions requirements, defined in Section 188.8.131.52.1, emissions are determined according to CA /DHS/EHLB/R-174, commonly referred to as California Section 01350, and must comply with the limit requirements for either office or classroom spaces, regardless of the space type. The VOC content requirements, defined in Section 184.108.40.206.2, stipulate that products comply with Green Seal Standard GS-11 (for architectural paints, coatings, and primers applied to interior surfaces), or with South Coast Air Quality Management District (SCAQMD) Rule 1113 (for clear wood finishes, floor coatings, stains, sealers, and shellacs).
The draft standard has been extensively revised since the committee developing the document was expanded and “essentially reconstituted” about a year ago, said Kent Peterson, who took over as chairman of the panel—Standard Project Committee for 189.1—at that time.
Peterson, a past president of ASHRAE, discussed specific provisions of the draft standard in a phone interview with PaintSquare.
“The objective was to get better representation, with more groups participating in the development and consensus process,” said Peterson, vice president and chief engineer of P2S Engineering Inc., Long Beach, CA. He said the building-owner community “had not been well represented” earlier on in the standard-development process, and building-code officials were also brought to the table to assist in the process of crafting “code-intended language” in the document. Representation of affected industries, particularly the utility industry, was also augmented, he said.
Peterson said minor revisions are anticipated in the current, fourth public review of the draft standard, with approval believed likely before the end of the year. Publication requires assent by the ASHRAE board of directors and the leadership of USGBC and IESNA. He said some building-code authorities have already begun developing new codes based on the earlier drafts of the standard, in anticipation of its publication.