The Glass Association of North America (GANA) is caught up on current glazing-related code activity thanks to a presentation by Tom Culp of Birch Point Consulting last week during GANA’s Fall Conference in Kansas City, Mo. Green building was a key topic—particularly what’s in store for the next edition of ASHRAE 189.1.
Culp said ASHRAE 189.1 and the International Green Construction Code (IgCC) are being combined. Moving forward, the green code’s technical content will be written by ASHRAE and the administrative content by the International Code Council. The two are also cooperating with other bodies such as the American Institute of Architects, the United States Green Building Council and the Illuminating Engineering society for consistency regarding LEED.
The 2017 edition of ASHRAE 189.1 is on pace to be finished in the fall of 2017, and it will form the basis for the 2018 IgCC.
According to Culp, proposed changes currently in progress include making the required U-factor and solar heat gain coefficient (SHGC) 5 percent lower than the base code, as well as an acoustic performance proposal that is still sitting in committee. The latter would include maximum background sound levels inside rooms, interior wall sound transmission, maximum reverberation times and maximum sound levels at the building’s property line.
“It does not specify STC or OITC requirements for windows, but a drive for quieter spaces could still push acoustic glazing,” said Culp.
There is also a new proposal to modify shading projection requirements, reducing the current 0.50 projection factor (PF) to 0.50 on only the first floor and 0.25 on higher floors. The proposal would change applicable zones from zones 1-5 to zones 0-3 to focus on warmer regions. “Some exceptions were also modified, but the exception allowing the use of dynamic glazing was retained,” said Culp.
Also, the ASHRAE workgroup focusing on indoor environmental quality moved two proposals forward to the main committee with stronger daylighting and new glare control requirements. Culp said requirements are being expanded from offices and classrooms to also include spaces such as libraries, healthcare, dining areas and concourses, and that the performance option in the proposal uses new daylight metrics: spatial daylight autonomy (sDA) and annual sunlight exposure (ASE). Meanwhile, glare control would require fenestration used for views to have operable blinds or dynamic glazing.
Culp said a third proposal with a new views requirement is still being revised. “It uses a similar concept as LEED but at reduced level, since it would be mandatory instead of an optional credit,” said Culp. The proposal requires 50 percent of the occupied floor space in “certain defined regularly occupied spaces” to have a view to the outside or an atrium. The view would need to be unobstructed up to a certain percentage and would include visible transmittance requirements.
“This would promote not just exterior glazing but also interior glazing in place of opaque partitions,” said Culp. However, he said this proposal “has less support than others,” and he’s not certain it will pass committee.
Finally, ASHRAE is developing a new standard that overlays 189.1—189.3—that addresses high performance healthcare facilities.