Industry Says “Please Don’t Change;” Green Standard Writers Listen
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the U.S. Green Building Council and the Illuminating Engineering Society recently released the 2014 version of the American National Standards Institute (ANSI) green building standard, and one of the biggest aspects is what didn’t change: window-to-wall ratio.
“As reported last January, the proposal that would have reduced the glazing area allowed under the prescriptive path by 25 percent was defeated,” says Tom Culp of Birch Point Consulting. “This was a huge issue, and the entire industry joined together along with daylighting and other building science experts to show how the proposal was actually counter to high performance building design, daylighting, and occupant well-being. The committee agreed, and withdrew the proposal.”
There were, however, some changes in the new version, Standard 189.1-2014, “Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings,” which include implications regarding glass and fenestration.
“One change was in how they set the prescriptive envelope requirements, including windows,” says Culp. “Rather than develop the traditional tables of criteria for each zone and each product type, ASHRAE 189.1 now just sets its requirements as a set percentage better than ASHRAE 90.1.”
In the new standard, the U-factor is set for 10 percent lower than the ASHRAE 90.1 value in all zones, which Culp says will encourage more efficient products, but without requiring triple glazing.
For solar heat gain coefficient (SHGC), the standard considers how it ties into building orientation and daylighting. The SHGC is required to be 10 percent lower only on the west and east sides of the building, and not lower than 0.25.
This All-Glass House Shatters Assumptions
About ‘Green’ Construction
Forget that bit about throwing rocks. People who live in glass houses might be healthier and happier.
That’s the thinking behind the Photon Project a British start-up developing all-glass residences called Photon Spaces that the company says will “enhance the positive effects of natural light on health, well-being, mood and behavior.”
The idea for an all-glass dwelling arose from a chance meeting in 2010 between Charlie Sharman, the director of U.K. architectural glazing firm Cantifix, and Oxford University neuroscientist Russell Foster, an expert on how light affects sleep patterns and biological rhythms. An ongoing research project arose from those discussions.
“The biological facts about the relationship between daylight and health Russell told me about over a cup of coffee changed the way I thought about the world we live and work in,” Sharman said in a statement. “If it is true that light is the major stimulus for setting our body clocks, and when these clocks get out of sync with environmental time the impact on our health, mood and behavior can be extremely serious, then this must be an essential part of the conversation when designing buildings for human habitation.”
The 485-square-foot modular structures, which can be installed in about four weeks, will be made almost entirely of high-performance, energy-efficient glass that the company says blocks 63 percent of solar radiation, 99.9 percent of UV rays and 85 percent of external sounds. Windows can be darkened or lightened by a switch or a smartphone app thanks to advanced nano-scale particles suspended in a liquid and laminated between two pieces of glass.
The company says it can build the structures at a cost of $325,000 to $410,000.
The Photon Projectís initial target market will be luxury spas and hotels.
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