We are assisting a design-build team in Japan with getting their project to be LEED Silver certified. To meet this prerequisite, is it absolutely required to follow ASHRAE 90.1-2007? The project falls within Climate Zone 1, and according to Table 5.5-1 Building Envelope Requirements, the vertical glazing has a SHGC max of 0.25. This level of SHGC is very aggressive for their product availability in Japan. The only glazing that they could find that meets this SHGC has a high reflectance which the Client is against as the function of the facility is a child care facility where they want to have good visibility in and out. Please advise if there is another way around the ASHRAE 90.1-2007 requirement.
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
February 24, 2011 - 1:25 pm
Projects must follow 90.1, however, it does not typically require you to meet every prescriptive requirement. The SHGC is not a mandatory provision so it is available for tradeoff as are all building envelope provisions in the climate zone tables. Assuming that you are demonstrating prerequisite compliance with your energy model for EAc1 following Appendix G, you do not need to meet this prescriptive requirement of 90.1.
Ivy Chen
ManagerBanyan Tree Hotels & Resorts
December 4, 2012 - 5:07 am
Hi, How abt in baseline energy modeling, do we have to follow strictly Table5.5? My project falls in Climate Zone 1.The vertical glazing SHGC value of 0.25 in Table 5.5 seems very aggressive which results in energy consumption of proposed design is higher than baseline.
In addition, the U value of Roofs and Walls decribed in Table 5.5 are pretty low, which can hardly be met from standard building details commonly adopted in tropical countries.
In short, the baseline set in ASHRAE seems quite high standard.
Could you please advise? We are trying to get our LEED certification for our vietnam project but then realize we might fail after we started working on the energy modeling.
Thank you very much.
from someone almost desparate
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
December 4, 2012 - 9:18 am
The baseline must be modeled according to Appendix G which references Table 5.5 so you must model the baseline that way.
Not sure about Vietnam but SHGC 0.25 glazing is easily available here.
As mentioned above you do not have to meet the prescriptive insulation requirements and can get your savings in the other building systems. Are you certain that the insulation is causing the problem? Did you run some different insulation iterations to see the effect?
Sounds to me like you need to identify the major energy using systems and strategies for reducing the energy use associated with them. The intent is to design an energy efficient building, so instead of seeking exceptions to baseline requirements figure out how to make the building use less energy.