ANSI/ASHRAE/IES Standard 90.1-2010 Requirements

[nitramnaed]

My state just recently adopted the the forth titled standard as the states energy code. I have a mass wall building. 12" Concrete block walls with 2" cavity insulation, airspace and brick veneer. It also has a pre-cast concrete roof.

My question is, I don't see anything in the code that requires the insulation to be continuous up the wall over the parapet and connecting to the required roof insulation.

I know the mandatory requirements say continuous air barrier must connect.

If there isn't a requirement, the thermal bridging at the parapet kind of defeats the whole purpose.

Am I missing something?

Additionally it doesn't seem consistent that the two prescriptive methods are different with one allowing a U assembly calculation with no requirement for ci and a R value calc that does require ci.

Thanks, Jeff

:culpability:

 

[north star]

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nitramnaed,

In looking at Ch. 3 - Definitions, [ in my `07, Standard 90.1 ]

...are you sure that your parapet wall meets the definition

of being part of the building envelope ?.............Also, ...will your

"above grade parapet wall" have any roofing material affixed

to it, or will it be bare concrete rated for weather exposure,

or something else ?

Thanks !

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[nitramnaed]

I have attached a detail that is similar to what I'm describing.

View attachment 2182

View attachment 2182

/monthly_2016_02/572953f51364f_ScreenShot2016-02-24at3.42.02PM.png.3f8366792b4c1f8b88a3e635e4c2d752.png

 

[north star]

@ @ >

"I know the mandatory requirements say continuous air barrier must connect.If there isn't a requirement, the thermal bridging at the parapet kind of

defeats the whole purpose. Am I missing something? "

In looking at my copy of the `07, ASHRAE 90.1 Standard, Ch. 3 - Definitions,Abbreviations and Acronyms: At the definition of the building envelope, and

looking at the drawing that you provided, ...IMO, where the conditioned

space intersects with the lower portion of the parapet wall, ...you do not have

an element that will transfer thermal energy, either from outside in, or from

inside out.

If you believe that that intersection will indeed transfer thermal energy in or

out, then "Yes, ...you would need to extend compliant amounts of thermal

insulation up over the parapet wall.

There may be some language in the 2010 Edition of the 90.1 Standard that

is more clear on this subject, but I could not locate it.........Sorry !

My opinion says "No, ...you do not have to insulate up and over the top of

the parapet wall, but I am not the Energy Nazis, or the AHJ.

I am enclosing a link to a DOE, Comparison of the 2010, ASHRAE 90.1

Standard with the 2012 IECC Standard........Enjoy !

https://www.iccsafe.org/gr/Documents/IECC-Toolkit/2012IECC_ASHRAE%2090%201-10ComparisonTable.pdf

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