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U-Values on windows.??!!?

R

righter101

Gold Member
Joined
Dec 5, 2009
Messages
604
Hello there. Great State of Washington here.

New State energy code requires either 0.34, 0.32, or 0.30 U values for all glazing, depending on the glazing as a % of floor area. (up to 13%, 25%, and Unlimited, respectively.)

Prior to the change, it was 0.35 for all glazing, unlimited. That was the standard everyone got used to.

They fill out the forms, sign the energy code compliance forms, it's noted on the plans and inspection card.

House gets built. Windows get ordered. Come inspection time, they have windows that are 0.34 and 0.35. Above the minimum. Code violation, technically.

Would you make them replace the glazing?

Would you make a modificaiton based on (???)?

My job is to enforce the codes, but also to make modifications when practical.

Is it unreasonable to consider the "energy" required to make new glazing and the expense/energy used to put the replacement glazing in? It would be hard to quantify that in terms, relative to the miniscule savings of .32 windows vs. .34.

Just looking for opinions. I have mine (and my biases as well, and it may show in my post.)

Thanks for input and feedback.
 
Does Wash have an alternative to a prescriptive path? Ask them to provide another analysis if possible

In other words make them work to correct THEIR mistake

In the future simplify the process and have them submitt 0.30 windows only. That's what MT did so that is all the window suppliers carry.
 
mtlogcabin said:
Does Wash have an alternative to a prescriptive path? Ask them to provide another analysis if possibleIn other words make them work to correct THEIR mistake

In the future simplify the process and have them submitt 0.30 windows only. That's what MT did so that is all the window suppliers carry.
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We do have a "component analysis" that makes up for deficiencies in one area etc...

They don't comply that path either. It's over by a tiny amount, not much.

Just wondering how liberal you are with modifications on issues such as this.

I liked our previous EC that had a single value. I hope it goes back to that.
 
ResCheck is a software based alternative approach. Curious as querry is unclear, were the plans approved before or after the effective date of the change? If your ECCC is based on the 2009 IECCC, then there should be alternatives to the prescriptive path.
 
JBI said:
ResCheck is a software based alternative approach. Curious as querry is unclear, were the plans approved before or after the effective date of the change? If your ECCC is based on the 2009 IECCC, then there should be alternatives to the prescriptive path.
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They applied under the current code, 2009 Washington State Energy Code. The applicant signed forms saying they would comply with "Option 3" which, among other things, required 0.30 glazing.

They contractor installed windows that are .34 and .35.

The alternative to a prescriptive path is a component analysis. They have tried that and they don't comply.

They actually fit under "prescriptive option 2" which would allow .32 windows (since they have less than 25% glazing as a % of floor area).

Basically, the fix is replace all the glazing with .32 value glass or get a modification.

I find the trivial savings in energy negligible compared with the cost, expense, waste of windows, and energy used in transportation and manufacturing.

I am just trying to get a gauge or feel from others how they feel about energy code issues such as this. What good is served by having them change the windows out? A touch of energy savings? How much really?

Could we consider installation of cellular shades as an equivalent for modification??

I don't like to make people do things just because I can. I like it to have a practical benefit.

One of the ironies I find in the energy codes, or at least ours, is that it allows a weighted average to be used for glazing U values. Seems reasonable. You have some at .34 and some at .30. See if it meets the .32 value.. Fair enough.

Lets say someone is just a bit over.

In theory, they could cut a huge hole in a wall, remove all of the nice R21 insulation and put in a HUGE piece of glass that is, let's say, 90 square feet but has a U value of .28. This would put them under the "weighted average". Is this house "better" insulated than before they did it?

When I find a situation where someone could do a bunch of goofy stuff to get to the letter of the code, I have to step back and ask, is this reasonable?

Also, our energy code glazing % is based on glazing as a % of floor area. A 2000 square foot house with an 8 foot ceiling is treated the same as a 2000 house with 16 foot ceilings.

Just wondering what others thought.

I already have my opinion but I wanted to hear from those on both sides of the issue. Those who feel strongly about the energy code and those who are perhaps more flexible.
 
Approve it and move on. Could add some additional insulation in the attic to help balance the window oversight. At least if someone questions the windows you have something to point to as beyond what was required.
 
"Deleted"

My mom always said if you have nothing nice to say then keep your trap shut.

One nice thing is: Our County Deleted 101.4 chapter 4 and chapter 5 of the IECC
 
righter101 said:
We do have a "component analysis" that makes up for deficiencies in one area etc...They don't comply that path either. It's over by a tiny amount, not much.

Just wondering how liberal you are with modifications on issues such as this.

I liked our previous EC that had a single value. I hope it goes back to that.
Click to expand...
If they are over by only a tiny amount have them add something elsewhere. More blown-in insulation or better door. Have them quickly look at the entire structure and propose something/anything as an energy trade-off, but make them propose it. I would be liberal in carrying out the intent of the energy code. They could hire an engineer to perform a systems analysis and likely demonstrate compliance, but hardly worth it.

I doubt that the WSEC will get simpler. They are talking about amending and adopting the IECC. Holy cow! Super Good Cents my a**.
 
righter101 said:
They applied under the current code, 2009 Washington State Energy Code. The applicant signed forms saying they would comply with "Option 3" which, among other things, required 0.30 glazing.They contractor installed windows that are .34 and .35.

The alternative to a prescriptive path is a component analysis. They have tried that and they don't comply.

They actually fit under "prescriptive option 2" which would allow .32 windows (since they have less than 25% glazing as a % of floor area).

Basically, the fix is replace all the glazing with .32 value glass or get a modification.

I find the trivial savings in energy negligible compared with the cost, expense, waste of windows, and energy used in transportation and manufacturing.

I am just trying to get a gauge or feel from others how they feel about energy code issues such as this. What good is served by having them change the windows out? A touch of energy savings? How much really?

Could we consider installation of cellular shades as an equivalent for modification??

I don't like to make people do things just because I can. I like it to have a practical benefit.

One of the ironies I find in the energy codes, or at least ours, is that it allows a weighted average to be used for glazing U values. Seems reasonable. You have some at .34 and some at .30. See if it meets the .32 value.. Fair enough.

Lets say someone is just a bit over.

In theory, they could cut a huge hole in a wall, remove all of the nice R21 insulation and put in a HUGE piece of glass that is, let's say, 90 square feet but has a U value of .28. This would put them under the "weighted average". Is this house "better" insulated than before they did it?

When I find a situation where someone could do a bunch of goofy stuff to get to the letter of the code, I have to step back and ask, is this reasonable?

Also, our energy code glazing % is based on glazing as a % of floor area. A 2000 square foot house with an 8 foot ceiling is treated the same as a 2000 house with 16 foot ceilings.

Just wondering what others thought.

I already have my opinion but I wanted to hear from those on both sides of the issue. Those who feel strongly about the energy code and those who are perhaps more flexible.
Click to expand...
Had an unheated warehouse that was a fast track project. Changed use to a fleet maintenance garage that maintained and repaired garbage trucks. Big doors moving vehicles in and out all day long. We installed radiant heaters over a handful of bays to take the nip off the air for the mechanics. AHJ determined that they would require it to comply with current codes for new construction since we moved from unheated to fully heated. We also cut in a daylight panel (translucent fiberglass) around the entire perimeter of the structure. With a systems analysis we demonstrated compliance. Talk about a tailspin and mountain of paperwork.
 
As many others have suggested, have them propose a trade-off, document the proposal, approve it with a notification that the proposed trade-off will not be permitted on future projects and move on down the road.

Good questions and answers. I wish there were more common sense threads on the Energy Code like this one.

Imhotep...I like your solution on the Warehouse. Wish we had more ziggurat architects like yourself around here.
 
KZQuixote said:
Could they reglaze some of the windows with more efficient glass to reach an average that's acceptable?Bill
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Yes. Cost in terms of labor and money would be high in my opinion. They have told me it is $3K in materials plus the trip here (by boat) and the day by the crew.

They will do that if it is absolutely required.

I am contemplating a modification because it seems silly to me.
 
This is a panelized home built by a company that does panelized construction. They built it for a specific project owner.
 
righter101 said:
This is a panelized home built by a company that does panelized construction. They built it for a specific project owner.
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If you mean a SIPS panel then I would not have worried about it.

The problem I see now is you have brought up non-code compliant items and you need some kind of documentation in your file to back up your approval (cost is not a factor)
 
mtlogcabin said:
If you mean a SIPS panel then I would not have worried about it.The problem I see now is you have brought up non-code compliant items and you need some kind of documentation in your file to back up your approval (cost is not a factor)
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It is not SIPS.

They are standard stick frame construction, but built off site, shipped in 6 or 8 large pieces, then assembled.

Why is cost not a factor?
 
The codes do not recoginize cost as an excuse to not fix a violation once it has been documented.
 
gbhammer said:
The codes do not recoginize cost as an excuse to not fix a violation once it has been documented.
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I would agree, somewhat with your statement.

Note that R101.3 of the IRC, the "INTENT" does mention affordibility.
 
righter101 said:
I would agree, somewhat with your statement.Note that R101.3 of the IRC, the "INTENT" does mention affordibility.
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Never noticed that before, thanks.

Question is why would they lie like that?
 
They could do an equivalency evaluation

(A_ir/R_ir) ≥ (A_ip/R_ip)

Where;

R_ir = RSI value required by 9.36.2.6"

A_ir= Area of the referenced assembly"

R_ip= Proposed RSI value"

A_ip = Area of the referenced assembly"
 
righter101 said:
I would agree, somewhat with your statement.Note that R101.3 of the IRC, the "INTENT" does mention affordibility.
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I suppose the ICC "believes" that if the codes are followed as written then the construction of a one/two family dwelling will be affordable.

A violation would not fall under the affordable statement.
 
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