ASHRAE R-value Increase - Opinions?

[Dan Steinbok]

ASHRAE increases roof and wall R-value for first time in 19 years
http://www.bdcnetwork.com/article/CA....html?q=ashrae
http://www.ashrae.org/pressroom/detail/16616

January 22, 2008

For the first time in over 19 years, ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) recently announced an increase to the minimum required prescriptive R-value (resistance to heat flow) for roof and wall insulation levels in Standard 90.1

The above-deck roof insulation requirements currently at R-15 go to R-20 – an increase of 33% – in every climate zone in the U.S. Similar increases were approved for walls.

"ASHRAE is to be commended for establishing a new benchmark for building energy efficiency," said Jared Blum, President of PIMA. "According to the Department of Energy commercial buildings and homes account for 40% of the energy consumed in the United States. The increased values establish a new national standard minimum against which all codes can be compared and pave the way for buildings with improved efficiency and decreased carbon footprint."

The increased roof and wall insulation values apply to all commercial and high- rise residential buildings covered by Standard 90.1. These changes now become a part of the newest edition of the Standard 90.1-2007.

"Architects across the country are already installing insulation at levels that exceed these values. Those architects and designers seeking beyond-code recognitions (such as LEED, Energy Star, Building America, etc.) will now go even further to deliver advanced building envelopes with higher levels of insulation," added Blum.

What is everyone's take on the increased R-Value requirements?

Do you think the efficiency improvement (on order of perhaps 5%) will balance with the increased stud-depth requirement for walls, and the associated decreases in production & transportation efficiency?

Do you think that this will provide an impetus for low-rise residential construction to take a similar move, into 2x6 framing? Or maybe 2x4 + exterior continuous

Do you think that this takes attention away from the fact that air leakage are the predominant heat loss mechanisms in commercial & high-rise residential buildings, and in the case of high-rise commercial, window gains / losses as well?


As always, it feels like the desire to do the right thing is there, but the wrong people are advising on how to proceed. So far the ABAA only has air barrier requirements on the books for Wisconsin, Michigan, and Massachusetts. And most of the commercial high rise buildings I see only have wall insulation at the rim joists.

Architecture 2030 has a 50% reduction in energy consumption in new AND existing buildings as our 5 year goal, with 60% as the goal in the 5 years after that. I don't think that there is any level to which they can increase insulation requirements that will come anywhere meeting that goal, especially if all insulation levels require increases in production & transportation energy requirements, and increased cavity depths (increased use of building materials). We aren't winning the war against energy efficiency if the net carbon emissions don't change. We need something more dramatic.

For those that aren't familiar with Architecture 2030, it's an energy consumption standard designed to keep sea levels from rising to catastrophic levels by reducing the emission of buildings. If you would like to see how high the sea level can rise before your home is underwater, The Department of Geosciences at the University of Arizona have put together an online flooding simulator for the continental US. I recommend you check it out, especially if you live within 200 miles of the ocean:
http://geongrid.geo.arizona.edu/arci...rvi/viewer.htm

Did anyone read my anecdote about how replacing windows in old building stock (low-income rentals, factory conversion lofts) increases the standard of living to the point where the living spaces are valuable to homeowners that refuse to live in older buildings, thereby reducing the need for new building stock & demolition of old building stock? Has anyone thought outside the box lately?

Thanks

[BigLou80]

ok I will bite. I am not sure about the roof requirement as R30 is already required here. About the walls going from r11 in 16 oc to r19 24 oc. I am not sure what you did for math but I came up with a lot more the 5% in savings. How do you figure a decreas in production ? there are less studs to install.

No I don't think it takes away from the fact that buildings have lots of air leakage. Cheap or un educated builders who don't want to take the time to do it right take attention away from that. Same applies to windows
I think we need better window requirement but adding more insulation is a step in the right direction

I agree that a 50% reduction in energy consumption will be hard to do with insulation alone. It needs to include high efficiency equipment etc. I still don't see how you see it as an increse in building materials the board feet of lumber going in to studs is the same assuming you build 2x6 @ 24" oc. It also should not cost any more to ship the same number of board feet. Both sizes of lumber can be made from new growth trees. There are also ways to insulate you walls that don't add to carbon emissions like cellulose (made from tress which store carbon).

Something drastic does need to be done. Large tax credits to encouage people to improve the efficiency of existing housing stock would do a lot more to stimulate the economy then giving people checks to spend on forigen oil or chinese made goods.

Lou

[Martin Holladay]

Lou,
I certainly agree with you concerning the proposed $150 billion "stimulus package." Imagine what could be accomplished if the US government invested $150 billion in a nationwide weatherization program. Instead, Uncle Sam is handing out checks with the following advice: "Go shopping."
Oh, yeah, I forgot to mention -- it's money the government doesn't have. They want to borrow it from the Chinese, asking our children and grandchildren to pay the money back in the future, because we need to go shopping now. Sounds like a great solution to our current problems, caused by ten years of spending a little bit more than we earn each year.

[Dan Steinbok]

Lou
I understand your comment regarding equivalent board feet. It's good to hear that people are building 2x6 at 24" o.c. in your area. Around here, they've oversold the necessity of structural rigidity to the homeowner; we're looking at 2x6 at 16" o.c. as the norm.

My question is: to most people see this as significant progress? Or greenwashing? Insulative benefit has diminishing returns; especially in houses (even new houses in the US) where insulation is doing its job, but major heat losses are still occurring due to other mechanisms. Yes, the majority of buildings will not see much more than a 5% change is energy consumption as a result of the new requirements. And we know this anecdotally by the number of buildings we have seen with R-30 roofs and dissatisfied occupants.


With regards to a stimulus package: unfortunately, spending is an effective way to avoid recession, and it's cheap to do during a recession because interest rates are so low. Around here, our military spending has been quite a bit lower than yours, so we have plenty of cash on hand to take advantage of the low interest rates to invest in infrastructure. One of the big projects is actually going to be on 300 new marine wind turbines.

I'm not sure if anyone heard about this, but wind power was laughed off by the oil companies back in the day because the old global wind power surveys found that wind couldn't provide nearly as much energy as gas or nuclear. Unfortunately, all those studies were based on winds at 20 feet or so. They recalculated potential power at 150 ft, and the power potential grew exponentially. Denmark for example is now getting 18.5% of its power from wind turbines.

The next question: are energy efficiency goals going out the window if the recession progresses?