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Thursday, July 6, 2017

The Odd Insulation Math of US Department of Energy, Home Energy Scores

The following is public sharing of one persons' trial of US Department of Energy's Home Energy Scores Tool. The tool is a product of SRA International, Inc., in public ownership through US Government contract.


In a first post, I address access to the HES tool, and then finding of odd math of USDOE in dealing with a divide-by-zero problem in conversion of R-value to U-value, done stupidly as simply a number inversion of the insulation-only R-value. Energy is transmitted through resistances in addition to those of conduction through insulation and framing. The additional "surface" resistances are substantial and well known, though variable in every path. Where the savings achievable in any bid of weatherization must not be over-estimated, a highest value of surface resistance generally applicable, is wanted. In a derivation of Insulation Math , I show that the wanted round number as a resistance value in USA units, is 3. This number has never been questioned, in ten years of submission to highest quality of peer review. And yet, USDOE (persons at Lawrence Berkeley Lab), set a wildly low surface resistances number, 0.4. Colorado Energy is prominently found in a general Google search in this subject. Build It Solar also works with the numbers, not contradicting my analysis, as I see it. 

As insulation varies in effectiveness from full to worthless, energy waste changes in linear fashion in proportion to a Transmission Coefficient, U. A realistic particular situation must be considered to understand consequences of the USDOE error. Let that situation be a 2x4 @16 framed wall with at best R15 full filling of insulation .



With best insulation and correct usage of value 3 surface resistance, computed U-values are reasonably close, 0.063 my number vs. 0.087 by USDOE.  With worst insulation, none, 
my U-value is 0.316, just a bit less than if a wispy wall had no framing thickness, U=1/3. At this condition the USDOE U-value is 2.28, over-estimating energy transmission and heating cost by a multiple of 7.2, roughly 3/0.4 = 7.5. Aside from other allowance by a Insulation Derate Tool, the wrong USDOE math will lead to excessive shaming of found conditions and to large over-estimate of weatherization benefits.  The whole USDOE process will fail to discover and report that perfect, fullest placement of insulation is absolutely required in weatherization. Perfect full-filling coverage is far more important than insulation depth or available thickness. The USDOE hire-an-interest-conflicted-auditor process will often lead to hiring of the auditor to pile more crummy insulation on top of a bad situation not repaired, doing more harm than good.



Content at this post will grow as I critically examine and try tools and the scoring process. Large errors found, will justify this examination.

Content for Home Energy Assessor Candidates is at beta.homeenergyscore3dtraining.com.
As I work in this online as a candidate, I am forced to employ a laptop computer with 64-bit OS and with unbearable difficulty of scrolling on the small screen. Offline I transfer lessons learned to my capable desktop computer running 32-bit but with large screen and other needed advantages. I must choose a 32-bit OS and hence 32-bit browsers with the desktop setup. I employ 32-bit to not give up important old software. HES training resources behave better on this full size desktop computer, employing the links that follow.

Primary Resources:

Introduction Video

Sim User's Manual

Step-By-Step Guide to Training House #1

Step-By-Step Guide to Training House #2

Home Energy Score Overview (Part II Study Guide)

Assessor Calculator
A URL for the calculator download is not offered. The online download is an Excel 2010 file usable only with Microsoft Office 2007 and newer. Such commercial offering is inconsistent with US Government policy. Here then is a free version of the calculator:

Secondary Resources:

Part 1: About This Home

Part 2: Roof, Attic & Foundation

Part 3: Walls

Part 4: Windows & Skylights

Part 5: HVAC & DHW Systems






Remaining content is accessible only to those admitted to the beta web site.

3D Practical Training

House #1

House #2

House #3


3D Practical Test

Multiple Choice Test

User Review
(Submit feedback to SRA.)


Assessing The Assessor Calculator Tool:
The goal for existing home energy efficiency ratings shall be that anyone can find a score by himself if such has value, and with that believingly see how home improvements can move the score. Improvement is the need, not assignment of nonsense scores that do not motivate home improvements. There must not just be instead, an enrichment of cooperating organizations and auditors, in an absurd system. A home owner must find only self interest in the engagement with home-quality scoring mandates. We must not tolerate any involvement of persons not thinking first of the home owner interest.

Please see calculation as I perform it, superimposed on the insulation averaging portion of the HES calculator: 


Applied math is evident in spreadsheet cell definitions:
For each of several parallel paths:
A pathway contribution of U-Value where all pathways add to 100% of path areas: This is simply (Fraction of Total) * (Path U-value). I can readily define as many parallel paths as are needed, typically four or more.

The HES Averaging Calculator imagines at most three parallel paths and poses for each a computed value UA, for example at Cell B30:
UA =B29/IF(B28=0,0.4,B28)

where B29 is a path's percentage of the total of all path areas, and B28 is the R-value of that path and has value not less than 0.4.

For this path in the first column at the Google Sheets link, HES computes 1.250 for a tiny piece of uninsulated drywall, an evil access hatch, and I correctly compute Ui = 0.005*0.333 = 0.00167, and 100*Ui = 0.167.

Average U-value, called "Cavity U-Factor," is simply the sum of values of (Fraction of Total) * (Path U-value). Instead, the tool poses a calculation such as:
B38 =(IF(B30=0,0,B30)+IF(B33=0,0,B33)+IF(B36=0,0,B36))/(IF(B30=0,0,B29)+IF(B33=0,0,B32)+IF(B36=0,0,B35))
computed by HES calculator for this path as U = 0.074, then inverted as R = 13.52. 

For this attic floor with well-placed R19 batts, joist thermal shorts and, a little uninsulated hatch, I correctly compute U = 0.0519, then resolved as inverse minus 3, value R = 16.28.  At the next column, see that if the hatch is fully insulated R19, floor values change very little: U = 0.0504, R = 16.83.

We must counter false statements such as this of 1999, Don’t leave a hole in the ceiling ,  passed along by Habitat for Humanity, as written by southface.org:. It is way past time that the offending web page should be deleted or disconnected. Attic access is necessary, not evil. USDOE and Lawrence Berkeley Lab have not gotten the message. In wanting to demonstrate evil of a hatch if without an absurd stapled batt-on-top, the training considers a hatch 5% of floor area, perhaps of dimension 2 ft by 25 ft with a 1000 sf floor!


I wonder about behavior of complex if-statement HES calculator cell definitions that avoid a divide-by-zero problem. Examine this with study of a 2x4 wall that is well insulated with R16 batts, then with increasing decrepitude of the insulation batts as missing or not in contact with bypass:
Observe linear drop-off of value with decrepitude. Present again the tables at the top of this post:


There is not a razor's edge transition with "no insulation," but there are odd results if input no-insulation R-values in the HES calculator are less than 0.4. There is only an up to times seven error in U-value and energy cost with decrepit insulation (see discussion at top of post).

Now examine a crude provision for decrepit insulation in HES Calculator.
Here is a screen capture of the Excel form of the calculator, with function selectors in four tabs at bottom.





















Where the Insulation De-rate Calculator is dysfunctional in the free version of the calculator, look instead for taught methods of USDOE perhaps mandated in Home Energy Scores, at an Insul-calcs tab now visible. 


Here, defy an unfounded and outmoded bias for blown cellulose and against all batt insulation. Want well-placed insulation of highest quality as in filling a 2x4 wall to R15, regardless of insulation form . Completely filling the wall is what matters, then stilling bypass in convective loops.A rater may not be commanded to believe the HES calculator.

Assessment must allow  there is never instruction to give allowance for joist thermal shorts or for any decrepitude, as one might then do, shown here. In fact a subsequent step of derating insulation forbids direct allowances.

 

Fair and Poor installations may in fact have large areas without insulation contact, hidden from view and having no value. Regardless, the visually-interpreted table penalties are too small.

Tuesday, June 27, 2017

Flawed Measurement Of R-Value With A Certainteed InsulSafe4 Gage

I want to at last dispose a gage saved from a job in which I concluded the following:
The Builders Statement of found insulation states that for intended R38, one bag covers 44 sq ft. 37 bags were applied, sufficient for 1628 sq ft. The installer was unaware of actual area  2315 sq ft, then with 30% under-fill,  R26 before discount for overwhelming consequences of missing insulation.




General fill of insulation was 10", not a goal of about 15".  A greater depth of insulation did not exist at time of construction, then lost by settling. A failure of inspection occurred, on top of a perhaps-conscious failure of math. Was compensation for the job not proportional to cost of materials?



Adjacent to the found access hole where inspection would be expected, the gage is revealed at 10" depth. By human nature, depth is less at a majority of area not accessible for inspection.







Here is a cropped photo of the gage, with marking of depths at values of common interest, a black line and arrow under-lining each named value.  For example, named value R60 is at depth 22.0".The gage corresponds to a table in PDF document InsulSafe® SP Installation Guide - CertainTeed .












































Having insulation generally R26 where R38 was wanted, is mean. Call the weighted average of loose fill R24.  The overall effective R value of the attic floor is diminished by areas bare of insulation and by thermal equalization of interior walls through assorted floor openings often large. Bare areas are mainly at edges of the attic, and are typically 5% of floor area.

Do the Insulation Math , of found effective R-value:

Allow for thermal shorts of 2x8@24" framing.

1/(Reff + 3) = fjoists/(Rjoists +3) + finsulation in contact/(Rinsulation +3) + fbare/3
For 2x8 framing, Rjoists is  6.8.
1/(Reff + 3) = 0.06/9.8 + .89/27 + .05/3


Reff = 15

The work of sealing the attic floor is an insulation cost, and I think the expenditure should be encouraged by allowing its result is that of finding another 5% floor bare area:


1/(Reff + 3) = fjoists/(Rjoists +3) + finsulation in contact/(Rinsulation +3) + fbare/3

1/(Reff + 3) = 0.06/9.8 + .84/27 + .10/3


Found attic floor insulation:
Reff = 11

The now-accessible attic has a large decked area 18.6" up from ceiling drywall, and much additional area accessible with movable flooring upon raised floor supports. HVAC ducts are more efficient and are buried under floor insulation where allowed. Conditioned space below the attic floor is 2315 sq ft.





































A section of hallway ceiling ruined by step-though during electronics wiring is now occupied by a wonderful European attic ladder.




















Ladder installation at a 45° diagonal across 2x8 floor joists is supported by 2x18 box beams, a first-ever feat of cleverness.





















I imagine a 150 sq ft work room 8' tall from the new flooring level, at the attic space with greatest headroom. The space might be a wood shop or music room, conditioned or not. An attic has congenial temperature a portion of most days of the year.





















With dispersed insulation,  fbare is zero. One bag of R21 insulation, 89 sq ft, 89/2315 = 4% of the floor, is placed over the master bedroom loft ceiling. 5% of the floor at eaves is insulated to R30 with pushed loose fill. The remaining loose fill is 3" to 4" deep everywhere else, called R11.

1/(Reff + 3) = 0.06/9.8 + .04/24 + .05/33 + 0.85/14


In the now-accessible attic:
Reff = 11.

This is the same as-found, not diminished. Where this condition must exist for some time, my churn of insulation beyond just creating safe attic access, has not hurt my customer. This finding is very important to me. I hope you agree with my math. Distributing insulation to eliminate bare areas is smart, even where found unstable loose fill insulation is collapsed in the churning.















Find then:
Perfect, fullest placement of insulation is absolutely required in weatherization. Perfect full-filling coverage is far more important than insulation depth or available thickness. Where insulation has been placed carelessly, do not hesitate to trample insulation if necessary, to perfect the installation. Never delegate placement of insulation to be done without caring, in haste. The value of insulation placement is proportional to time spent.

Back to that now-disposed gage then. Don't believe it, even where it reads correctly in perhaps revealing fraud. Diligent work is harder to gage.

Friday, June 2, 2017

Math Assessment Of Poorly-Placed Insulation

Please watch evolution of this post-under-construction, in demonstration of  Math of insulation payback assessment and qualification of rebates  . Please follow the link of that Google search, at top finding my work.  It is an important subject, in which there is an absence of academic contribution. Math shows that we can not afford to place insulation carelessly. 

We will find that perfect, fullest placement of insulation is absolutely required in weatherization. Perfect full-filling coverage is far more important than insulation depth or available thickness. Where insulation has been placed carelessly, do not hesitate to trample insulation if necessary, to perfect the installation. Never delegate placement of insulation to be done without caring, in haste. The value of insulation placement is proportional to time spent.

My most-recent customer, May 2017,  wanted storage space in a truss attic, where the home has no basement, and half of the garage is converted to needed living space.

Photos are drawn from a corresponding Google Photos album .

This home had the usual drywall plunker 18" OSB-skirted access hole. There was no safe landing to move between trusses, from the blunt OSB edge. To move, one had to angle feet to opposing angled truss elements, in long steps across trusses.



















About 20% of the plunker area was bare about the precariously-stapled R38 batt, and this really mattered to actual insulation value:

1/(Reff + 3) = .8/41 + .2/3

Reff = 8.6.

A batt on a plunker is ridiculous, dangerous, and often temporary. I continue to do good service in safety of attic access, contending for better building codes , and imagining and building very-simple factory-built hatches that cost no more than the plunker-hole. I prefer to install a wonderful attic ladder, then with every safety feature I can imagine.

I am the first person up here since house construction in 2004, and the home owner has cause to trust that I can make this space useful. There is 15" of loose-fill insulation seemingly almost the required R38. HVAC ducts are strapped-up, for the insulation blow, and are very much in the way.




Good lighting and safe access via ladder is accomplished early in a job. A pretty Fakro LTK 22/47 insulated attic ladder is rigidly mounted with the beginning of 18" box beams at both sides. Outer beam faces are 16" rips of 3/4" plywood. There is a step-off well 9" up from the ceiling.



























Preview the accomplished attic improvement equally for usefulness, and energy conservation. Up 18.6" from ceiling drywall, there is very much useful space. New and more-efficient HVAC ducts are almost entirely buried, for their safety and better insulation value, without compromise of floor insulation value.  Effective R value of the entire attic floor is now better than R49. Four 900 lumens Sylvania LED disk downlights brightly illuminate the safe, clean, useful attic.




















Finished features include a strong, level shelf over a loft cathedral ceiling, making that space useful and safe. Find and exploit every advantage for walking between truss elements. The shelf and flooring constitute a large box beam that restrains this gable wall and adjacent trusses against roll-over in a tornado.




















Braces set for alignments during construction are not intended to guard against roll-over of trusses and great tragedy in a tornado. Useful new braces are not in the way of access.



















Diagonal bracing against truss rollover is by example of MiTek, USA, MII-GE90-001 .



I have provided the safe, useful storage space that the home owner needed.

Now step back to the work in progress, with demonstration that easily-achieved energy savings are the best reason for the attic conversion. We all can and must afford the best energy efficiencies achievable in our lives. Where one is able to find an honest craftsman or is able to follow freely-offered example, an investment in a durable sixty years and more, chunk of energy independence in our homes, is a significant increment of personal wealth.

This home had complex found conditions. 43% of floor area had askew thick batts, 51% was between trusses with poured loose-fill fiberglass, and 6% was with thermal shorting of truss framing. Two loft cathedral ceilings add elegance to second-floor rooms without the compromise of roof integrity and access limitations of common cathedral construction. Loft cathedrals are easy with truss design but seem to need evolution for improved weatherization.
































This collage is of found conditions of R31 and R38 batts of the West loft cathedral.









































This collage is of found conditions of R31 batts of the East loft cathedral, and of repair underway under tight hostile conditions with nasty roof nails and danger of falling through drywall. Temporary wood-strip supports and access via a new storage table over the loft were important to holding a good attitude for repairs completed in a half day.








































Among the R38 batts of the West loft cathedral, see awful consequence of poor batt placement and failure to block thermal shorts at framing. With 50% contact, the weighted average insulation level is only R3.



















1/(Reff + 3) = fjoists/(Rjoists +3) + fbatts in contact/(Rbatts +3) + fbare/3
For 2x4 framing, Rjoists is 3.3 .
1/(Reff + 3) = 0.06/6.3 + .47/41 + .47/3
Reff = 2.6

Find the same result, ignoring joist thermal shorts.
1/(Reff + 3) = .5/3 + .5/41

Reff = 2.6


Bare areas dominate the math, overwhelming significance of the framing thermal shorts. Therefore, apply the formula above for the entire attic floor, with glib allowance for joist thermal shorting, whether or not there may be insulation "atop" conductive complex truss framing. Joist thermal shorts remain important in most cathedral ceilings, where a rare reader might amend the math with larger value of Rjoists . Consistent math is achieved by use of an OpenOfficeCalc spreadsheet. Please find that spreadsheet for the first computed result, with 2x4 @24 joists, fbare=, 0, R19, at Google Drive .


About half of intended insulation value is lost where the bare area fraction is just 5%. About two thirds is lost where bare area fraction is 10%.  About three fourths is lost where bare area fraction is 15%. Even 5% sloppiness is an unbearable insult to home occupants, not justified by any offsetting construction economy.

The table above applies in general, for a floor with a single layer of batts, or a floor with loose fill insulation. In the table, 6% of floor area is treated as 2x4 joist thermal shorts, R = 3.3. Where bare areas strongly dominate the math, the treatment of thermal shorts is of no consequence. My immediate self interest in the table treats the question whether my rebates organization, Energy Trust Of Oregon , will grant my customer an insulation rebate. Rebate offers are the only offered encouragement of actions by my customers. A rebate is offered only where found insulation has value less than R12.

In another edit of the example spreadsheet , imagine compromise of insulation in a 2x10@24 cathedral ceiling with R19 batts 50% bypassed. Find Reff = 2.3. All insulation that doesn't fill enclosing space has questionable value. Try out your own favorite worry. I wait with skepticism, to study methods in new USDOE Home Energy Score software, hoping that penalties will cause end of ruinous venting with deliberate under-fill of cathedral ceilings.


Bare areas in an attic add up fast. In most homes, expect 5% of the floor area bare, at carelessly insulated eaves. See attic walls in the photo above, with loft cathedrals at left and right, insulation uselessly bridging the wall framing.Those uninsulated  attic walls at interior sides of loft cathedrals alone are more than 10% of floor area, and treatment of those walls can not be separated from overall attic improvement.




Bare areas under floor insulation are another 10% of the attic floor, mainly in awful result of blindly stuffing oversize batts before setting drywall, at the loft cathedrals.

Carelessness is the cause of energy waste in this home, in defiance of building codes in effect at home construction in 2004. And, until I showed up to imagine a useful attic, all seemed well. Any inspector or other weatherization contractor would have seen a good-looking attic with no corrections needed. The attic is a dangerous place. Stay out! 








I move further beyond the R12 threshold for a rebate, at fbare = 0.15 (see table above), if a bare area equivalent 5% of the attic floor area, is added. This is proposed as a standard allowance to encourage sealing of attic floors. 

Payback Math, Insulation Improved Effective Insulation Value Starting  R10, Ending R49:
Apply Insulation Math that gives understandable dollar values then easily scaled for a home, heating means and climate, that matters to you. Basis math is for a home with 88%-efficient natural gas heating, 4400 heating degree days, energy cost $2 per therm.

Annual Cost of Heat =  (.00002 * 4400 * 24  / .88) * (Area/R)  = 2.4* (Area/R)

Let Area = 1200 sf, and R = 1/U = Reff +3.

For the attic floor, the first-year saving of heating cost is $222 - 55 = $167.

Attic walls, the exposed ends of loft cathedrals are another 100 sf, improved from less than R4, to R30. Here the first-year saving of heating cost is $34 - 7 = $27.

Total first-year savings are $194.

In considering savings on into the future, one must account for the rising cost of easy energy through scarcity. Apply Perpetuity Math . The present value of an investment yielding $194 in the first year and continuing indefinitely, is more than $8500, first-year times 44, with a twenty-year outlook and true cost of energy rising at 10% per year. My invoice of $6100 was a bearable cost for wonderful new storage space. All of the cost, including a bit of excess for the storage, is in fact a very profitable investment.

Rebates As Incentive
Once again a rebate application is in process with Energy Trust Of Oregon, for my work. I have asked $296 for the floor insulation, and $30 for the attic wall insulation. $326 total, 5% of job cost. This is a small return of the home owners' thirteen years of contribution to Oregon's Public Purpose fund, a 3% tax upon natural gas and electricity bills.


As I understand it, rebates in fact are not needed as incentives. We just want to know priority of the things-to-do, to be able to afford the work and to trust that it is done honestly, to endure. Incentives are not working to drive weatherization of existing homes, where Energy Trust will promote fewer than 1000 attic insulation improvements in 2017.

Despite need to multiply its productivity times fifty, or go out of business, Energy Trust definitely wills that the described attic would have been left alone. I am commanded in Specifications , that:

IN 1.13—Determination of Existing R-Values

The total R-Value for a floor or an attic shall be calculated based on the depth of the insulation (in inches) multiplied by the recognized R-Value per inch of the insulation material.
15" times R2.2 per inch for loose-fill, is R33. Rebate Denied. And that is the end of a conversation. My customer may receive the asked rebate, but Energy Trust will learn nothing, and will not contact me, for its benefit or as a disciplinary action. Meantime there is some strange complexity  offered in Specifications Appendix A:

APPENDIX A: WEIGHTED ATTIC R-VALUE TABLES
These tables shall be used to determine the weighted R-Value of a single attic space with varying levels of insulation. These figures are determined by using a weighted average R-Value calculation without including framing assembly U-Values:
U-Value (U) = 1 ÷ R-Value
Area (A) = area in sq. ft.
Weighted R-Value = 1 ÷ [(U1A1 + U2A2) ÷ (A1 + A2)]

In cases where the existing insulation level is R-0, an R-Value of R-1 is used in its place to determine weighted R-Value.

This math is of course in error, where convection heat transfer coefficients and resistance to heat conduction through surface materials add up always to nearly 3. A low number for convection and surface resistances is a bad idea, for it leads to over-estimate of savings achieved where there was little or no insulation at found conditions. A modestly high value, 3, gives desired under-estimate of savings achieved. Add 3 to all insulation effective R-values and then invert the result, to obtain U-Values. Please see discussion of such concerns at Wikipedia , and ColoradoEnergy.org . Compare savings from insulating a 1200 sf attic from no insulation to R49, assigning 1 or 3 as found effective R-value, 1/U, U = 1 or U = 1/3

$2.4*1200*(1 or 1/3) = $2880 or $960, at found conditions.
$2.4*1200/50 = $58 at R49.

No one would think to mislead, in offering that another $2000 per year is saved. The only math offered by Energy Trust for mixes of insulation then is incorrect. No correspondence to dollar savings is suggested. There are internet links at Fine HomeBuilding and elsewhere to USDOE math of payback calculation, now broken. The missing information handicaps decision making for weatherization. In particular, the treatment of out-of-contact insulation is not addressed, leaving some to think contact doesn't matter. Surely the correct treatment of insulation out of contact and permissive of air bypass driven by heat input and rejection, is to fully discount any value of the insulation.

Tragedy In A Typical 1970s Town Home

Many 1970s homes are dominated by cathedral ceilings that have no actual insulation value. This is the first home I will address with USDOE Home Energy Assessment software. What direction will I find for this condition in 2x10@24 ceilings? I have seen clues that the insulation will not be counted.




















The exterior walls of 2x4@16 construction have insulation nearly as poor.This small area at a removed air conditioner, fixed with removal of exterior sheathing, may be the model, unaffordable repair, saving $6 per year at cost of $600.







































It may be evident that this home has a personal connection to me. Bitterness about the cathedral ceiling and wall insulation seemingly not treatable, motivated two of the ten proposals for 2018 revision of the International Energy Conservation Code, at Louisville , that I offered and personally defended at great cost. Please find a February 2016 summary of my correspondence with IECC , where I responded at the best of my ability to all editing suggestions. At this code cycle IECC newly offered an online submittal process, cdpAccess, and supported my telephone and email newbie needs. At the conference, I relied on my own printing of proposals vs. existing 2015 code, as in this abbreviated printing for followup discussion with NAIMA. I sorted through a tall stack of paper-printed code and revision in competition with experienced professionals using laptop computers, trying to follow all proceedings that mattered to me.

My proposal 11881 offered:
R402.2.1 Over-fill of insulation. Wherever possible, insulation shall be confined on all six sides. Insulation fill shall be complete and without voids that could allow air bypass of the insulation. Overfill of insulation shall be required to achieve complete insulation fill. In addition to installation methods that prevent voids within the insulation, the methods shall prevent the presence of air spaces between a barrier film such as the kraft facing of a batt or the containment mesh for blown cellulose, and hard wall coverings such as drywall.


At the eaves of an attic, insulation installation methods shall achieve as much insulation R-value as possible toward exterior wall headers. The eaves shall be packed tight with insulation and overfilled except the resulting R-value at these locations shall not be required to exceed R-value required for the adjacent ceiling.

My proposal 11882 offered:
R402.2.2 (N1102.2.2)  Ceilings without attic spaces. Such spaces, commonly called cathedral ceilings, have depth limited to that of practical roof framing. They are to be crafted with all of the seriousness of any other conditioned attic, concerned for roof rot in insulation at temperature below the dew point where moist air may pass. A solution for insulation, in well-applied closed-cell foam, must be seen as risky in the event of roofing failure. These spaces shall not be violated by can lights or provisions for attic ventilation and foolish wish to cool composition shingles. There shall be no compromise of required insulation value.


With these provisions, any persisting construction of cathedral ceilings shall be with acceptance composition shingle roofing is not allowed.

My proposal 11859 offered:
R402.2.3 Eave baffle and insulation provisions. Where needed at soffit vents, a solid baffle durable for service of at least sixty years, shall hold insulation at bay, while allowing a stable maximum amount of insulation to be placed. The airflow resistance of each baffled path shall be less than that of its screened vent. Soffit vent paths installed as pre-made "bird block" and designed for placement at every frame bay, shall be placed in every frame bay.  


For new home construction and in tear-down remodels, eave baffles and at least all eave-edge ceiling insulation shall be placed before installation of ceiling-edge drywall, if needed to assure thorough  insulation, in areas that become inaccessible. Where an attic eave extends to a cathedral ceiling or other roof-over-conditioned spaces, do not employ the insulated cathedral ceiling cavity as passage to admit air for attic venting. 

Altogether, these three proposals dealt with my concerns of deficient and irreparable poor construction of the 1970s depicted in the town home photos above.

All ten of my proposals were unanimously disapproved, sometimes with enmity and sometimes with sympathy expressed by other conference attendees. It was awful. Seeking solace from ICC long after, I was chided for not doubling my investment in another try at the final hearings in Kansas City. My goal instead is to develop alliances for another try in submissions for 2021 IECC. Alliances are needed to combat a little army of obstructors seasonally hired to work the hearings, by the National Association Of Home Builders, aiming to squirrel every possible nickel to pockets of big-time builders. I especially need to find a working relationship with NAIMA , the successful obstructor of the batt-overfill proposal. NAIMA must admit for example, that R13 batts are grandly inappropriate in 2x4 exterior walls, never being 3.5" thick as-placed, and possibly of no value.

Please see that math is integral to my contributions for USA responsibility to conserve energy now wasted in our generally-shoddy homes. Please see that regulation in building codes applies only to new homes and major renovation. Energy conservation is not regulated thereafter.

Note to Self: Anticipate a review in Summer 2017, of consequences of 2018 IECC changes approved, by US Department Of Energy. The report may be like that issued for 2015 changes, in August 2014, which did not reveal any useful math.
PNNL-23438
https://www.energycodes.gov/sites/default/files/documents/2015_IECC_preliminaryDeterminationAnalysis.pdf 

Issued by Battelle Pacific Northwest National Laboratory, Richland, WA.