Posted By sailawayrb on 27 Nov 2013 06:42 PM
I should also add that while I am a huge fan of ICF buildings, I have little love for Passive House standards. My feeling is that any building that looks that ugly will never be loved and maintained long-term no matter how well it performs. Just to set the record straight...

I don't believe anything justifies UGLY but I guess that is in the eye of the beholder. On the other hand I don't think people should whine about the public not wanting to pay for efficient homes when these homes are something only a mother (or the builder) can love.

Posted By ILikeDirt on 28 Nov 2013 04:55 PM
Aha! Found what I was looking for: http://www.nudura.com/en/icf-wall-technology/oneseries.aspx

Albuquerque is zone 4, but just barely. Areas immediately north and east are zone 5.

Thanks for the roof suggestions. Great info.

Why is that Nudura form what you are looking for?

It's only R-10 and states it's for pools, elevator shafts, anywhere that only one side of foam is required.

You won't pass code with that form if you are using it on an exterior wall.

FBBP, happy thanksgiving a month late. Still digesting my feast. In the unintended consequences dept, having the kitchen of my dreams is not good for the waist line.
Gotta say that changing the DD day less misleading because only change during winter in mass walls is hvac sizing. Changing r value implies that energy use is reduced, which isn't the case.

Ilikedirt, I got a building permit using mass enhanced r values for nearest modeled city, rather than the wall's steady state R-10. You should check first with the building inspector, but your average NM official should understand mass effect if it's understood anywhere. You have the dynamics backward for exposed interior mass.You need it to moderate heat or cold events inside the home, which is significantly hindered by interior ICF foam. For example, with a double oven going most of the day yesterday, my house stayed flatline 70. The flip side: Interior mass that has cooled too much -- it will happen -- isn't going to warm very fast either. A kiva, or adobe fireplace, was the historic answer in NM. Passive solar is also an answer, and absolutely requires exposed interior mass of correct proportion. Sailawayrb can help you with that.

In energy terms, there's not much difference between one sided nudura or your cmu blocks with internal foam and NM SOP foam sheathing over cmu. Go with local experience. If you have folks who can parge stucco and plaster, the interior foam blocks might have a lower overall cost because you skip siding and drywall and stucco skips a step as well.Finally, google UCLA and HEED. It's an energy model that's pretty easy to use and has R-10 cement wall and ICF options. It's best way to avoid Chevy vs Ford arguments.

That's exactly what I was thinking, toddm. I want the exposed mass to moderate interior-originated heat and cold events. Obviously more exterior insulation would be better (all else being equal), but my impression right now is that in a climate like northern NM that is well suited for it, it would be better to expose the mass at the cost of some whole-wall R-value. An ICF that consisted of 6 inches of concrete on the inside and 4 or more inches of foam on the outside would be just wonderful.

Posted By Lbear on 29 Nov 2013 02:26 AM

Posted By ILikeDirt on 28 Nov 2013 04:55 PM
Aha! Found what I was looking for: http://www.nudura.com/en/icf-wall-technology/oneseries.aspx

Albuquerque is zone 4, but just barely. Areas immediately north and east are zone 5.

Thanks for the roof suggestions. Great info.

Why is that Nudura form what you are looking for?

It's only R-10 and states it's for pools, elevator shafts, anywhere that only one side of foam is required.

You won't pass code with that form if you are using it on an exterior wall.

Sure he would:  R-8 c.i. is code-min for mass walls under IRC 2012  in Climate zone 4 where more than 50% of the R-value is to the exterior of the mass.  It wouldn't cut it for marine zone 3 though (you'd R13 c.i. there.)

Not that 25% over code-min R is a particularly high performance wall assembly.  Nudura DOES have 2" inserts for their forms, adding another ~R8 bringing the total foam-R up to about R18.  An R18 nominal mass wall with 100% of the R exterior to the thermal mass would probably outperform an 2.5" +2.5" ICF in an Albuquerque, since the thermal mass isn't isolated from the interior, and better able to take advantage of the solar gain from windows. 

Nudura also offers 4" and 6" inserts, but from a lifecycle cost-effectiveness point of view it may be better to spend the money elsewhere other than wall-R at ICF-R pricing in that climate.  See page 23 in the catalog. (The one-sided ICFs are on page 20.)  The one-sided ICF with a 2" insert would meet IRC 2012 code min in any US climate zone, (though there is probably a rationale for the 4" or 6"  inserts in zones 7 & 8).   The One-sided IC + 2" insert is a bit over 2x code min for climate zone 4.

Sure he would:  R-8 c.i. is code-min for mass walls under IRC 2012  in Climate zone 4 where more than 50% of the R-value is to the exterior of the mass.  It wouldn't cut it for marine zone 3 though (you'd R13 c.i. there.)

Not that 25% over code-min R is a particularly high performance wall assembly.  Nudura DOES have 2" inserts for their forms, adding another ~R8 bringing the total foam-R up to about R18.  An R18 nominal mass wall with 100% of the R exterior to the thermal mass would probably outperform an 2.5" +2.5" ICF in an Albuquerque, since the thermal mass isn't isolated from the interior, and better able to take advantage of the solar gain from windows. 

Nudura also offers 4" and 6" inserts, but from a lifecycle cost-effectiveness point of view it may be better to spend the money elsewhere other than wall-R at ICF-R pricing in that climate.  See page 23 in the catalog. (The one-sided ICFs are on page 20.)  The one-sided ICF with a 2" insert would meet IRC 2012 code min in any US climate zone, (though there is probably a rationale for the 4" or 6"  inserts in zones 7 & 8).   The One-sided IC + 2" insert is a bit over 2x code min for climate zone 4.

Yep, that sounds like exactly what I'm looking for: 4" or so of exterior foam with a 6" concrete inner face.

ILikeDirt, we have a suite of free DIY passive solar design software that you may find useful for your project:

Borst Heat Loss Analysis Software

Borst Passive Solar Altitude Angle Software

Borst Roof Overhang Design Software

Borst Passive Solar Fenestration Exposure Software

Borst Passive Solar Heat Gain Software

Borst Passive Solar Thermal Mass Performance Software

Borst Integrated Heating System Performance Software

Please be sure to read the associated directions for each software application before using. These software applications are JavaScript based and just use your trusted browser to run so there is no downloading of files, mining of personal data, etc.

I think I mentioned this previously, but you may want to consider some of the TFSystem vertical ICF products that appear well suited for passive solar interior thermal mass and hydronic radiant wall heating (or active wall R-value boosting using solar hydronic heat). I have attached a photo of one of their products showing how PEX can be easily placed, how any thickness of EPS you need can be used on external side, and how you can have bare concrete (via removable plastic pouring pans) on internal side or have a standard wall cavity for electrical/plumbing.

Full discloser...we are NOT affiliated with TFSystems in any way and we have NOT actually used any of their products yet. We will be using their products for a passive solar multi-building project this April, so will have a better sense of how well they actually install and perform then. The Nudura product looks very promising too. Don't know how easy it would be to place PEX though?

Thank you so much, sailawayrb. Those calculators look pretty amazing, though I'll admit they're a bit intimidating for a novice like myself. I'm still reading the instructions! I (and possibly others?) would love to hear how your project goes. Are you planning to do the walls with no interior insulation, or with only a small amount? I guess the trapped-air stud cavity itself that you can put the utilities into is probably a tiny bit of insulation all on its own.

FBBP, it is mostly the boxy look and feel of most Passive House designs that are a turn off to me. Ugly might be too strong a word, but my dad is an architect and I likely have a similar eye... The Passive House performance goals are certainly inspirational and worthwhile. However, I believe the standards are very rigid and consumers are overly paying for the improved performance given the middle man certification approach. So I don't believe Passive House or other similar "certified" building approaches currently offer good ROI or an acceptable tradeoff (to me) between livability and cost of obtaining performance.

I am a fan of high performance, single story, ranch style ICF homes that can take full advantage of integrated passive solar and hydronic radiant floor heating. Of course, you need a larger property foot print for this approach and your cost per SF will be slightly higher than the multi-story approach. However, long term maintenance is easier and less costly and your house will always be fully accessible to you as you age. A well done building envelope, thoughtful use of fenestration quantity and placement, and flexible/thoughtful application of free energy (passive solar) or low cost energy (PV and hydroelectric) available at the building location can readily approach, meet or exceed Passive House standards depending on how much you want to spend while still being a much more attractive and cost efficient approach.

Posted By ILikeDirt on 29 Nov 2013 12:57 PM
Thank you so much, sailawayrb. Those calculators look pretty amazing, though I'll admit they're a bit intimidating for a novice like myself. I'm still reading the instructions! I (and possibly others?) would love to hear how your project goes. Are you planning to do the walls with no interior insulation, or with only a small amount? I guess the trapped-air stud cavity itself that you can put the utilities into is probably a tiny bit of insulation all on its own.

You are more than welcome ILikeDirt and happy to help. This project will be a mix. We need some walls to host electrical/plumbing and other walls will be faced either with brick or stone...still waiting for client to make final decision.

I would offer our consultation or design services, but my husband informed me that we are pretty well booked up for our 2014 season and he really wants to take a vaction this year unlike last year. These software applications are actually relatively easy to use once you play with them and read the instructions.