My fist step will be very good insulation. Likely closed cell foam. R40 ceiling, R30 walls and R30-R40 floor. Windows will energy saving also. I've read this book: http://www.amazon.com/Green-Ground-Sustainable-Energy-Efficient-Construction/dp/156158973X/ref=sr_1_1?ie=UTF8&qid=1407301829&sr=8-1&keywords=GREEN+FROM+THE+GROUND+UP
I also found found a lot of info/idea's on this site: http://www.level.org.nz/passive-design/


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One page 51 of the book is suggested that south facing windows should be 8-12% of the floor area of the room they are in. On page 52 they write about thermal mass and explain that when a home owner replaces a 1" pine floor with a 4"concrete floor a 50sqft window can be replaced with a 250 sqft window. To me that looks like contradicting information because a 50 to 250 area increase can never fith within the 8-12% range.

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Another thing I fail to understand is promoting large area's of glass. I don't know what the best possible R-value of glass is but I think it won't be higher than R3. That's way less than R30 of a wall. I understand the concept of solar gain during winter days but to capture that solar heat I need to replace parts of a R30 wall with R3 windows which only are usefull, in the winter during daytime. In the summer they let in unwanted heat and in the winter ights they cause more heat loss than a simple R30 wall. Of course nobody wants to live a windowless closed box but I'm just discussing the concept here and try to remove as many variables as possible. I'm sure people way smarter than me concluded thos big windows have real benefits but I would really like it if someone could give me some explanation.

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I'm not so sure it's even possible to build a real energy efficient home. I'm boxed in on 3 sides. A road on the east side. Houses/huge trees on the north and south side. A great view on the west side. To take advantage of solar gain during the winter, I need windows on the south but that direction is at least partly blocked by trees. I think that also greatly reduces the effient use of solar panels (heat, electricity)

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According to the website a great way of green cooling during the summer is making use of the prevailing wind with is mainly E, SE during the summer months. That forces me toward a certain internal layout of the house that may contradict with the solar heating (which I doubt is possible)

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Given the above is it really possible for me to go green besides good insulation and energy efficient equipment?

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I think think the theory is that if you can get a lot of solar heat gain through the windows and store it, then the gain is great than the loss you incur by having a large area of low R (high U) value glass.

Also of course, it is nice to have big windows with nice views!!!

IF you have low solar heat gain potential through the windows, you can still build an energy efficient home with a comfortable amount of windows.

Given the above is it really possible for me to go green besides good insulation and energy efficient equipment?

"Going Green" has more to it than just solar considerations. However, without southerly exposure, you really don't want to look at anything "solar"

I fear so ICF.
For me going green is trying to shave of that extra kWh in as many places as possible. Insulation, smart window placement, etc
If PV cells drop in price I might even place them at teh end of the garden. But I have to look into transportation loss first.

The vast majority of sprayed closed cell polyurethane foam in the US is blown with HFC245fa, which has a global warming potential (GWP) about 1000x that of CO2.  At higher R-values the lifecycle climate impact of the foam is greater than the carbon emissions it is offsetting by lower energy use.   Open cell polyurethane is blown with water, and uses less than half the amount of polymer per unit-R. 

Sheet foam insulation products have similar issues- XPS in the US is blown with large amounts of HFC134a (about 1400x CO2, used widely as an automotive air conditioning refrigerant, but now banned even for that application in the EU.)  The lowest impact foam sheet-foam products are EPS and polyisocyanurate, both of which are blown with pentane (at about 7x CO2).

R40 for the ceiling would not even meet IRC 2012 code minimum for US climate zones 4 & 5 (R49 or greater is required.) Indiana building codes have not yet been brought to IRC 2012 level for energy efficiency, and is currently based on IRC 2003, which only demands R38.

It is possible to buy windows with performance of about R3.5 (U0.28)  or even R4 (U0.25) without great expense.  Windows of R5 (U0.20) or better are available at a more significant increase, and would be recommended for homes with "whole-wall" (after factoring in the thermal bridging of structural framing) R-values of R30 or greater.  (The window manufacturer Paradigm has some reasonably priced U0.18 -U0.20 windows. There are others- the regional manufacturer Harvey has some, but I don't believe they are available in your area.)

Windows in the US are rated by U-factor (basically 1/R, averaging the performance over the whole window assembly, not just the center-glass), and a solar heat gain coefficient (abbreviated SHGC).  The number of low-E coated surfaces, the type of low-E coatings, and the gas used between the panes affects the final number.  When selecting windows it's useful to use different types on different sides of the house.  A low SGHC window is important for the east and west facing windows, because the low sun angle in the morning and evening creates unwanted gains, gains that you can't easily reduce with exterior shading.  But it's useful to have high SHGC windows on the south side, where roof overhangs can shade the window during the summer due to the higher angle of the sun, yet still allow wintertime mid-day gain to offset energy use.   All windows with an R value of 3 or higher (U-factor of U0.33 or lower) will have more wintertime heat gain than heat loss in your climate, even the north facing windows, but large amounts of window area will increase the overnight peak heat losses.  Balancing the amount of interior thermal mass become important with more glass area, to moderate the temperatures both day and night.

A reasonable starting point for "whole assembly" R-values from a long term energy cost savings basis can be found in Table 2, p10 of this document, broken down by US climate zone.  Of course the cost of achieving those performance numbers varies by insulation type and construction method, which means the financially rational crossover point will vary by quite a bit.  For example, closed cell polyurethane costs about $0.18/R-ft², whereas open blown cellulose costs about $0.03/R-ft².  Table 2 recommends R60 as a starting point for attics in climate zone 4, R65 for zone 5.  For a house with 2000 square feet of attic, getting to R60 with cellulose costs $3600, which would be cost effective. Getting to R60 with closed cell polyurethane would cost $21,000-22,000, which would be insane.

For comparative purposes, in very rough terms the costs of different insulation types is roughly:

Cellulose: open blown,  $0.03/R-ft²., dense packed $0.08-$0.14/R-ft².

Blown fiberglass:  open blown $0.04-$0.6/R-ft², dense packed $0.10-$0.15/R-ft².

Fiberglass batts: $0.04-$0.06/R-ft².

Stone wool batts: $0.05-$0.08/R-ft².

Rigid EPS foam board:  $0.08-$0.11/R-ft².

Rigid XPS foam board: 

Rigid polyisocyanurate foam board:  $0.08-$0.11/R-ft².

Spray polyurethane, 0.5lb per cubic foot density (open cell):  $0.10-$0.14/R-ft².

Spray polyurethane, 20lb per cubic foot density (closed cell):  $0.17-$0.20/R-ft².

Unlike that passive building website based in New Zealand, the prevailing winds in your part of  Indiana in summer are not from the east, and the summertime outdoor air dew points are too high to use night time ventilation as a cooling scheme (the summertime outdoor air is much drier in New Zealand than on the other side of the world in Indiana.) The majority of the time the wind will be coming from the south and west:

                                  Wind Directions Over the Entire Year

                  Fraction of Time Spent with Various Wind Directions

Thanks for the informative reply Dana.

The price difference is clear. But what about real life performance. I have a little experience with fiberglass batts and foam boards. Most of the time they aren't cut exact the right size which leaves gaps and in case of fiberglass compresses. Both lower the R value.
Fiberglass can moist and sags in over time. Both lower the R value. I do know spray foam has none of those issues. I can't really comment on the other forms of insulation.
Could you please repost your list based on real world performance in my climate zone?

Posted By NewHoosier on 13 Aug 2014 11:57 AM
Thanks for the informative reply Dana.

The price difference is clear. But what about real life performance. I have a little experience with fiberglass batts and foam boards. Most of the time they aren't cut exact the right size which leaves gaps and in case of fiberglass compresses. Both lower the R value.
Fiberglass can moist and sags in over time. Both lower the R value. I do know spray foam has none of those issues. I can't really comment on the other forms of insulation.
Could you please repost your list based on real world performance in my climate zone?

It's possible to install ANY of these insulation types in such a way that it under performs, and it's just as possible to install them such that they meet their performance numbers. It's possible to build very high performance buildings with any of them, or with the same type & amount of material build an underperforming air-leaky moisture susceptible moldy piece of crap. The difference is the competence of the designers & installers. 

Spray foam can shrink or crack, have long term outgassing problems or even catch on fire during the first hours of curing if not installed correctly.

Low density fiberglass is pretty crummy stuff and easy to screw up, but even that can be done is such a way that it performs.  Higher density fiberglass such dense-packed blowing wools are quite good. Higher density "cathedral ceiling" batts can also perform well over the long term if the installer is competent.  Key to getting the full thermal performance out of low density fiberglass is the tightness of the air-barriers on all sides of the material.

Low density open blown fiberglass or low-density batts are sufficiently translucent to infra-red to underperform by quite a bit in attics unless there is a top side air barrier.  These materials also suffer convective losses during the heating season unless bounded by air barrriers on both sides.  This is not a problem with dense-packed fiberglass or high-density batts (or with rock wool batts.)

Dense-packed cellulose if done at the proper density does not sag over time.  A researcher named Rasmussen at Aalborg University in Denmark has modeled how cellulose settles, and has determined the minimum density that would be required to be completely stable based on local climates and seasonal humidity changes, and published in peer reviewed journals.  You'll do just fine with 3lbs/cubic foot cellulose in Indiana, but would need 3.5-4lbs density in much colder US climate zone 7 where the wintertime moisture accumulations would be higher.

Low density open-blown cellulose will sag over the first decade or two, but when it nears it's final stable density it pretty much stops, and can be (quite cheaply) topped off if need be.  Competent & honest installers used the R-value at fully settled depth, not the initial depth. It will outperform it's rating until it settles in.  Unlike low density fiberglass it is opaque to infra-red radiation, and sufficiently air-retardent to not lose performance to convection. (In fact, blowing as little as 3" of cellulose on top of low density fiberglass "restores" the full performance of the fiberglass.)

Installing sheet foam correctly does not leave gaps- indeed the seams & edges would normally be sealed with tape or expanding can-foam.

Rigid polystyrene (and all fiber insulation above some minimum density, with air barriers on both sides) have increasing performance as the outdoor temperature falls, as does spray polyurethane.  Rigid polyisocyanurate suffers a fairly severe performance hit when the average temperature through the foam layer drops below 5-10C, but does extremely well when the average temperature through the layer is 10-15C.  In your climate a thin layer of polyiso on the exterior would underperform it's rated R by about 10% on average, but since polystyrene's performance increases at lower temperature, EPS/XPS will do better than it's rated R when placed on the exterior of a fiber or polyiso insulated house.  The approximate thermal conductivity at different average temperatures through the material layers can be seen below. The blue dotted line is the temperature at which the material is tested for R-value labeling purposes:



You will note that at 15C mid-foam temp or warmer polyiso even outperforms 2lb closed cell polyurethane at any given thickness, but below 5C mid-foam temp it is lower performance than cellulose.   

The wintertime outdoor average temperature in Connersville is about 0C, so with a 20C indoor temperature the average temperature through the wall in winter will be about 10C.  If the the exterior half of the R-value polyiso it's average temperature would be about 5C, which is where it's performance begins to suffer greatly as the temperatures fall further.  Making polyiso the interior half the total R would make it average about 15C, near it's peak performance.

XPS and closed cell polyurethane derive some of their performance (about 10-15% of R-value) from their climate-destructive HFC blowing agents, which bleeds out over time. After 50-75 years most of the blowing agent in XPS is gone, elimanating any performance advantage it may have had over EPS of the same density. (XPS in Europe is blown with CO2, and has identical thermal performance to EPS.)  I don't know how rapidly the blowing agents in ccSPF disappear, but it's likely to be less than a century.  Foil-faced polyiso retains some of it's pentane for more than a decade, which gives it a performance boost in the short term, and they are allowed to label it at R6.5/inch, even though in 50 years it will be about R6/inch (all at the 75F mid-foam temperature.)  The performance EPS is stable over time, since they lose the blowing agent within weeks of when it is manufactured.  Open cell foam does not get a performance boost from the water blowing agent, but it's gone within weeks anyway.

Most high performance home builders will use wood-framed walls (sometimes dual-walls) and fill it with dense-packed cellulose, dense-packed fiberglass or open cell polyurethane, sometime with exterior EPS or rigid stone wool or other foam to reduce the thermal bridging of the framing.  Katrin Klingenberg's  PassiveHouse in Urbana IL (similar climate to yours) has wall/roof/foundation stackups that look like this, which you will note, uses NO spray polyurethane, just dense-packed fiberglass and rigid EPS:

In your climate a thin layer of polyiso on the exterior would underperform it's rated R by about 10% on average, but since polystyrene's performance increases at lower temperature, EPS/XPS will do better than it's rated R when placed on the exterior of a fiber or polyiso insulated house.
......
In your climate a thin layer of polyiso on the exterior would underperform it's rated R by about 10% on average, but since polystyrene's performance increases at lower temperature, EPS/XPS will do better than it's rated R when placed on the exterior of a fiber or polyiso insulated house.

Let me see if I understand that correctly.
You advise a thin layer of PIC directly on the outside of the exterior wall. On top of that a layer of XPS or EPS?
How thick should each layer be for a R30 wall when ignoring the R-value of the wall itself. If I increase that to R60 should it just double both layers or should one be increased more than the other?

ICF are R22 wall. Unfortunately it's EPS insulation with should be the most outer layer if I understood you correctly. http://www.quadlock.com/green_building/ICF_energy_performance.htm
But according to this article it can also be:
Polyurethane foam (including soy-based foam)[2]
Cement-bonded wood fiber
Cement-bonded polystyrene beads
Cellular concrete

http://en.wikipedia.org/wiki/Insulating_concrete_form

Where does he get those wonderful graphs?

In your climate if you put a layer of polyiso alone on the exterior it will not perform at R6.5, it will probably average about R5, but lower during the coldest weather.  But if you put a layer EPS of similar thickness over the polyiso, it will A: outperform polyiso and B: improve the performance of the polysio.   The average temperature of the polyiso layer is also a function of the other insulation in the wall- you can't simply ignore the R-value of the wall.

An example of an  approximately R30 "whole-wall" using this technique would be a timber framed wall of 2x6 (1.5" x 5.5" true dimension) with the studs 16" on center, with R20 cellulose between the studs, 1/2" gypsum board on the interior, and 1/2" plywood sheathing.  Without the foam that comes in at an average of about R13-R14 after factoring in the thermal bridging of the studs.  On the exterior of the plywood goes 1.5" of polyiso (nominally R10 at the labeled value) and 1.5" of Type-II EPS, which is labeled at R6.3. Since the foam layers are continuous, with very low thermal bridging, we'll ignore the thermal bridging of the fasteners.  Add the foam layers up and that is a nominal R16.3, add that to the R14-ish framed wall and you are at about R30.

During the coldest typcial weather when it's -15C to -20C that outer layer of 1.5"  EPS will rise to about R7.2, but the polyiso layer's performance will drop to about R7.5, but that's still about R15 at the foam layers.  If instead the outer layer had been 3" of polyiso the performance of the foam layers would only be about R11 when it's -20C outdoors.  Using two layers and different types of foam gives you better average performance than 3" of EPS At 3" the wintertime average of EPS-only would only be a bit over R13.  It also beats the mid-winter average wintertime performance of 3" of polyiso, since at the lower temps the outer EPS outperform polyiso. That keeps the inner layer of polyiso a few degrees warmer preserving a higher R/inch for the polyiso layer.

ICF construction has pretty good performance, even at R22. But it's a thicker and more expensive wall than the timber-framed wall.  The thermal mass of the concrete gives a modest amount of performance improvement in your climate- it reduces the peak loads a bit, and from a total energy use point of view will be simlar to an R27-R28 "whole-wall" using lower thermal mass materials.  It's possible to build with higher R-values than that (Quad Lock and others have assymetric versions, with more EPS on the exterior than on the interior), but at a bit more than the 10cents/R-foot you would pay for sheet EPS.  ICF has many other good attributes that may be worth paying for- it can make a very quiet, very sturdy house that can survive high winds. A tornado may take the roof off and break all the windows, but the basic structure would still stand- it would be repairable.

Posted By ICFHybrid on 13 Aug 2014 04:26 PM
Where does he get those wonderful graphs?

The wind direction images are found on  Weatherspark.com's averages page for nearby Shelbyville IN.

The Klingenberg wall diagram comes up on a web-images search on the terms:  klingenberg house

I had remembered the I-joist stud fiberglass fill + EPS stackup  she used in her own house in Urbana and thought it a good example of a very high performance house that had used no spray foam.

If you know what you're looking for, search engines can get you there pretty quickly. eg:

Carter Scott (a local builder near me) uses double-studwalls and lots & lots of open cell foam, building Net-Zero-Energy homes in a climate somewhat cooler than Connorsville IN. He basically frames it out for the necessary wall thickness, then has the foam guys blast-away at it:



(^^ found by searching the terms: carter scott house ^^)

Most of his houses have R40-R50 walls, U0.20 windows and are heated with one mini-split per story, with NO auxilliary heating.  On some homes he will take that up to R60 using polyiso &/or 2-3" of ccSPF, but for most of them it's just 12-15" of open cell foam in double studwalls.

When spraying open cell foam a this thickness it is important to spray it in 5-6" lifts, not full depth in one shot. That keeps it from shrinking and cracking or catching on fire as it cures.

The full timber wall you described adds up to R30. How do I upgrade that to R60? Just increase the layer thicknes of polyiso and EPS in equal amounts? So for example both 3" thick (didn't calculate the correct thickness). Or should the polyiso layer stay at 1.5" and only the EPS layer gets thicker?


I like concrete so, if not to expensive I'll go for ICF of some kind. Polyiso should be directly on the wall and on top of that EPS. But because ICF is made of EPS it obviously means the insulation layer most close to the wall is EPS, not polyiso. Is that a problem? How to solve it? Add a layer of polyiso and another layer of EPS

When foam thickness exceeds ~5-6" it becomes more difficult to install, and the moment-arm of the fasteners supporting the siding requires more fasteners (== more thermal bridging.) Also, the cost of that much foam becomes un-economic.

To hit R60 in a cost-effective manner typically requires a double-studwall or Larsen Truss approach, or using I-joists as studs with 4-5" of exterior foam (as in Katrin Klingenberg's house.)

In your climate it's possible to hit Net Zero Energy at ~R35-R40 whole-wall with a PV array that still fits on the roof. Some builders in the New England region (US climate zones 5 & 6 (colder than your central Indiana climate) use what has been named the "Pretty Good House" (to distinguish it from PassivHaus or PassiveHouse), which is roughly R5 / R10 / R20 / R40 / R60 . That refers to R5 windows (U0.20), R10 foam under the basement slab, R20 for the foundation/basement walls, R40 (whole-wall) for the above grade walls, and R60 for the attic/roof.

Polyiso is hygroscopic, and prone to absorbing moisture over time when buried, which is why ICFs are never made with polyiso.

To get to "Pretty Good House" performance with ICF walls would be to start with an assymetric ICF that has 2.5" (~R10.5) EPS on the interior, and 4" of EPS (~R16.8) on the exterior. The EPS adds up to about R27.3, the concrete itself adds about R1, for about R28 total. To that add 1" of sheet polyiso on the interior (where it's warm enough to perform between R5 and R6.5), which brings it up to R34.5 whole-wall. The interior 2.5" EPS + 1" polyiso is nominally R17 nominal, as is the exterior 4" EPS, but since the average temperature through the EPS will be much cooler than 75F, it's average mid-winter performance of the exterior foam will be slightly more than R17.

An additional R0.5 of the interior finish wall gypsum brings the total up to R36, and depending on the siding type maybe another R0.5. While that is still 10% less than R40 at the additional performance gained by the thermal mass makes it roughly equivalent to R40 using lower-mass construction from an energy-use point of view, and slightly better than a low-mass R40 from a peak heating load point of view.

Quad-Lock has a 2.25" + 4" option for assymetric ICF, which they somewhat deceptively call "R30" (probably reflecting the mass-loaded "equivalent R" form some theoretical climate/siding/interior-finish), which would be an appropriate starting point. At 2.25" the interior side EPS is really only ~R9.5 instead of R10.5, but it doesn't much matter if your final wall is only ~R35 instead of R36 steady-state- it's still in the "Pretty Good House" range for total performance, and good enough to bring Net Zero Energy within reach at your location with a PV array that fits on the roof. 

If the rest of the design brings the individual room loads down to under 1000 BTU/hr @ +5F for the doored-off bedrooms, this type of house can be comfortably heated with one mini-split head per floor.  I was involved with retrofitting 3-story house to those levels in Worcester Massachusetts a couple of years ago, and it is heated with one ductless head per floor.  The only comfort issue is an east facing bedroom on the top floor that gets too much morning solar gain in June/July, and can overheat by late morning unless they keep the bedroom door open to the common area with the ductless head.  Exterior shades would fix that, but they haven't bothered- most summer days they get up before 10AM then leave the door open.)
It's only a problem when they want to sleep later.

RRRRR...

All those R's

R's have made a lot of people Rich. Problem is they really have little to do with Real world performance as Hoosier has expressed concern. I am not trying to contradicting anything that Dana said here, it is all good and sound information. I just want to point out that the sum of a wall's parts in R's may not be equal to the whole of its performance in $ or it may be much less. So why talk about the R's? As pointed out, the typical ICF wall typically performs beyond the sum of its R-value due to thermal mass loading. Other assemblies fair better or worse.

An "R60" wall in Indiana is IMHO a total waste of materials and money. Regardless of what the studies and charts say, there is a point of diminishing return with any insulation. Of all the points to insulate in a home, the walls are typically of the least importance unless in a high-wind location. Heat/cold do not travel well horizontally. Reflectivity, conductivity and mass are much more important in wall structure than "R" value is.

Just an example to think about. Would you rather spend a night in the desert in pup tent made of R-1 fiberglass insulation or a similar sized dome made of mylar film with an R-value of less than 1

If you were the Taliban trying to escape heat infrared thermal heat detection by US forces would you throw a space blanket over you or put on a pair of bluejeans (equivalent of dense pack cellulose)

Every building material has a purpose and a place. R values don't tell you how or where to use it and in many cases they have no appreciable R-value at all although they can provide a very green building envelope
R-values are not meant to rate all building materials.

From what the OP has said, GWP is not a concern for him. Most foam manufacturers are using all available means to reduce or eliminate Ozone depleting agents and some have achieved significant reduction.

In the wall construction shown in this thread for the Katrin net zero energy wall, OSB was used for interior structural purpose. I would contend that formaldehyde off-gassing and VOC's from the OSB are just as harmful to the environment as the small amount of pentane off-gassed from EPS manufacture or the GWP of spray applied CC Polyurethane foam. I'd rather live with GWP than be dead and never see it.

Both OSB manufacturers and foam producers are working to lessen these harmful elements. I like to look at the total embodied energy of the wall assembly. When this is taken into account, wood that is not locally harvested and processed becomes a pretty poor performe due to fossil fuel burned in the harvest, transport, processing, kilning, transport, warehousing and again on site transport processing and waste removal. EPS foam looks pretty good in this regard. Local field stone with a lime based mortar and a thermal break becomes a leader as does local logs and timbers.

Hoosier,

You must realize that the books you are reading are giving you general principles or rules of thumb to use as tools when designing for your application. South facing windows are not a great idea in Florida and North facing windows are not a great idea on the shores of Lake Superior. If you must have them for some reason, then you design ways to mitigate there negative effects. The wind does not blow the same way all the time. The Sun does not shine all the time and changes height seasonally. Design for averages, mitigate for extremes.

The land you build on will often dictate orientation and have a great deal of influence on material selection and use. Rather than trying to select one material as best and design a house around it, familiarize yourself with a broad range of techniques such as seasonal shading, materials and technologies such as LCD darkening windows etc. This will allow you to mitigate any potential issues you might have as they arise and not have to live in a boring, square, super-insulated box without any windows. Don't get frustrated there are a lot of "experts" and a lot of opinions and a lot of them aren't worth the paper or bandwidth they consumed.

The rules of thumb for window orientation and glazing are just guidelines to keep you within a reasonable box of expectation. If you move outside that box, you have to make modifications to other items to compensate and balance. Think of energy as a bowling bowl in the middle of a playground see-saw. Comfort sits on one side and cost sits on the other side. Your job is to keep it balanced, 18-22 C is the middle or balance point where both can live happily without the ball moving. Whatever is added or removed on one side you must compensate on the other as well. Keep the ball balanced. If you don't keep it balanced comfort will go down and costs will go up. The more temperate the climate, the easier balancing becomes.

1blue,

When someone (me) knows nothing books are a good start. Right now I'm absorbing info and when done I apply that info as good as possible without compromising to much or what I like. My house design isn't fixed. Maybe I like 15 designs equally well then I'll pick one that fits best in the energy saving guidelines. I liked a few extra bedrooms, but not if that means I'm taxed to death.

Some things to think about with passive thermal mass. If you are like my neighbor, who runs the heat and AC to maintain a fixed interior temperature at all times, then interior mass gains you nothing, no matter how much you have. On the other hand, even in my not super insulated house, the drywall alone is enough to provide significant effect (no AC yet this summer!). The primary effect of more mass would be to make thermostat setback (night and work days) not work so well (ie, would increase my energy costs all Winter). Insulating the thermal mass on both sides (ICF) is even more questionable. Summary - extra thermal mass can be positive, negative or neutral. Which one depends on a lot of assumptions.

My summer use for thermal mass during the summer was cool it down with a night breeze and them get free cold during the day. But given the moist hot nights that's not an option.
Solar gain could work by collecting heat during the day, then at night the heating could be switched off and the wall radiates the heat. (but when I wake up te wall needs to be warmed up again). Unfortunately I have no window on the South...
I think thermal mass is great if the heating/cooling doesn't have a stable temp.

The thermal mass in an ICF is isolated from the conditioned space, which is not an ideal placement of the thermal mass.

Nighttime ventilation schemes are never going to be a great way to cool a house in Connersville, no matter how much or house accessible the thermal mass is to the conditioned space due to the unacceptably high summertime outdoor dew points.

You don't need passive solar gain to make a house efficient. Low loss is sufficient, and that means an air-tight/high-R building envelope.

Getting to sufficiently high-R (R35-ish) to hit Net Zero with an ICF is one of the most expensive approaches, but cheaper than (wholly unnecessary) R60 by almost any means. Most PassiveHouse certified homes in US climate zone 5 do not have R60 walls (though most have higher than R40).

Katrin Klingenberg's home was the very first US PassiveHouse, and was not designed for Net Zero Energy (and so far as I know is NOT Net Zero), only PassiveHouse certification (which gives no credit for site-sourced energy). It is much higher-R than needed for Net Zero, and is over-designed from an insulation point of view even for PassiveHouse in her climate. (I suspect she overdesigned it intentionally to ensure certification. She could not afford to miss even slightly, since she was in the process of founding a PassiveHouse US standard, directly comparable to that of the PassivHaus Institut in Darmstadt Germany.) I know of a PassiveHouse in Shrewsbury MA with R100 walls using double-studwalls with dense-packed cellulose, but who cares? It was at least 2x overkill.

The notion that "Heat/cold do not travel well horizontally." as asserted by 1blueheron is in stark contrast to the well established physics of heat transfer. Heat moves from warm to cold, and knows no direction.

Methinks there is some confusion here about heat-transfer via convection-driven infiltration, where the buoyancy of warmer air causes it to escape out of leaks at the top of the house in winter, drawing in denser colder air though leaks near the bottom of the house. This is commonly referred to as "stack effect", and how combustion flues work.

In a house that even meets IRC 2012 tightness levels of 3 air exchanges per hour at 50 pascals ("3ACH/50") stack effect infiltration is still only a second-order effect relative to the whole heat load. Code minimum walls will still be losing far more heat than infiltration drives. But the higher-R the house is, if the air leakage doesn't tighten up, the larger the fraction of the total heat load it becomes. This is part of the rationale PassivHaus standard demands leakage to not exceed 0.6 ACH/50.

While 0.6 ACH/50 is a bit difficult for non-obsessed home builders to meet, 3ACH/50 is quite easy. In Canada houses built to their R2000 standard need to meet 2ACH/50, are relatively easy to build, and usually test between 1-1.5ACH/50. If building to "Pretty Good House" performance levels a target maximum leakage of 2ACH/50 is reasonable, and would be fairly easy to meet/beat. (The retrofit on the 3-story house I was involved with came in at about 1ACH/50.)

The notion that " Reflectivity, conductivity and mass are much more important in wall structure than "R" value is. " is similarly confused.
The very definition of R-value is the inverse of the entire thermal transfer (or U-factor) of the assembly. Reflectivity of the surface of wall assemblies is of almost vanishingly small importance, and the higher-R the assembly, the less important it becomes. Roof reflectivity is of some importance for energy use during the summer, but vanishingly small in the winter. Reflectivity of the either the exterior or interior side finishes/surfaces of walls is of immeasurably small importance to the total heat gain/loss or energy use. The thermal mass of the wall is of only secondary importance at the edge of zone 4/5, especially if that mass can't freely take/give heat to the rest of the house due to interior-side insulation as in the ICF case.

The thermal mass in an ICF is isolated from the conditioned space, which is not an ideal placement of the thermal mass.

I'm aware of that. Considering I can't make much se of passive it may be acceptable. Or just drop the whole idea of ICF and just pour in formwork or use something without insulation.

Nighttime ventilation schemes are never going to be a great way to cool a house in Connersville, no matter how much or house accessible the thermal mass is to the conditioned space due to the unacceptably high summertime outdoor dew points.

I know. It was merely a short recep of what I learned sofar.

You don't need passive solar gain to make a house efficient. Low loss is sufficient, and that means an air-tight/high-R building envelope.

Agreed. But I just try to get a few % engergy savings at as many places as possible.

Getting to sufficiently high-R (R35-ish) to hit Net Zero with an ICF is one of the most expensive approaches,

That's another problem for me. I have no clue what a completed shell with variosu materials costs. ICF likely are costly but then you alreay have nice insulation. Formwork (sp?) may be cheaper but takes more manhours. Wood I don't trust. It's just so hard to chance my mindset. If I read stuff like "add moist barrier", "add product x against air leaks" I always get a feeling like: Ifa construction needs such gimmicks isn't a good construction. On one hand I'm stingy. On the other hand I've inherited the overdimensioning virus of my father. His work lasts forever. I just like a bit of safety margin. I think it pays of in the long run. Especially because I'm not a person that's gonna maintain my house. I'm not gonna hunt for airleaks every year. No need to imo. A house of brick/concrete and good frames just lasts and lasts. Well that's my expeience in my country.