well at least as close as possible. I started looking into building my own home at first it was to be sonething simple than came across some sustainable princyples than came across Passiv Haus, the ideea has changed so much it looks nothing like I first envisioned, and while I was hoping to have decided on something by spring the snow will melt soon and I am just as confused as ever. I like the PH standard as it can be aplied to any type of construction yet it is not so simple to implement, for example in the US stick building is pretty tipical so I thought that would be a good place to start, double stud walls would do the trick, but how about the roof and floor? ICF seems to be popular, here but compared to PH standards it is barely insulated and the whole concept of thermal mass in the middle I'm not so sure about, granted is better than regular concrete just not sure it's good enough, some PH foundations I read about employed 16 inches of foundation foam. I looked at earthships for a while but for Michigan I'm not so sure, they employ lots of glass and for Michigan plain double panes net negative also all that thermal mass and earth berming might actually net negative too or so it seems. Initially when I bought the lot my neighbour gave me a pole building book and that was what I was initially considering, that or a log house. but that was before I have learned about PH. I thought I was onto something with the pole design but I am afraid at PH levels of insulation it will weigh too much. So I am back to a blank page again, idealy I was considering following the double stud wall ideea all arround but gravity is a bitch, any thoughts for the roof and floors paralel chord trusses may do, not perfect but I wonder how would they hold up with heavy snow and R 100 celulose?

It's common for Larsen-Truss houses to be built with the wall-cellulose being continuous with the attic cellulose without substantial thermal bridging at the intersection of the top of the wall and the attic. The key distinction between a Larsen Truss and a double studwall approach is that the interior stud-like chord elements are the structural portion of the house, and the outer truss chord is only holding up the siding & containing the insulation.

In areas where code requires fire-blocking in the walls making a continuous cellulose layer from the foundation up & over the attic floor is technically a violation (though not dangerous, due to the high air-retardency of the cellulose), but where inspectors object the fire-blocking can be met without undue thermal bridging by using cut up rigid rock-wool panels rather than wood for the fire-stops.

R100 cellulose isn't really all that difficult to support unless you're trying to support it on the cheap with gypsum. This is not a difficult or expensive engineering problem.

The notion that "...plain double panes net negative..." simply isn't true, for any code-legal U-factor. (t's true for some 1978 vintage clear-glass double-panes that had a U-factor of U0.6 or slightly higher, but literally ANY U0.35 window will be net-positive on solar gain, even on the north side of the house (!). In MI you won't be able to hit PH levels of energy without making use of the sun, but they'll likely need to be very tight triple panes with U-factors of U0.20 or lower. Hitting Net Zero Energy is a lot easier than PassiveHouse, spending some of the insulation & window-money on grid-tied PV instead, and heating/cooling with high-efficiency ductless air source heat pumps (mini-splits), to leverage that grid-power by a factor of three or better (which is do-able in most of MI, but maybe not quite 3:1 in the coldest parts of the U.P.).

thanks for getting involved, as usual I had to read your post twice to make sure I did not miss something important, I came across the Larsen Truss before they have strips connecting the 2 chords? I did not realise only the inner one was structural I have to go back and look at it again, I know you advocate celulose for all the right reason and I am al for it, it's not the gipsum that concerns me but rather the entire load, I was debating a pole house not sure if it can hold up, may need a different foundation but all the other types pose thermal bridging difficulties to the ground.

recently considered maybe a two storry but that adds up to more load per pole allthou overall is less materials, all in all not really decided on a foundation type or anything for that matter still looking into various types to build see which ones fit together better

just so I am not confused a net zero house is similar to a PH just not so efficient but it makes up with on site energy production? if that is the case that is what I was going for all along, I look at PH for inspiration, I haven't yet considered getting certified just a goal to aim for, while onsite renewables were always in the plan the idea was to reduce the load to a minimum first and PH is a good goal to set for that.

I'd hate to disagree with you on the windows but the reason I strayed towards PH is that I ran the numbers and plain double panes score a net negative in januarry on a south wall, maybe my math got screwed up, maybe with some special coatings would bearly break even, granted over the course of the year they will net positive its januarry that concerned me most and this year we had 1600 HDD in januarry with a base of 70F which is where we tend to keep our house so its a bit more realistic than the common 65F. On the north side of the house I don't know how would any window score a net positive you got me baffeled here, maybe if you count the snow glare or some special landscaping, either way we had the idea of not bothering with any north west and east windows just south, and with passive solar shading in mind it works kindof odd last drawing worked out to a thin 3 foot strip 6 feet above floor, saw a few designes that way I'm fine with it, bit odd not beeing able to see outside other than the sky, I'm 5'8'' wife is 5', but in some of the pictures I saw of homes done that way the room was surprisingly well lit better than the common glass at eye level design,

just like it was discussed in other threads a service cavity does not concern me we figured out a way to lay our floor plan with only one pluming wall and all wireing can be routed through the inner walls, I was planning on clean outer walls roof and floor, I'd like to have a clean slate roof with no perforations, not even the drain breather so that is something in the works on how to go about, all in all I like the idea of a design as passive as I can afford it, just trying to get as far away from depending on a service or another, I have utilities on site but at the moment I am not taking them into consideration looking at them as more of a backup.

So Larsen Trusses is one way to go about it, I'll be reading up on it and see what I can come up with

Download a copy of Resfen (any version) to determine the net energy performance of any window at your location & shading factors by entering the window's specifications.

http://windows.lbl.gov/software/resfen/resfen.html

Even sky radiation on the north side of the house provides a net heat gain with U0.35 or lower windows, as long as it's a hard-coat low-E as opposed to soft-coat. That's true even in most of Canada, and surely in MI. (I doubt you can even BUY soft-coat low-E windows off the shelf in MI- they'd have to ship them from Florida or Texas.) The north side gains aren't worth farming, and an all south glazing approach can work, but it's worth having at least some daylighting in the other parts of the house. This guy near me went net-zero (off grid, no less) with only south facing glass:

http://www.telegram.com/article/20140112/NEWS/301129990/0

Carter Scott's Net Zero approach uses windows on all sides, and sometimes with most of the glass on the north side:

http://transformations-inc.com/communities/transformations/devens/

Using 70F as a heating degree day base is completely bogus, unless you keep the interior temperature above 75F 24/7. Every occupied has some internal heat sources (even if it's just the humans sitting in the dark) and some amount of solar gain, and all homes have some amount of thermal mass on the interior to average it all out. The most commonly used HDD base is 65F, which is the approximate heating/cooling balance point for a typical ~1200' 1950s US home with single pane windows and R11 batts in both the walls and attic that is kept at 70F indoors. High performance homes will often have balance points south of 60F, even homes that are extremely parsimonious on electricity use.

Some Larsen Trusses use both chords for structure, most don't. Some use a stepped down fat foundation, others flat.  The original design by Larsen was as retrofit to a pre-existing structure.  It's an easier sell to inspectors to have a fully structural 2x4 or 2x6 framing as the interior side chord, and put the bulk of the insulation on the exterior side, with the insulation side somewhat cantilevered off the foundation (which gets exterior EPS treatment under the cellulose wall.)

I just read through this article http://www.greenfret.com/house/larsen.html, bit more modest than what I had in mind but several times better than the 1960 ranch I now live in, you do have a point I guess with the HDD, my whole thought process when calculating window heat loss was that the inside air was 70F regardless of source, therefore the delta T would be a bit more acurate at 70F,

at the same time I am on a bit of a budget and I have considered getting a decent doouble pane instead, its only the few coldest days of the year that they netted negative , and that was for the month of january for plain glass, co coatings no gas, I asume the triples will have a significant cost upgrade especially with the FANCY frames, that is still to be debated when I get arround to that chapter we'll see what is left in the budget but the though of getting something double pane crossed my mind and maybe upgrade 10 years down the road.

back to the larsen truss I did come across that picture before bu only now noticed that the outer truss/chord is hanging outside the foundation, the one project I posted above looked like the flat foundation type, as for thermal bridging looks like the plywood connector plates are it and the top and bottom plates, not sure what exactly the rock wool you spoke of for fireproofing looks like I asume its not structural it would not be able to replace the top plywood cavity closure would it?

in some sense this is very simmilar to what I had last come to only that employed double the floor joists, double the roof rafters, I got to find some detail on how they tie into roofs and such.

thanks for getting me started, I had seen this before but ruled it out as another double wall

came across this http://www.builditsolar.com/Projects/SolarHomes/LarsenTruss/History.htm a while back an quickly ruled it out, the walls themselve don't look bad just the floor and roof connection bit of a thermal bridge, guess some compromises must be made, what I had in mind involved a lot more wood and weight, some good pointers ADA, did not know that was a known procedure to effectively seal up a house, I like the pro pink stuff, maybe there are other better products, and no sheathing on the outside but rather cross bracing. good reading