Thanks for your comments!
It makes perfect sense about lower insulation not being as effective as the side insulation due to the idea that warm air moves upward and of course convection is more prominent above the grade, but there is some conduction that happens in the basement - I am certain that is the case here.
Right now I am trying to heat the ground below with the air just above it - which I know is not entirely dry - with a heat pump - and that is some of the waste of heating this home. I am 100% certain insulation under that slab would have paid for itself during the nearly 10 years we have lived here. One of our lessons here about efficiency is concerning windows. We love the outdoors and because of that, we overglazed. We have good windows, but good windows are what, the equivalent of R3?
I am still stuck on the roof part for the new design - steel = $$ and living roof = structural support for heavy loads which is of course $$$. Even if I consider ferro cement or a geodome roof under consideration, which might save $ in construction costs, either involves paying a consulting civil engineer to put his stamp on it for the bldg. inspector., which will be at least $$. I could make it a shed roof to decrease roofing costs which I have considered, but any reasonable pitch to offset snow loads puts the South side quite high, increasing air volume which would decrease efficiency dramatically. This is another area I need to consider some.
Passive solar storage---> I have just thought of a new (to me) way of working with this. The idea involves heat storage UNDER the foundation, not on the sides or parallel to the structure as is most often discussed. Think of an insulated basement full of dry sand insulated from 8' down to above grade to a N/S block wall vented slab with external solar collectors running a closed loop buried coil at about 6' below grade. Like I said, I have a great deal of issues to work out on this idea - and don't know if its been done or not, but my idea is to apply the concepts of accumulated solar energy storage, but avoid the moisture control issues of living in essentially, a walk-out basement with Southern exposure. I am probably going to be learning a lot about Passive heat storage volume calculations shortly.
For humidity and fresh air options in the unreasonable season, I will be using some sort of heat recovery ventilator - probably not a commercial model, but rather a non-electric system of some sort. Again, another piece of the puzzle to work out - and there are a lot of them: Convection, conduction, radiation, storage timing, and of course the monotonous code requirements - some of which a variance may be necessary since much of code still assumes a growing economy from fossil fuels, which is a questionable forecast, at best.
Aesthetics and comfort of course is important, but our primary goal is an attempt at using -0- energy for heating and off-the-grid sustainable power for all else. Can it be done up here? I don't know, but I'm very likely going to attempt it sooner rather than later.
Also: wanted to add that I just got back from the library. I checked out 5 books:
Got Sun? Go Solar by Ewing & Pratt.
The Straw Bale House by Steen, Steen & Bainbridge w/Eisenberg
The Passive Solar House by Kachadorian
The Superinsulated Home Book by Nisson & Dutt
Sun/Earth Buffering and Superinsulation by Booth, Booth & Boyles
I hope to have this info digested and notes summarized in a few weeks. I am bound to learn something from every one of them and every one of you, so up front right here and now I just want to say thanks to all participating and of course to Mr. Paul who is keeping it real
. solarguy (Troy): Today
I am very much favoring going super-insulated using a load bearing 2-string straw bale system (R~55) on all 4 sides and essentially atop what is a frost-free insulated slab. I still have a lot to work out, but I am going for 100% passive solar heating efficiency
I admit that I have not seen this showcased yet in any design in the entire state, so my challenge is laid out in front of me.
I think we have pretty much settled on a house plan layout that is <700 sq. ft. interior dimensions.
I expect that all the windows I will put in, I will do so by installing on both the inside and outside of the bale wall (e.g. *2* double pane windows in each location with the inside window being slightly larger than the exterior window on the South side. I already have a bunch of windows I got for free that I can use for this so we should be golden (or nearly) there.
There will be a double wall UV stabilized polycarbonate greenhouse incorporated into the design of this house on part of the South side of the house - which will probably incorporate a 3-way vestibule - in the case of windows that are on the inside of that barrier (interior of hay bale house side, no need to put in the second window, as that envelope will suffice for slowing the heat loss of the interior window. If I find it doesn't, on go additional windows. In the case of one code required egress window outside of the greenhouse, I will work out other details for that.
I agree that cellulose trumps fiberglass. Depending on what code requires, and/or what is practical to build within our budget constraints (which is quite small), we may incorporate cellulose for roof insulation. I wish we would have used that here, but I will let another owner update that for this house if they so wish. This home would be best occupied by a family of 4 or more for full occupancy of the house.
Heating with a biodiesel stove = that is awesome!
I will comment more once I have spoken to the building inspector and get a heads up on what I can or cannot do in the location where I plan on building. I may be building this year (probably) or next, or later if something really unusual happens - you never know - whenever this happens, I will definitely post pics of the info on here when I actually get going on it.