We are looking into building a new home and shop in one. We are thinking of a 80 by 50 with 16ft sidewalls. I have looked at using lvl or lsl studs to be able to get 16ft tall then use closed cell insulation to get the R value we want. I also have looked into using sips for the project. We will heat the floors either with i electric LP or Geothermal. What does everyone suggest? What do you all recommend for the frost wall ICF or just a poured wall or even a block wall with insulation on both sides. I want it to be comfortable and affordable but where do you stop spending money to save?? Lots of choices just having a hard time deciding what will work best. Thanks for the great site have done a lot of reading and trying to understand what will work best for us. Thanks

Closed cell foam thermally bridged by framing is a waste of foam, since the framing provides such huge ~R1/inch bridge through the ~R6/inch foam. For a 2x6 wall it adds only ~R2 to the "whole-wall R" performance over what half-pound open cell foam or mid-density fiberglass or cellulose at typical framing fractions. The environmental impact of closed cell foam is also pretty high, EXTREMLELY high when it's blown with the industry standard HFC245fa blowing agent. There are much lower impact HFO1234ze blown closed cell foams now becoming available, but there is still about twice the amount of polymer per R as with open cell foam.

Where are you located? Local climate makes a large difference in what R-values, wall & roof material stackups, and heating sources would make sense.

I’m located in Eastern Iowa just outside Davenport. Thanks for the help

Davenport is on the cool edge of US climate zone 5A:

http://www.greenbuildingadvisor.com/sites/default/files/images/DOE%20climate%20zone%20map.preview.jpg

An IRC code minimum wall (= the crummiest performing wall that's legal to build) in zone 5A would be 2x4/R13 + R5 continuous insulation, or 2x6/R20 :

https://up.codes/viewer/utah/irc-2015/chapter/11/re-energy-efficiency#N1102.1.2

With the 2x4/R13 + R5 option with R5 insulation on the exterior of the structural sheathing there is sufficient dew point control at the sheathing layer than you can use standard latex paint on wallboard as the vapor retarder, which gives the assembly much better drying capability. If you go to 2x6/R20 it would take at least R7.5 on the exterior for dew point control in your climate:

https://up.codes/viewer/utah/irc-2015/chapter/7/wall-covering#R702.7.1

The 2x6/R20 + R7.5 (or more) solution would beat code-minimum with good margin. Using open cell foam in the cavity helps make it air tight, but any doubled up top plates, jack studs, etc, would have to be caulked at the seams with a high quality sealant (polyurethane caulk is good.) If using fiber insulation caulking the framing to the sheathing for the full perimeter of each stud bay, and taping any sheathing seams with the appropriate air sealing tapes would be in order.

While 1.5" XPS is labeled R7.5, it loses performance over time as it's evironmentally damaging HFC blowing agents diffuse out, eventually hitting R6.3. Using 2" EPS would be R8.4 today, and R8.4 even after 50 years, usually blown with fairly benign hydrocarbons (pentane variants are popular) , most of which leaves the foam quickly and is recaptured at the factory. To hang siding over 2" or thicker foam, through screw some 1x4 furring to the studs with 5" long pancake head timber screws, 16" or 24" on center, hanging the siding on the furring. (If using thicker foam you'll need longer screws, sufficient to penetrate 1.5" into the stud, minimum. To take the sting out of the cost of the foam, buy reclaimed foam. At 2" or more any type of foam would have sufficient dew point control for 2x6 framing. The stuff is out there- sometimes you have to dig a bit to find a reclaimer near you, but it's usually less than 1/3 the cost of virgin stock goods. There are reclaimers operating in IA, IL, and WI, near you- some can be found in these searches:

https://desmoines.craigslist.org/search/sss?query=rigid+insulation

https://dubuque.craigslist.org/search/sss?query=rigid+insulation

https://madison.craigslist.org/search/sss?query=rigid+insulation

https://rockford.craigslist.org/search/sss?query=rigid+insulation

A minimalist 2.25" + 2.25" insulted concrete form (ICF) stem wall for a slab-on grade building can work out just fine with 2-3" of rigid foam on a 2x6 studwall, with the bottom plate located such that the wall foam is 1/4" or so to the exterior of the exterior EPS of the ICF, which allows the ICF to be finished with a cementicious protective layer such as QuiKrete Foam Coating or similar. That makes the foam thermal break over the bottom plate complete.

Use an EPDM sill gasket between the bottom plate & foundation, not a cheap foamy thing. They seal much better, and form a reliable capillary break to protect the wood from moisture wicking up from the footing.

Thanks I'm sure I will have more questions as we get closer what are your thoughts on heating it?

Thanks I'm sure I will have more questions as we get closer what are your thoughts on heating it?

What are your fuel options (and prices?)

In cheap-power country a radiant slab floor under floor thermostat control to keep the floor comfy for bare feet while controlling the room air temperatures with ducted or ductless air source mini-split heat pumps can be a good compromise in operating cost/comfort. With better than code windows and better than code air tightness just the heat pumps can be good enough for most people.

Getting to the optimal heating system starts with an AGGRESSIVE room-by-room Manual-J heat load calculation.

In your location going with double-low-E double-panes with an "extra" pyroltyic coating on surface #4 (the surface in contact with the room air), and an SHGC >0.5 is a worthwhile comfort & efficiency upgrade even on an otherwise code-minimum house. Cardinal's LoE180 + i89 glass works, and is available from several window companies (IIRC, including Pella). But there are others. The U-factor of the glass is about U0.20-U-0.22, maybe as high as U0.24 for the whole window. In climates colder than yours this glass would result in too much window condensation during the coldest weather, and you'd need a triple pane to hit that sort of performance level, but not in IA. (Code-min is U0.32, which is ~50% more heat loss from the windows.)

Lp is roughly $1.50 a little cheaper this year but on average. I can get electricity for heating for 6.5 cents a KW for heating or operating a geothermal system I dont think that works for operating split systems.

Wow both of your rates are about 1/2 of mine.

Assuming a ductless heat pump with an as-used HSPF of 9 (9000 BTU per kwh), a million BTU of heat pumped into the house takes 1,000,000/9,000= 111 kwh, which at 6.5 cents/kwh costs $7.22/MMBTU

A gallon of propane has 91,600 BTU of source fuel energy, burned at 95% efficiency in a condensing boiler delivers 0.95 x 91,600= 87,000 BTU/gallon into the house. A million BTU then takes 1,000,000 / 87,000= 11.5 gallons, which at $1.50/gallon costs $17.25 / MMBTU, more than twice as much.

An HSPF of 9 would be middle-of-the-road performance in your climate for a brand name cold climate multi-zone ductless heat pump. Optimally sized there are are some that will do a bit better than that. Individual single zone mini-split can do quite a bit better- many rated in the HSPF 12-15 range.

An electric boiler has an HSPF of 3.41, which is nearly 3x as expensive as heating with an HSPF 9 heat pump, and a bit more expensive than heating with a propane boiler, but it's first cost and maintenance costs are much lower than a propane boiler. If radiant floors are something you really want an electric boiler is probably the right way to go given your low retail electricity prices, but even at 6.5 cents/kwh it will be worthwhile to do most of the heating with cold climate heat pumps (despite the higher initial cost), since they also air condition at very high efficiency.

While air source heat pumps won't quite match the efficiency of geothermal heat pumps in your climate, the first cost is much lower, and the design risk is also lower. Every geothermal system is a semi-custiom design, and the actual efficiency (and reliability) is in the hands of the system designer. Mini-splits are a mass produced pre-engineered commodity with predictable performance, and fewer ways to screw it up (though the more idiot-proof they make something, the more creative the idiots become... :-) ).

With the heat loads carefully calculated it's possible to focus in a bit closer on potential systems and models, but it looks like in your local energy market heat pump solutions are going to be the sweet spot, whether air-source or geothermal.