My wife and I are looking at the possibility of building a SIP home in Missouri.  We are have a generic understanding of the product and are looking for information on plans, costs and process.  Also any helpful suggestions people may have related to thier real experience in building thier SIP home.  Also, does anyone have real life examples post the building process what the true cost per square foot is.

Thanks
Daniel

I recently built a 1,600 sq. ft. addition using SIP walls. I was a Homeowner GC for the project; I have an environmental consulting and publishing background. I researched SIPs extensively before making the decision to use them. Another couple in our area built a SIP home and I visited their construction site and interviewed them as well. They weren't convinced the SIP floors and roof were worth it, for them anyway, but other than that they were happy with the SIPs. Note I'm in VA where we don't experience too much extreme weather.

Running the numbers, I found SIPs to be less expensive when you considered "all of the costs." You save significantly on labor compared to stick-built walls although the local builders and General Contractors I interviewed tried to convince me otherwise. You also save on waste disposal and the associated labor moving trash around. In addition, the electrical rough-in went very fast since the electrical chases were pre-cut.

We “hung” the second floor joists within the structure to significantly reduce potential energy loss and increase strength.

When designing the roof trusses, I increased the “heal height” (where the roof meets the top wall plate) by a foot. Why? The extra foot of space on top of the wall plate (basically, in the attic) allows more attic insulation where you need it; at the pinch point where the roof meets the walls. According to several energy efficiency studies I came across while researching, homes lose a lot of energy where the insulation basically goes to zero thickness where the roof line meets the walls. This made sense to me so I had the truss engineers add the extra heal height. It didn’t add much to the costs of the roof trusses. I have additional information about the project on one of my blogs. I don't know the policy associated with posting links on this forum. If it is OK, I'll be glad to share my posts for you.

I'm interested in your cost numbers. I'm familar with SIPS, have used in the past, but have found material & installation costs higher when compared to stick framing similar R values, all things ocnsidered. DId you install them yourself? how did you find doing the wiring?

Not looking for actual numbers necesarily but how they compared with stick.

I've been doing similar research. Leaning toward SIPS because of energy savings and net cost savings, but it's evident that steel SIPS are the way to go. As for cost comparison, I haven't been able to find actual numbers -- obviously everything is so custom -- but I did find this table that shows a relative comparison. The table is at the bottom of the page. This site seemed to have a lot of other good info too.
http://hi-techbuilding.com/economical/

Posted By DTS on 02 Mar 2014 12:08 PM
. This site seemed to have a lot of other good info too.
http://hi-techbuilding.com/economical/

The above is technically not a SIP.

Posted By DTS on 02 Mar 2014 12:08 PM
I've been doing similar research. Leaning toward SIPS because of energy savings and net cost savings, but it's evident that steel SIPS are the way to go. As for cost comparison, I haven't been able to find actual numbers -- obviously everything is so custom -- but I did find this table that shows a relative comparison. The table is at the bottom of the page. This site seemed to have a lot of other good info too.
http://hi-techbuilding.com/economical/

A claimed "effective" R value of R33 for 5-1/2" of EPS foam?  Yeah, right.  It would be closer to R22 if you ignore the fact that the foam has highly conductive steel studs penetrating 1.5" into the foam.  If this was tested as an assembly, it would probably come in closer to R18, or about half of the claimed "effective" R value.

Agreed. EPS has an approximate R value =4; wood =1, so in a 6-1/2" assembly, 5.5x4=22 + .5x1 + .5x1 = R23, ignoring the steel. This "effective" business is a phoney sales pitch; don't fall for it.

My wife and I recently built a 2800 square ft house with 8 inch SIPs. I researched and calculated everything before we began. I'll speak of actual cost in later in my post. I am a school teacher but have been involved in the construction of 3-4 stick built homes as well. I had a crew set up the exterior sips and I did the internal framing. I went with conventional trusses for the roof and I wish I had done sips there as well. I have a feeling like I am loosing some energy through the roof where blown cellulose just can't create that solid barrier.
I ran all of the electrical for the house and running wire wasn't too bad. A little tricky in some spots but overall no big deal. This is the second winter that we've been in our house and in mid Michigan it was a real bear. We have a 300 gallon propane tank. Filled it once in October, once at the end of December, half full at the end of January, and then another partial fill at the beginning of March. Maybe a total of 900 gallons. We also have a 13 SEER heat pump unit but it was too cold to run at all for most of this winter. It's funny to hear the propane guys amazement at our small propane tank and the amount of fuel we use. Our neighbors have filled a 500 gallon tank at least three times and their house is only about 2000 sq ft.
As for construction cost, I ran the numbers on that and for a 2x6 stud wall with 1 inch foam board on the outside and spray in foam, the stick build was just a bit cheaper......BUT with SIPs you do not have to purchase additional OSB, insulation, the walls go up so fast, not to mention NO THERMAL BRIDGE OF LUMBER. That last one is the kicker for me. In stick built, every 16-24 inches you have virtually no insulation. All together we spent about $205,000 on our 2800 sq ft house. Granted we did a ton of the work ourselves, and are still finishing as we go, but the overall structure is great.
In hindsight I wish I would have gone for the SIP roof panels and a higher efficiency heat pump, but overall, I love telling people about our house.
I'm actually seriously considering building energy efficient homes for people in the area. It seems like a no-brainer. My in laws are planning on starting a new home in the next year and they have agreed to be my guinea pig. Best of luck

Have you done a blower door test? Did you insulate the basement walls & floor? Seal the sill and rim joist area? How did you air seal the attic? Sounds like a good house for the money, but there is more heat loss than I would expect.