So I need an opinion from some folks on here: I am planning on building a 2 story (above ground) house with about 3500 sq. ft. above ground with a full walkout basement which will be about 1200 sq. ft. unfinished (in addition to the above ground sq. ft.) I am building about 30 miles west of Minneapolis, Minnesota. At the recommendation of another professional, I was planning on building with an ICF foundation/basement (below ground), using SIP’s for the above ground walls with raised heel trusses for the roof. Doing it this way (as opposed to an all ICF home) is a cost saving measure. Has anyone out there built like this and have any soundly based opinions on this?

I've seen this done and it can produce a great home. I deal with icf's but if I lived where there are not tornadoes or hurricanes sips would be an equally great choice. I think sips and icf can pair great, but more so with icf walls and a sips roof. I've heard some builders in my area state that they can do the icf basement/sip main floor cheaper than all icf but it's yet to turn out that way. The cost on the 3 I have seen has been a wash and taken a few days longer than just icf. However that could very well be builder related but all 3 were very familier with both technologies. Whatever combo you do, both sips and icf are far superior to typical stick homes and you will no doubt be happy. In my OPINION, I would just use icf all the way. MY experience is that it's easier and faster. Whatever you decide you are headed down the road to a great home.

Are you planning on doing any of the work yourself?

It is interesting how each of us have different experiences with construction. I build with ICFs below grade and SIPS above grade because it IS far less expensive and faster than using straight ICFs. Typically, our ICF cost are 2 times our SIPS costs. And above grade, with lots of window and door openings, the difference is greater. Also, I only use SIPS for roof systems on relatively simple roof designs. The more complicated roof designs cost so much more for labor and engineering, that I use traditional trussed systems and spray foam on the underside of the roof decking. This works well for our area, and types of construction. Topace 4, I believe that what you have planned will work well, it certainly does for us.

We have designed many homes with this concept:  Icf foundation, sip walls and trussed roof systems.  It is the most practical way to build but as others have said it depends on your roof system and complexity of your walls.  My first choice would be to build icf foundation with sip walls and roof but only if your roof is straight forward.  We have talked many a client out of sip roof systems due to the end cost and  actural value.  Most sip suppliers can do it but is it in the best interest of the client or are they just trying to sell it to the client? You can waste thousands ($) in a roof system and it will do nothing for the floor plan.  We first look at the client needs, whats practical, budget, etc. and then design the home.  No sense designing a home that you can't build or afford to live in!
Have a great 2010!

Since I'm new to this bulding thing (and this forum), what is a reasonable cost for SIP's in the upper midwest area?

There are many parts to a sip project: screws, sip tape (with roof) cutouts, sealant, etc. So giving a cost per square foot does not tell the whole story. In Michigan we sell 6 5/8" wall panels at $3.47 sq. ft. or less depending on quantity and 10 3/8" roof panels at $4.26 sq. ft. The best way to get prices is to send a sketch so you get the whole picture.

pdk - sent you a private message on this topic....

2 TIMES AS EXPENSIVE? Then you need to do some serious rethinking of your icf costs because you are getting robbed somewhere down the line. A hybrid house can be a good home, but to make a claim like above is absurd. 2, 3 or even 5% difference is the norm varying by builder as to which is more expensive. Sometimes it's icf sometimes it's sips.

Hey PDK, (if I may hijack this thread for a second) What type of waterproofing do you utilize with your sip roofs? We have found that when an icf house gets a roof (sip or otherwise), the peel and stick icf waterproof membrane is an outstanding option for sealing windows, doors and doing an all over ice dam of sorts. We offer it as an option and so far a lot of people take us up on it. Have you ever done that before? THX!

In Michigan we have to use Ice and Water Shield 36" up the roof past the interior wall line. We of course do the over hang as well and all valleys. Depending on how you "frame" your sip roof systems I would or would not seal the ridge line. I say this because if you are using framing members in the sip panels in a heated area your ridge line may or may not have to breathe. I did not say vent but breathe. The homes I built in the 80's are now having some issues with the ridge line and the top osb deteriorating (ridge rot) due to the fact interior moisture was finding the path of least resistance which are the framing members in any roof system. I have since gone back and installed ridge vent to dissipate the moisture in the older homes. Newer designed homes and technology appears to take care of this issue now. Ventilate right is always the rule when building a super tight home. Sorry for the long answer but I would like to prevent any new builders from making the same mistakes like we did in the 80's .

You make a valid point, and I failed to mention that we almost exclusively spray foam the underside of the deck now a days for insulation and vapor RETARDER. We have found that this combined with a "waterproof" roof before shingles (or whatever) go on, has proven to be wonderful insurance without substantial cost IF there is proper erv/hrv added and I can't stress that enough. It's an option we can do and I'll admit it could be considered overkill; I'm ok with a little overkill. lol While I may need to make my own thread on the issue of air tightness, (sorry topace) my quick answer is that I agree that ventilating RIGHT is key, especially with how tight an icf or sip home can (should) be. My goal is to rely totally on the erv/hrv. it's the houses snorkel. :) Our hvac guy is quite good with mapping out the needs of a super tight home and does the proper calculations to ensure safety, moisture control and comfort. I like to pretend a biological attack is going to hit this home and I have to prevent anything from getting in. lol I go through a lot of caulk and spray foam as I consider that cheap insurance and the owner of the home will benefit in the long run. Thanks for the quick reply!

Rykertest, You know, I have a pretty fair idea of what my costs are for ICF and SIP construction. These costs vary from project to project, but not by any great amount. My statement of cost comparison above is fairly accurate for my particular circumstances. My actual costs PSF of ICF walls are generally below the average costs quoted on this forum, so I don't think I am overpaying for ICFs. Maybe you are overpaying for your SIPS? By the way, in 15+ years of building with SIPS/ICFS, I have never seen the prices being comparable.

Wes,

Would there be any way that you could share the average prices you are paying for ICF's and SIP's, just so I can get a ballpark?

if you're willing to share, I'd be interested too.  Specifically, I'm curious what you average per square foot of wall/roof area, including labor.

This may just be a regional difference, we really have no way of knowing for sure. I've done the research for icf and sips and landed on the icf side for numerous reasons, most of which are obvious or not pertinant to this thread. My experience is that SIPS cost more for product (extensive work in 4 states) , and I've checked in a few others states as well as the west cost for price comparison. In some places they run neck and neck, in other places one will cost substantially less than the other, and the third option (which is becoming more and more polular) is they team up and provide a icf house and sips roof package. I don't generally use sips because they have proven to be chronically more expensive by varying margins but nothing like double.

The cost variation could be because one of us reps for one product or is a dealer and just uses the other product. There might only be one company of either that is in a certain region and he "owns" the market on one or the other and can charge what he wants. 5 icf companies and 1 sip company, who do you think is gonna offer the better deal? There could be price differences due to brand of icf or sip, there could also be a shortage of qualified labor. I've had some crews want to charge more for drywall in an icf house because they said it's harder to do. In fact it's easier to do and faster for them but they don't know icf, it's new to them so they want to charge more. I say all this because I recognize that there are a ton of variables that can affect price. However, DOUBLE is (at least in my opinion) way to much to be considered a variable; something is wrong. If you lived in California, then I would say double the price is a good deal, lol, but not from MO to KY. Just because you have not seen it doesn't mean it's not out there or that it's somehow rare; this isn't like looking for an honest politician. I routinly check prices with competitors and that includes sip guys to see how the prices have shifted. Sips land on the more expensive side about 90% of the time in the regions mentioned above to varying degrees. If ICF's were truely double the cost of sips, nobody but the ubber rich would build with them and the industry would be a niche at best. Prices with a 10-15, or even 20% difference...ok.. but DOUBLE.....nope, I just don't buy it. Like I said, I don't doubt that a hybrid home would be a good home and I would be happy to live in one as it is far superior to a stick built home, but the price difference between icf and sips you quoted is seriously skewed.

In addition Wes, before we go any further, I'm not trying to pick a fight here or insult you and if I did then I extend my apologies.

It has been my experience that the better SIPs are usually more expensive than the typical ICF. I am saying better SIPs because a SIP can vary from one that provides characteristics similar to ICF to one that provides characteristics that are closer in performance to a 2x4 framed wall filled with foam. Lower end SIPs (or poorly designed SIPs regardless of price) allow conduction from one surface of the wall to another via wood or steel members. This characteristic is never present in a better SIP. Keeping the structural members from transferring heat through the wall is what (in my opinion) defines a better SIP.

I say typcial ICF because some ICFs are more labor intensive than others but in the end-game - that is once you move into the structure they will perform with similar thermal characteristics. Due to variety this is not always the case with SIPs. By the same token, ICFs that are on the low end may cost as quite a bit more to install. You can go down to Home Depot and buy some foam and make up your own ICF as well. This is why you are better off an installed price instead of block price. I suppose this is true for SIPs as well.

One thing is definate here in Texas, the SIPs guys have successfully convinced many that even though ICFs are great they are quite a bit more expensive than SIPs. ??? This may be because may SIPs consider ICFs their competition (based on their websites). Yet I haven't seen a single ICF site that talks much about SIPs. In my opinion, SIPs and ICFs should collectively go after the stick market since it still the inferior king of the hill.