Well I have been searching around a lot here, and also talking with 2 local ICF contractors on some rough estimates.  The house design is a craftsman style ranch, about 2000sqft floor area, approx. 206 lin. feet with full basement, ICF all the way to the trusses.  9' walls, 8" basement with 6" above grade.  Nothing too crazy, about 12 corners.  garage would be stick. 
I got a quote for roughly $37,000 for the basement including 4" slab, drainage, gravel, etc, then about 27,000 for the above grade part.  I am talking with another guy who I am fairly sure will come in a good 10k total less then this one, plus he has an option for me to work with him, and he would cut his labor charges in half.  He would start the first row or 2, get everything all set, train and instruct us, then we build it up.  He inspects it before the pour and then does the pour.  We would save around 7000 if we did this additionally.

Here is my question.  As I was working on the house plans last night, I asked my wife about a 2 story option since we just were not liking the curb appeal the single story was giving us.  I have started to explore designing 2 story options.  My question is this:

Typically, 2 story costs less per sqft to construct due to less roofing and foundation.  However being as my exterior wall linear footage actually increases, how does 2 story construction price out with ICF pricing?  From a quick design, looks like my footprint will be reduced to 140 lin. feet, however that is now x3, making it actually 420 total instead of 412.  But I also realize the basement savings is greater due to the thicker walls, poured floor, drainage, gravel, etc is all less.  I would have to see if my savings in roofing and site work can also help that.  I also assume HVAC ducting cost would be increased.  We are planning on using a geothermal system.

Any insight would be great.

Can you clarify a bit.  Are you saying you have a linear footage for each floor?  You might be better off looking at it from the perspective of linear feet x height.   Regards.

tzerarc,

From what I normally see, many ICF installers (for the ICF part), sqft of wall costs are sqft of wall costs, so for sake of arguement if sqft of wall price is $11.00 and your wall area goes up by 1000 sqft, then the price would go up $11000.00. For the pricing you are being given, it is slightly harder to give an exact answer. Perhaps if things were broken down a bit more, more insight could be given by me.

One thing I would look at is the geothermal and its cost (of course after the tax deduction). If you are going all the way up with ICF, then you could be money ahead to go with a conventional HVAC. If lets say the cost difference between the two is like $10,000 then the rate of return will probably be quite long.



Not knowing where you are

Sorry, I will try to hit on some of the questions.

Option A:  Ranch style, 2000 sqft floor space on each level, 9' high walls on each level.  Linear ft would be 206' on each, making a grade total of 412 lin ft.

Option B:  2 story options, roughly 1300 sqft x 3 levels (basement, main, upper).  Approx. linear ft of each level would be 140' (x3) giving me 420 lin. ft.

For the pricing, if you break it out, the first estimate works out to be $14.50 lin. ft for the main floor and 19.50 for the basement (however basement included floor, not just walls).  seems high compared to a more typical 11-12.

The 2nd ICFer, who seems more willing to work with me, said to use 11 as a ballpark, however his price will be different/better he claims depending on a few factors. 

For the geo, we will be comparing the price of that system with a 95% efficient gas system.  My engineer consultants can design based on the construction and size the systems that way, correctly.  I am talking with some geo installers in the area and they are working up some budget numbers I can look at.

From what I have discussed with my engineers is, the 95% system can be sized down slightly, they thought a savings of 500-1000 tops overall by using ICF. 
Duct work for each system would be unchanged obviously.

For the geo, ICF has additional benefits.  Not only can the unit be sized down (although not by much), the biggest savings is in the wells.  If using an ICF basement, at 2000sf, most wells in our area can handle roughly 1000 sqft, costing around $2000 each well.  They felt confident 1 well could handle the basement instead of 2, savings of 2k right there.  They also thought the remaining house could be sized savings of roughly 1/3.  Meaning I would be looking at possibly 3 wells total instead of 4 or 5.  These savings, mixed with 30% tax credit, MIGHT get the geo system within a few K of a 95% system.   If that is the case, it is something a definitely want to do.  It just feels "right", especially in my profession. 
Besides, efficient and green design shouldn't just stop in some areas.  Why put in a less efficient system just because your building system is better?

Oh, and located in north eastern Iowa, with 80% relative humidty and 90+ degrees during the summer, and downwards for -10 plus windchill in the winter.  110 degree temp difference I have to design for.  Thermal mass is huge.  Not to mention tornados.  Sirens gone off 2 times in the last 2 weeks!  Plus, great soils and high/reliable water tables make geo a fairly affordable option around here.

Respecfully - for a multitude of reasons, you would be better off talking cost per square foot and getting away from cost per linear foot. It can be done but based on your post you are mixing the two and you and your installer are not talking the same language. When he says $11 he's talking about per square foot. Also, it does not appear you have taken into account the space between the floors unless you actually do not have 9' celings.


From above "Option A: Ranch style, 2000 sqft floor space on each level, 9' high walls on each level. Linear ft would be 206' on each, making a grade total of 412 lin ft."

------------------------- Consider -- Option A is 206 linear feet x 18' foot walls or 3708 square foot of walls. But actually -- if you want 9' walls you will need to allow for the floor trusses and this will require exterior ICF also -- If you want 9' ceilings then you are likely talking about 206 linear feet x 18' + 2' or approximately 4120 square feet --- and at $11 per square foot that's approximately $45K.


From above: "Option B: 2 story options, roughly 1300 sqft x 3 levels (basement, main, upper). Approx. linear ft of each level would be 140' (x3) giving me 420 lin. ft."


------------------------ Consider: Option B: is 140 linear feet x ( 9' + 2' + 9' + 2' + 9') = 140 linear feet x 31 = 4340 square feet or at $11 per square foot that's about $48K.

Just to add a thought about the geo. 1st - regardless of type you will need to properly size your AC tonnage. Ultimately this will equate to about one well per tonne here in Texas. Most AC guys will tend to overtonne an ICF house. In fact overtonning is one of the few problems i've had with ICF. Occasionally, I'll hear about someone who believes they've undertonned and then i find out that they built their roof/attic conventionally - (using BAT insulation) which i call a screen door on a submarine. Like Ren, I don't know where you are located. However, here in TExas it is fairly easy to get a house in the 1000 sq. per tonne arena -- most houses conventional are 450-550 square feet per tonne typically depending on windows and etc.  If I had my house to do over again I would go with (2000 square feet per tonne) and zone upstairs and downstairs. My house AC uses 1.6 cents per square foot per month.  Since the upstairs unit runs in the summer and the downstairs unit runs in the winter - i stands to reason that they might be the same unit.  Regards.

Sorry, re reading my post I can see how you think I am confusing lin. with the $11 sqft of wall.  I am throwing the 2 terms around.  In my head, I have them straight and they make sense.  However I did not type them clearly.  All of my dollar amounts are based on a wall sqft, I just convert it to lin ft. as it is easier to get a quicker price for me :)

For the floor spaces, I have not taken into account for the space between level 1 and 2 yet, but do realize that needs done.  I have not because I have not designed a 2nd floor option just yet.  However for the basement and single level option, we would most likely go with 8' ceilings in the basement with 9' above.  This should be able to keep both walls around 9'.  I should be able to use 12" deep floor trusses based on my basement wall layout for supports across the spans. 

Talking with a geo person just moments ago, it sounds like a 2nd level option would prove to be quite a bit more expensive then a single level option.  He says what he likes to do is have 2 separate smaller units instead of 1 larger zoned unit.  He said the more simplified duct running and calculations works itself out compared to one larger unit with zoning.  Plus it is easier to control.  This the added cost of geo and ICF, I do not think a 2 story option would be the way to go from what I have been finding out, unless I can come up with a footprint that can reduce wall sqftage.

Also, maybe you did not see it, my last post I posted my location.

tzerarc,

Sounds like you've made a plan, but TexasICF does know his stuff. As for the wall area, throwing around $11.00 or so a sqft of wall area can normally work without seeing plans. Some can argue otherwise, but that's' where those numbers came from. If you are working with a professional and putting in your own sweat equity, then that could certainly change the labor numbers. Just make sure the math doesn't get away from you (or surprise you).

Being admitedly biased, I would go ICF, especially if you are in the midwest and there are threats of a tornado. If the geo works (and soil is good for it), then that probably makes sense. That said an ICF ranch with a convention HVAC will not cost much at all on monthly basis either, so the split between the two could be minimal. May want an energy analysis of them both.

Best of luck none the less!

I am bumping this thread back up. I am getting deeper into our house design, and I THINK I have since ruled out ICF construction vs other options such as SIPs, or better yet, my own framing of double stud walls.
However I realize the other benefits of ICF, but I am not sure if the price can justify it. We will see though. If I use the $11 sqft number the guy originally quoted me, that works out to be around $16,000 for the upper walls and the same for the lower walls. However I can not see how this can be possible, especially based off of the first quote. He is suppose to be working me up an exact quote, so we will see how it goes. If I help him, he said he would charge half labor (he charges 4.75 sqft) so that drops the price to closer to $13,000.

In comparison, SIPs are coming in at about $12,000 for material, then me installing. However matierals for a double stud wall system are coming in at around $3500....HUGE difference.

Are you forgetting about the tornadoes you mentioned? IMO...if I lived where there are tornadoes every year..ICF only!

To date, I have not talked to one person that built with ICF's and regretted the decision.
Like robinnc said, tornado resistance is a big thing along with energy efficiency, sound resistance, fire resistance, and the overall comfort you cannot get from 2x construction.
Have you ever visited an ICF house, maybe even during the winter, or talked to many people that live in ICF houses?
Please keep us informed. We would like to hear your conclusion.

Posted By dwangle on 19 Oct 2010 06:24 PM
To date, I have not talked to one person that built with ICF's and regretted the decision.

I've come close, but I think that may be entirely because of the additional cost combined with a 30% drop in assessed value from the time of construction loan to mortgage closing at completion due to the housing market collapse.

What I more likely regret is simply building at this time, not building with ICF. It's a super comfortable, quiet, clean, house.