I'm building a 2400 square foot ranch home and have found ICF vs traditonal to be about 18K more, which seems high based on all information I'm finding out there. I was given a price of 45,700 to do a traditional foundation with 2x6 walls, ultrafit insulation, this price includes foundation, waterproofing, 9ft basement walls, excavation, basement floor, and garage floor. If I compare that to my lowest ICF block quote for the same items the quote is around 63,500. The biggest discrpancy is the foundation part of the figures. My tradiational foundation was quoted at 28,700 compared to the same items in ICF foundation I'm about 15K more. I'm only getting about a 5K discrepancy in the upper level figures 2x6 walls replace with ICF.

What I'm asking here has anyone put ICF ontop of a traditional foundation. My thoughts were a 10" traditional wall with 6" ICF 2" of foam outside and inside. My only questions are about if this is possible without a bunch of problems and how do you deal with brickledge and floor system attachments? Let me know your thoughts.

I was not expecting this much discrepancy between the quotes. I figured ICF might be about 10K more, but not 20K more.

Thanks.

Where are you located?

Are both estimates equal to each other? 

Do both the ICF and regular basement wall bids include Waterproofing?

Do you have a square footage of wall for the basement?

Initial thought is that the ICF is being priced too high, perhaps due to inexperience? 

Yes, you can install the ICF on top of a traditional concrete basement wall.  There are a myriad of methods for the floor system attachment and brickledge details, I would suggest you talk with a technical salesperson at the ICF product company that you are considering to use.

With what little information you have already provided, I would suggest that the only increases in costs should be the cost of the ICF form and possibly a better quality waterproofing vs. that of your conventional basement walls.  There should however be a deduction for the labor and materials to make the conventional basement equal to the ICF basement wall in terms of stud walls and insulation as well as possibly a reduction on the labor to install ICF vs. that of other methods...concrete and reinforcing steel should be the same.  Either way, you are still comparing two systems with performance characteristics that are on opposite sides of the spectrum.

We poured an ICF home on top of a traditional foundation. The foundation was 10" and we used the 11" Reward block. We held the ICF flush to the inside and over hung 1" on the outside. To attach the ledger board we used the simpson ICFVL imbed.

My tradiational foundation was quoted at 28,700 compared to the same items in ICF foundation I'm about 15K more

Something is not quite right here (as you know). The numbers should be close. Apparently, you are in a area where there is quite a bit of competition for traditional foundations (it that poured in place?? or CMU??) because in many areas the ICF is less. I would ask a few more questions before putting more of a house on less of a foundation.

Your 2x6 numbers appear to be closer -- does this include insulation foam, tyvek, plywood, additional AC tonnage required etc. etc?

Thanks for all the posts. Allow me to try to address each one with a response.

atitagain: I'm located near cincinnati, oh, both estimates are equal comparison wise except the ICF estimate did not include escavation as the traditional foundation quote did. Both bids did include waterproffing. Basement wall square footage is around 2,000. I've priced several ICF installers in the area and this pricing has been the best I could do thus far.

texasICF: the foundation is a traditional poured wall foundation and yes I think that may be part of the problem is that this area must be competitive in traditional foundations. The 2x6 numbers are closer and yes those figures included insulation, huber zip system walls and additional HVAC tonage was not factored, but after talking to HVAC guy is nominal to upgrade to larger. Perhaps 1K or less.

Part of the problem with my ICF bid I think was an overestimate of total wall square footage and very high priced footer. I'm still waiting on a couple other bid prospects for this project and am hopeful we can close the gap. I'd much rather build full blown ICF instead of a hybrid setup. Does anyone out there feel a traditonal build can even come close to the energy efficiencies of ICF? We are just so tight on our budget at this point that 5-10K makes a huge difference in the big picture. I just don't want regrets after building since this is our "dream" home and plan to live in it for the rest of our lives.

kschweitzer, plenty of people out there "feel" that they can build traditional to the levels of ICF but they are wrong. As soon as one tries he's not traditional anymore and the harder one tries the more the system starts to resemble ICF. What exactly is your HVAC guy saying? It has been my experience (in Texas) that (when ICF is coupled with a good roof system such as foam or SIPs that the tonnage is often 1/2 that of conventional construction. To get accurate numbers including house orientatino and windows and etc. etc. you might contact Richard Rue of energy wise structures. Regards.