I like the idea of a nice solid concrete wall that you get from an ICF and I like the idea of the thick layer of insulation you get with a SIP. Obviously both can do a good job reducing air infiltration which can account for a lot of energy loss. Does anyone have a link to research that shows energy use for two similarly sized houses with one using ICF and another using SIPs? Anyone with building experience enough to be able to say one would cost X% more?

I look forward to this discussion...

A Previous GreenBuildingTalk Discussion

to be able to say one would cost X% more?

About the most anyone could say is what SHOULD cost more or less. Building skills vary so widely, I just haven't seen much consistency in terms of price for finished product. I have seen enough proper ICF to say that it should not cost more than 10% more than sticks and could cost about the same, depending on design, etc. Maybe someone knows similar for SIPS.

Some more links about SIP versus ICF…

Green Building Advisor Discussion

Grand County SIPS

ICF Builder Magazine

We often build custom homes in relatively remote rural areas that are prone to floods and wildfire. We prefer ICF for walls and SIP for simple roof designs. If we did tract homes, we likely would use SIP for both.

I don’t have a definitive answer for you ICF, but I will offer you my perspective and thoughts…

The material cost of both ICF and SIP products has to be much lower than wood studs. The labor cost to install SIP is much less than ICF or stick framing. So one might expect installed SIP to cost less than installed ICF, and BOTH to cost less than stick framing. However, I think both ICF and SIP products are sold based on “value pricing” and not on margin above manufactured cost. Value pricing is essentially what a manufacture can obtain for their product given the other products that they are competing against.

I would have thought that the Chinese would have entered the US market by now with ICF and SIP products offered at way lower cost than the current prices we are paying. I suspect the reason they have not done so is because ICF and SIP products take up a lot of volume and the resulting shipping costs likely don’t make this business model as competitive as it otherwise would be. Now if a Chinese company setup camp to accomplish the manufacturing and shipping within the US, and could cheaply ship the raw product materials to their US manufacturing facility, I think you would see ICF and SIP products offered at way lower cost than the current prices we are paying. There would initially still be GCs charging more for the installed products than the job is worth just like today, but competition and saavy consumers might eventually mitigate some of this too. So it is currently all about supply and demand...and the future will be all about supply and demand too...

Posted By sailawayrb on 26 Feb 2014 11:33 AM
I look forward to this discussion...

A Previous GreenBuildingTalk Discussion

That's an eye opener. Almost makes me want to crawl back to a stick house. I know this is a very general question and can only be answered in generalities. I want to go to the architect or builder with as much information in hand as possible. Knowing one wants to build a house this way or that so as to give direction to your dreams is what I am after. Every wants a green energy efficient house but the road to get there varies. My basic plan is a 3 bed 2 bath house around 1600 sq ft main floor plus a full walk out basement with all the mechanicals down there. I want to keep it simple but still have a great house with low energy use, low wall penetrations, etc. As a home owner you may only build a house a few times in your life so you really want to do it right the first time.

Posted By sailawayrb on 26 Feb 2014 03:14 PM

The material cost of both ICF and SIP products has to be much lower than wood studs. The labor cost to install SIP is much less than ICF or stick framing. So one might expect installed SIP to cost less than installed ICF, and BOTH to cost less than stick framing. However, I think both ICF and SIP products are sold based on “value pricing” and not on margin above manufactured cost. Value pricing is essentially what a manufacture can obtain for their product given the other products that they are competing against.

...snip...

Both ICF and SIPS use EPS rigid foam for insulation, while wood stud homes can use cellulose or fiberglass, both of which are much less expensive per unit R-value than EPS. That would seem to be one reason that stick-built homes are typically less expensive than the other two approaches.

Posted By okarrow on 26 Feb 2014 03:01 PM
Some general cost comparison info (not vs ICF) but you may find it helpful.

http://hi-techbuilding.com/wp-conte...s-wood.pdf

http://starcraftcustombuilders.com/sip.htm

If you use SIPs do not use OSB, use the steel SIPs aka the SSIP.

Helpful - thanks!

I am certain that you meant to say an attractive, capable, and intelligent woman demonstrating how to properly install SIP...

I want to go to the architect or builder with as much information in hand as possible

An architect who knows SIPS or ICF is key. DON'T go to one who hasn't done it before. Same thing pretty much applies to the builder.

…and also applies to your engineer, should you need one to address some required design issue (e.g., seismic, lateral wind loads from large passive solar roof overhang, etc).

…and also applies to your engineer, should you need one to address some required design issue

Their software packages seem pretty flexible, although you may have to show them how to get it off of some default setting they have always used.

Unlike in Europe (at least in the past when my dad was an architect working in Munich Germany in 1970s), architects in the US are typically NOT also engineers and they typically can NOT approve building design issues requiring structural design analysis and buyoff. Architects typically focus on building layout and aesthetics…which is very important…but also very different than structural design analysis and buyoff. It is also true that some building authorities will mistakenly approve an architectural plan that has some design issue that SHOULD have first received structural design analysis and buyoff, but did not.  This can make for some very interesting "lessons learned".

SIPs are very easy to install and I think that may create the misconception of comparing them with traditional building materials and construction methods. The design and engineering are the very first part of the process. The SIPs are then made to those specifications and delivered to the site. The specification submitted to the SIP manufacture will be checked, re-checked, reviewed, and finally approved. This is a critical part of the process and one the reasons it’s important to rely on a trusted manufacture and distributer. They will all be sized and cut to your spec which includes window and door openings, utility pathways, angles, etc. The only thing installer does is install – no cuts or modification required on site. Additionally, a building system is required to connect the SIPs together. Like the SIP, the building system will vary by manufacture but all necessary hardware should be included. You can buy different brands of traditional building materials and for the most part it will be same or at least similar. SIPs are not traditional building materials and different manufactures use different SIP composites, and building systems, they all have different ways of doing things. Long story short when planning SIP construction use a trusted manufacture and distributer. The manufacture and distributer will have their own designers and engineers which can greatly help with the process but that assistance and quality of it will vary greatly among different manufactures.

I was really on the fence about SIP's versus ICF. I ultimately went ICF, since my basement was going to be ICF anyway, and the system was easier for one old man working alone. If you go SIP's, go steel skin, as someone else mentioned. I think either one will produce a solid, energy efficient house.

Isn't concrete really expensive, though? I would think that sips, though expensive, are much cheaper than pouring that much concrete.

Around here, a cubic yard of concrete suitable for pouring ICF walls costs ~$100 delivered. That yard of concrete will fill 54 sq ft of 6" ICF forms, so my cost for concrete is ~$2/sq ft. My total cost for ICF wall materials (forms, rebar, concrete, etc) was ~$6/sq ft. How much does a 6" SIP wall panel cost per sq ft? How much is the strength and quiet of concret walls worth to you?