I am interested in the opinions of pros and cons regarding either a double wall (2x4) or modified larsen truss - 12" - Cellulose insulation design  compared to a Structural insulated panel 12" EPS design. . I am within 2 hours of a SIP supplier so transportation cost is minimized.

Both systems should give an R value greater than 40. Only considering wall construction and not roof.

I am concerned with the following:


Cost to build - builder buit not DIY - additional costs to trades particularly electrical and/or plumbing 

Sound transmission - near busy highway - any additional soundproofing measures negate cost savings?

Longevity? - is delamination a true issue 50 years out  ( homestead house)

Other issues not mentioned that would be a concern short and long term.


Thanks for any and all insight.

My father built a double 2x4 wall house on an ICF foundation. He later regretted it and wished he had done all ICFs.

Polycore, I don't know whether or not you noticed that Clancy mentioned that this is going to be a "builder built" project not a "dyi" That point alone should favor the use of SIPs over the "DFW" approach in regard to costs.

I've tried to reinforce this concept in several posts to previous threads in this forum, along with the many other benefits, and "green" advantages of SIPs over the "DFW". I think that the other issues in connection with SIPs are all pretty much "moot" if the "professional team" is experienced and reliable, eg: architect/designer, engineer (if applicable) manufacturer, fabricator, contractor, etc. Of course it will help if you can find a "sip experienced" contractor, and you will find many very capable, and some not so capable, "stick" framers, that will try to talk you out of SIPs, or even refuse to work with them. Then there are the ones who will agree to work with the system but want to charge the same, or more than if they were "stick framing" the same house. Quite often this latter group is interested in learning the technology but, as I put it, "they want their client to pay their tuition" However, these comments typically apply to standard stick framing, not a double wall with all of the additional labor and materials.

While I'm at it, I'll throw in my usual plug "Also consider usling SIPs for your roof "

In any event, Clancy, good luck with your project, and your search to find "the best possible building system for your project". After all, that's what this is all about isn't it?

Neither Sips or a double 2x4 wall is as strong, mold free or quiet as ICFs.

I'm in complete agreement with your last post, ICFconstruction.........However, ....... yada, yada, yada..................................................

(I just deleted a lengthy reply regarding, individual budgets, site conditions, availability of materials, labor considerations, etc etc etc) All of this has been hashed, re-hashed, and then some, within the forums on GBT. I would suggest that, as others have suggested from time to time, that you new visitors to this site can discover a wealth of information by exploring previous posts. Some of you may not realize that you can search for threads that are applicable to your particular questions. I guess that I need to add that I'm aware that not every new visitor this site has a question as many have information to enlighten and educate. However, this group might find the the vast archives of postings to this website to be "interesting" also.

Now, having said that, if you (new visitors) do take this advice to heart, you should probably be an experienced "Wheat from the chaff separator", and, even then, one could get a bit confused sometimes. If that does happen, just "come on back", and us "pros" will do what we can to clarify things for you. (Won't we guys?)

You must be thinking of OSB SIPS   ;)

i have posted this in another thread, but here you go,

for our upcoming project, we were set with sips for a long time. after doing a lot of research and comparisons, we ditched the idea and are going with stick framing, however little differently. here is what we are doing:
1) we are going to use double 2x4 walls with staggered studs with 2x8 sill and top plates. this will eliminate any thermal bridging in the walls and corners. with sips, you can use insulated connector pieces instead of dimensional lumber but it is additional cost.
2) we will insulate first 2" of cavity with closed cell insulation, to seal the building envelope. this will give us R value of 14. rest of the cavity (5.25") will be filled with blown in wet cellulose, giving us r value of around 18, so together overall R value of this system is 32. same as exp core 8" thick sip panel, for about half the cost. if you are using insul connector in sips to avoid thermal bridging, than the difference is even bigger.
3) also you need to realize with using sips, you need to design around them. also wiring labor will be more expensive, and you have less flexibility down the road.
so my conclusion is that you can do same or even better performing system traditional way for about half the cost. also i didnt mention additional cost for delivering sips (local lumber yard will deliver dimensional lumber for free), sip drawings, equipment / lift for unloading and lifting sips.

i personally dont like either of these two systems really. i come rfom europe where we construct our homes from porous concrete blocks which give you r value of 30, which is code required minimum, also excellent sound attenuation, structural integrity, and feeling of security that you are really protected by solid mass instead of hollow wall. just knock on the wall of european house and american house and you will see what am i talking about.. also most of the european houses are additionally insulated to 50 r value. just finding out that here in us only r19 is required had me really laughed.

" i come rfom europe where we construct our homes from porous concrete blocks which give you r value of 30"

How do they make CMUs R30?

well, it is not cmu.
check out this link
http://www.xella.cz/html/czk/cz/YTONG%20LAMBDA.php

it is not in english but if you scroll down to the table, you will see that U value of Ytong lambda 500 block is 0.19. to convert to american R value u need to multiply U by 0.176 and than divide 1 by the result. you will get 29.9...

And I thought ICFs were "the way to go".

What are those blocks made of? I don't understand your math on figuring R value; R-value would be relative to the thickness (R-value per cm x thickness), not area.

reread my post, i messed up on converting.
block is made of porous concrete, same principle as closed cell foam, but implemented in concrete i would say.

Since you are worried about sound transmission, double walls are the obvious choice over SIPS. Properly constructed double walls are exactly what studios and theater buffs use to stop sound. With this type of wall you will be limited by your windows. Of course one option is to use SIP as the outer wall, but for sound transmission you would be better off putting your money into adding more mass to the outer leaf or inner leaf, e.g. by an extra layer of sheathing or drywall. Larsen trusses also lose to traditional double wall since they lack the decoupling necessary to achieve sound isolation. One lower cost option to consider would be to use staggered studs like shown here: http://www.greengluecompany.com/wallTypes.php.

A staggered stud wall should be cheaper to construct, allow plenty of room for insulation, and good enough to make your windows and door the weakest link. I think it could be a pain to insulate tightly with batts though. I'm going with double wall for my house, but I'm also floating the ceiling to stop sound between floors. Otherwise it would be tempting to use staggered studs and blow the walls full of cellulose.

So what is the r-value of it? How strong is it? Is there nothing here like it?

as i wrote, for lambda 500 R is 29, that is their best product, they have also lambda 300 with R13. it is structural block, meaning that walls built out of it will support monolithic concrete floor/ceiling constructions. also as i am aware you can use it up to 6 floor high buildings. you canot find it here. same as you can not find stick framed houses in most of the europe.

if you were interested, here is another popular brand Porotherm, it is a clay based block with air cavities. Ytong Lambdas and Wienerberger Porotherm products are most popular building materials in my country. you can check out their website. it is in english.
http://www.wienerberger.com/servlet/Satellite?pagename=Wienerberger/Page/CallArticle05&cid=1122448619064&c=Page&sl=wb_com_home_en

ICFconstruction, brankulo is talking about autoclaved aerated concrete (also known as AAC - it's not the same as CMU). They add aluminum to the concrete which makes it foam up as it cures, then they bake it in an autoclave. The tolerances are extremely tight, so you can actually rely on the block measurements. It does have a high R value because of the entrapped air, and it is structural. Rebar can also be added. It is available in the US, but unfortunately it's use is not widespread. In the US termite food is the preferred material.

www.safecrete.com
http://www.xella-usa.com/html/us/en/index.php

i would be interested how does the price compare to the similar r value stick construction.

Also available in the Us is aerated cellular concrete which can be made to do everything AAC can but at a lower cost and with much more versitility.

Density of 2 PCF (R value of 3.9 per inch) to full density is achievable by just adjusting of the aeration.

AAC is fine if you live within shipping distance of a multimillion dollar facility and can live with all of the limitations in design.

Amazing how any thread, no matter how specifically the question is worded ( read the original post) can be "guided' by ICF contractors.