This was a big month for us. Our plans got past the Planning Department with no changes, we narrowed down the options for our power generation, and last but not least I've selected my ICF supplier.
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I would imagine I spent way too much time on this, analyzing the various products that we'd sent out bids for. There was a lot of "back and forth" between myself, my contractor, and the various suppliers as well--I learned all kinds of things I never knew about settling, reversing blocks, R-values, etc. I finally, (like most folks here I suspect) built myself a fancy spreadsheet to hold all the information I had; when a particular element was missing from a given supplier (for example, the Greenblock guys didn't give me a concrete estimate), I averaged the values I got from everybody else and plugged those in instead. I then added the numbers that seemed to be missing (such as nobody saying I'd need any of that fancy-expensive spray foam stuff when I know I'll probably need it around the V-bucks and special cuts) and took a look at the bottom lines. Then, just for good measure, I divided the R-value of each system into its estimated cost to get (effectively) a "dollar cost per point of R-value" measure.
Imagine my surprise when I discovered that, on balance, there wasn't all that much difference in price between the various systems.
Oh there was some, to be sure, and it was more evident when I used the $$$ per R-value measure. The various systems (I compared seven) broke out three rough groupings of "high" to "low"; though to be fair, the high value and the low value were only $764 apart. Looking at bottom-line cost they varied from ~ $87K to ~$105K (this is for the walls, floors, rebar, foam, concrete and concrete trucks, bracing, V-buck, etc.). This seems more significant than it is, given that all concrete estimates were purely estimates only--there's really no good way to tell until the day you place the concrete order.
I also kicked around the various system differences. As systems, the seven broke into two main categories--those that used a "tongue and groove" connection system between blocks and those that used a "Lego-like" interface. I decided after much research that the "steel vs. plastic" issue (where most systems use plastic webbing and a few use steel) was basically a wash--while there used to be issues with thermal bridging with the steel systems, they'd rectified that years ago and the newer studies didn't indicate any issues.
So after I built this spreadsheet and fiddled with the numbers, I gave myself two weeks to let it simmer--and then I selected Buildblock for our ICFs. I like their Lego-style connection system, I like the more closely-spaced webbing their blocks have than most systems, I like their plethora of measuring marks on the forms themselves (which makes cuts much simpler), I like the fact that the shipping is more efficient, I like the fact that they have a plant local to me, I like their prompt replies to my questions--in short, I just plain liked them more. Using the $$$-per-R-value measure they came in at the high end of the low group, which indicates good value. It just "feels" like it will be an easy product to work with. Last but not least, the couple of local O-Bs I'd talked to who built with this system had nothing but praise for it--that's a big plus in my book.
This was probably the single most significant decision I'd have to make since we're going to build this monster ourselves, so I wanted to make sure it was as easy as possible. There will be other hard ones (I don't look forward to picking out the windows) but this is the one that would probably annoy me most if I got it wrong. I think I made a good choice--at least I hope so!
Dang this is fun!