Well minimum charge for a pump truck alone is 4 hours, so $ 600-800 alone if it's a separate pour(which would be dictate by the height/pitch of the roof), plus block, minimal amount, plus concrete so figure $ 1200.00 minimum. What's a truss cost, $ 100 each +/-? Spray foam is irrelevant as I am saying only use gable truss if it is a flat ceiling inside. reinforcing is a variable, but lets say $ 200.00 in materials. Not that it's fair, but we will call the labor even. So rough guess minimum double if not 3 fold ICF over gable truss.

Don't get me wrong, I'm not discounting ICF here, I only stating that if it's not being used in a beneficial area, don't use it.

Posted By dmaceld on 18 Feb 2013 02:42 PM

Plain & simple, time and money, especially if you're not in a hurricane or tornado area, which is what, 70% of the country? From what I remember seeing of your drawings you've posted, and seeing the pics and drawings of what nd96 is building, it appears to me that cost is a secondary consideration for both of you. Keep in mind most ICF houses are built by guys who are going for the best they can on a tight budget. Why overbuild when ICF is plenty pricey as it is? Up north in Idaho, Montana, Minnesota, etc., you don't build a roof for high winds, you build it for high snow loads. There's a difference, a big one!

You build what makes sense for the location, and the budget.

Unfortunately I don't have a blank check policy, I wish I was in that position.

Here is how it plays out. You have a 100mph wind area with an "Exposure C" facing the gable. It is in a termite area with a moderate to severe forest fire risk area. To me it's ICF/concrete all the way or go home. The question of "overbuilding" is a reasonable one but here is how the logic plays out:

Why build a gable end with ICF when you can save a few bucks and stick frame it? Even though the ICF mantra is "why wood you?", I guess here is an exception to the rule. Why build with ICF? Why not just stick frame the thing? It's much cheaper and easier to stick frame. Why a nice architectural design?  Just make a rectangular box with some holes for windows. Boxes are easier & much cheaper to build and heat/cool. Why even build? One can buy a fully furnished 4-year old tract home for $50 a square foot out in my area. Even though it isn't extremely "energy efficient", who cares?  If I can buy a 2,000 sqft home for $100k, I can leave the stupid windows open and still be decades ahead on the ROI. What about embodied energy? The embodied energy of building new is always greater than just buying an already built home.

 Now, what was the question?

Posted By Chris Johnson on 18 Feb 2013 05:25 PM
Well minimum charge for a pump truck alone is 4 hours, so $ 600-800 alone if it's a separate pour(which would be dictate by the height/pitch of the roof), plus block, minimal amount, plus concrete so figure $ 1200.00 minimum. What's a truss cost, $ 100 each +/-? Spray foam is irrelevant as I am saying only use gable truss if it is a flat ceiling inside. reinforcing is a variable, but lets say $ 200.00 in materials. Not that it's fair, but we will call the labor even. So rough guess minimum double if not 3 fold ICF over gable truss.

Don't get me wrong, I'm not discounting ICF here, I only stating that if it's not being used in a beneficial area, don't use it.

The numbers seem off, where is the OSB sheathing for the stick frame, how about the exterior EPS foam for the wood gable end? OK, I will go with the numbers given. So $1,200 for an ICF gable vs. $200.00 for a stick frame gable that still needs to be sheathed and have 2" of exterior EPS applied. An initial $1,000 difference. Although I believe that number for wood frame is off/under by about $500.

If it's always about ROI, then the logical thing to do is DO NOT build a new custom home. It makes ZERO sense in both "green" terms and financial terms to build new when you can buy a built home for 1/3 of the cost.

I don't understand the reasoning behind it. I'm sorry because financially the argument falls flat. If one is arguing finances, then complete the argument and don't just stop with a gable end.  If the financial argument is completed, it brings you to the logical conclusion that building in ICF or wood frame are both wrong. Neither makes sense. If overbuilding is the argument, then whether it is a wood gable or concrete gable, are both irrelevant. ICF's purpose is all about overbuilding. The industry makes it's stand on it.

Basically the statement being made is: It's cheaper, easier and better to build it with stick frame and it's too complicated & overkill to do in ICF.

So why doesn't the above apply to the entire home then?

To go back to the OP question:

Posted By dford1 on 17 Feb 2013 09:07 PM
Is it cost effective to ICF all the way up to the roof line? My builder normal goes 9'6 then wood/spray foam...Fox Block 6 inch Phx, AZ. Thanks..

I'm not grasping the reinforced concrete wall, stopping at the rectangle and transitioning into wood frame at the triangle/gable because it saves $1k. I don't mean to upset anyone but the whole wood gable top on an ICF wall is just silly to me. If one is concerned about $1k and being cost effective, then you need to reevaluate building new and building with ICF.

your "passion" (ok lets call that) about ICF is utterly insane. Too many factors can be applied to random images that are 1 in a thousand. Who knows, 10 thousand? I agree with the arguement and numbers. I put a wood truss roof and gable ends on my ICF house. A gable end truss, correctly installed, can withstand very high winds. You can't slap it up and expect it to bear high winds. There are install guidelines. It needs braced back to the other trusses. A trussed house is an engineered solution, and commonly the strength as a whole comes from the components of the system linked together. Sure, the gable truss may be taking the brunt of the wind pressure, but its the roof assembly that is creating the overal shear plane for the roof diaphram. This assembly, like all things (including ICF) need to be installed correctly to function as it should.
Back to the numbers. Why would you add foam to the exterior of a gable truss? If you have foam below, then use furring to space out the siding. This is a typical detail I do all the time. My gable end truss aligns with my ICF wall, so the siding plane runs continuous as do most.
I agree with others...there is no real strong arguement, from a structural standpoint of correctly installed trusses, why a concrete end would be better than a wood gable end. It is $1000+ easily saved on a project that can be put to....better windows perhaps? (or something that actually does make a difference)

Something that actually does make a difference...

...something like the granite countertops, mayhaps? (It's for the thermal mass, benefit, right? ;-) )

What's the highest wind speed ever recorded in Phoenix?

http://www.azjerry.com/weather/wxwindsummary.php (Not much scary stuff there from a design point of view... )

I get that the snow-loads are pretty low there...

Unless it's a cathedralized ceiling/insulated roof deck there's no thermal performance advantage to an insulated gable end. There IS some advantage to air-sealing the inner EPS to the ceiling gypsum from the attic side with open cell foam though. There is also a significant thermal & comfort advantage to using mass walls in a Phoenix AZ climate if you do the window-SGHC & roof overhang/shading issues right. It takes a lot more thermal mass inside the walls to make up for it if you blow the windows & shading issues though. Spending the extra grand on a better windows (or better load management design) easily trumps a high-mass insulated gable on trussed roof attic where the insulation is at the truss chords rather than the roof deck.

If the roof deck is being insulated to deal with ducts & air handlers in the attic, there's still no particular advantage to high mass gables- it's too little mass, too isolated from the space to matter. High mass roofing would be a different story though.

Posted By Lbear on 18 Feb 2013 05:27 PM
Why build with ICF? Why not just stick frame the thing? It's much cheaper and easier to stick frame. Why a nice architectural design?  Just make a rectangular box with some holes for windows. Boxes are easier & much cheaper to build and heat/cool. Why even build? One can buy a fully furnished 4-year old tract home for $50 a square foot out in my area. Even though it isn't extremely "energy efficient", who cares?  If I can buy a 2,000 sqft home for $100k, I can leave the stupid windows open and still be decades ahead on the ROI. What about embodied energy? The embodied energy of building new is always greater than just buying an already built home.

Those are exactly some of the things that have gone through my mind these past four years after the market crashed just as I converted my construction loan to a mortgage and took it in the shorts for $100k hard cash loss on a $300k construction cost. Had I been paying much, much, closer attention to the housing market I very well may have opted to hold on to a bare lot, put up with the developer's rants about not building on it, bought a conventional house closer to the cities, and got just as much or more house for 1/2 the money. And this is a fairly plain box house architecturally speaking.

I will probably never recover my money out of this house. In the mean time I do enjoy the stable temperature inside, the quietness of it, and all the wheel chair and walker friendly features I included, even though neither of us is in a wheel chair or uses a walker.

From a financial standpoint my ICF house built during a hot construction market in 2007 is a disastrous investment. From a living comfort standpoint, I couldn't have done better.

Posted By Dana1 on 18 Feb 2013 06:35 PM
Something that actually does make a difference...

...something like the granite countertops, mayhaps? (It's for the thermal mass, benefit, right? ;-) )

What's the highest wind speed ever recorded in Phoenix?

http://www.azjerry.com/weather/wxwindsummary.php (Not much scary stuff there from a design point of view... )

I get that the snow-loads are pretty low there...

Unless it's a cathedralized ceiling/insulated roof deck there's no thermal performance advantage to an insulated gable end. There IS some advantage to air-sealing the inner EPS to the ceiling gypsum from the attic side with open cell foam though. There is also a significant thermal & comfort advantage to using mass walls in a Phoenix AZ climate if you do the window-SGHC & roof overhang/shading issues right. It takes a lot more thermal mass inside the walls to make up for it if you blow the windows & shading issues though. Spending the extra grand on a better windows (or better load management design) easily trumps a high-mass insulated gable on trussed roof attic where the insulation is at the truss chords rather than the roof deck.

If the roof deck is being insulated to deal with ducts & air handlers in the attic, there's still no particular advantage to high mass gables- it's too little mass, too isolated from the space to matter. High mass roofing would be a different story though.

Yes on both, the gable end is a cathedral ceiling and with a conditioned roof.

As far as highest recorded wind speed, that was in August 1996 and the wind speed was 115MPH from a thunderstorm. It damaged 75,000 homes and cost $160mil in property damage. Many of the homes damage was due to failed gable walls (I am not kidding). During monsoon season (July - September), it is not uncommon to see microbursts or macrobursts with wind speeds reaching 80mph-100mph.

Arizona Weather Facts between 1971-2008:

170 Tornadoes / $45mil in damage
404 Severe thunderstorm weather events - causing $500mil in property damage

FEMA lists Arizona as Zone 1 wind area, they recommend designing homes for 130mph winds. Enter in local code which states differently and homes in Phoenix are designed for 75mph or 90mph wind loads (3 sec burst).

I will never forget that day in October 2010 when 9 tornadoes rolled through Phoenix up to Flagstaff. Most were EF2 and one was an EF3, causing $350mil in property damage. The one tornado came within 10 miles of my place.

Not all poorly designed gable walls end in catastrophic failure. Many, upon many, poorly designed gable walls in newer built Phoenix homes are beginning to show signs of damage. On homes the gable vents are beginning to work loose from the gable wall due to the constant racking of the poorly built gable wall. As the gable vents (which are thin aluminum) begin to twist and rack on the gable wall, they rip apart the flashing around the gable vents. When it rains the rain gets behind the gable flashing and streams down the interior wall causing significant damage to the wood framing and drywall.

Exhibit A (a damaged gable vent being repaired due to racking of gable wall):

Lbear,

Maybe it is time to add a concrete roof to the concrete gables.  GCT has an outstanding choice of SCIP roof panels.

Posted By Alton on 18 Feb 2013 09:53 PM
Lbear,

Maybe it is time to add a concrete roof to the concrete gables.  GCT has an outstanding choice of SCIP roof panels.

Thought about it but the design we are after would not work with a concrete roof. The steel roof SIPs work perfectly for our design and gets me a R-50 value, 24" soffit overhang, and excellent fire and storm resistance. Two guys can put up a steel SIP roof without a crane.

If I were building in the southeast, I would definitely consider a concrete SCIP roof.

What do SCIP roofs go for out east? I remember ICF concrete roofs were going for around $25 per square foot on a 5/12 pitch.

Posted By dmaceld on 18 Feb 2013 06:40 PM

Those are exactly some of the things that have gone through my mind these past four years after the market crashed just as I converted my construction loan to a mortgage and took it in the shorts for $100k hard cash loss on a $300k construction cost. Had I been paying much, much, closer attention to the housing market I very well may have opted to hold on to a bare lot, put up with the developer's rants about not building on it, bought a conventional house closer to the cities, and got just as much or more house for 1/2 the money. And this is a fairly plain box house architecturally speaking.

I will probably never recover my money out of this house. In the mean time I do enjoy the stable temperature inside, the quietness of it, and all the wheel chair and walker friendly features I included, even though neither of us is in a wheel chair or uses a walker.

From a financial standpoint my ICF house built during a hot construction market in 2007 is a disastrous investment. From a living comfort standpoint, I couldn't have done better.

Custom home builds need to be looked at as a labor of love, not for profit. When one can buy a 4-year old home for $50 a square foot, there is no way to financially justify building a new custom home.

Enjoy what you created and built and know that it was done right. Most of the spec/tract homes have problems and are built to minimum code.

When the apocalypse hits, you want to be living in the country and away from highly-populated cities.

I am building my custom full ICF home for around $50 sqft. It was cheaper for us to build a new house then it was to buy an old one and fix it up (deep energy retro mind you). It just depends on what you are capable of doing. Total cost of the project including lot is around $180k. We even have a stable housing market, its just our houses are not inflated in cost and value.

I'd say MOST houses built during the hot-phase of 2007 just before the plug got pulled aren't exactly great from a financial investment point of view, not just ICF houses.

Even in less than boom times it's tough to make the financial argument for high-performance housing. If you're looking at a 7 year net-present value you can't make the energy use numbers work for CODE MIN. What you're buying with ICF or any other uptick over code is comfort, and maybe putting your own price on what the economists call "externalities" rather than merely the cash value the energy offsets over your anticipated tenure in the place.

Very few people had the confidence in their analytic skills to do what physicist Tom Murphy did. Unlike the derivatives-geniuses on Wall Street he did the math, saw the bubble for what it was and SOLD (at a profit) in 2006, in plenty time to not get slammed with an under-water mortgage on a house in a town where he might not be living in a few years:

http://physics.ucsd.edu/do-the-math/2011/11/peak-oil-perspective/

("Do the math" indeed!)

I have a friend and former neighbor still holding onto house under water in Las Vegas from when he was doing a medical residency there in 2006, and that was two houses ago. He is fortunately able to rent the place out for ALMOST what the mortgage payments are, but there's no hope of selling or refinancing any time soon. (He at least broke even on the place down the block from me, sold last spring as they headed off to a longer term job prospect in WA.)

Posted By lzerarc on 19 Feb 2013 09:02 AM
I am building my custom full ICF home for around $50 sqft. It was cheaper for us to build a new house then it was to buy an old one and fix it up (deep energy retro mind you). It just depends on what you are capable of doing. Total cost of the project including lot is around $180k. We even have a stable housing market, its just our houses are not inflated in cost and value.

Is the $50 per sqft the fully finished home cost (drywall, roof, interior finishes, exterior finishes, windows, etc)?

Two thumbs up!

Posted By Lbear on 20 Feb 2013 01:32 AM


Two thumbs up!

what others have said...if its vaulted space, then it does make sense. In mine and many situation where is flat ceiling...it makes 0 financial, and in most cases, structural sense.

Posted By Lbear on 20 Feb 2013 01:30 AM

Posted By lzerarc on 19 Feb 2013 09:02 AM
I am building my custom full ICF home for around $50 sqft. It was cheaper for us to build a new house then it was to buy an old one and fix it up (deep energy retro mind you). It just depends on what you are capable of doing. Total cost of the project including lot is around $180k. We even have a stable housing market, its just our houses are not inflated in cost and value.

Is the $50 per sqft the fully finished home cost (drywall, roof, interior finishes, exterior finishes, windows, etc)?

100% everything. Its 1820 up and 1820 down. It does not include finishing the basement. I assume you have checked my building blog to see what it would include.

Posted By lzerarc on 20 Feb 2013 01:59 PM


100% everything. Its 1820 up and 1820 down. It does not include finishing the basement. I assume you have checked my building blog to see what it would include.

I am shocked if you can build a 3,640 sqft home, completely finished (besides basement), turn-key for $50 a square foot or $180k. Are you 100% DIY?


What is your blog link?

You ask about the cost of the two assemblies: I paid about $10.50/sqft for my ICF turnkey, I figure a $2 up charge per sqft based on needing additional scaffolding that we didn't have on site, plus an additional pumper run at $600, so my 185 sqft of gable would have cost ~$2900 to do ICF.

Costs for wood frame were 2 trusses @ $90 each, $40 of OSB, $108 for 2" of EPS for the outside, $40 for additional interior framing lumber, $20 of additional fasteners (including the hurricane clips), 2" of CCSPF @ $0.75/bdft for $280 on the interior, for a total of ~$660 not including my time, which for the amount of additional work was minimal. I think you can see why I did it wood frame.

For the record I'm in the Colorado mountains in a high wind zone, the assembly was engineered, and my inspector was quite exacting. I have had gusts well in excess of 100 MpH, and the assembly doesn't even wiggle. So I guess what I am saying is that the wood frame may require more care in the details, but the creative idiot can still build an ICF gable where the roof will peel off.

I'm in the same realm as to costs as Izerarc, and I have ICF, geothermal, CCSPF for the roof, and even the fancy counter tops. The only way you get there is extensive DIY and careful allocation of your money.

My ICF home should come in under $50/sq ft. This is 2150 sq ft ICF main floor and full ICF basement; although, part of the basement will be a 1 bay garage. I will also have a two car stick built attached garage at the same level as the main floor. I have ~3800 sq ft heated and cooled. I'm doing much of the work myself, and subbing out the big tasks like framing the garage and interior walls and setting the floor trusses and roof trusses and decking, installing the shingles, brick veneer, etc. I'm estimating $160-$170k finished. It is all about location. I live in a rural area and things generally cost less here.

tis true...others here are in the same spot it sounds like. specs of the home- full ICF, 98% eff. modulating furnace, HRV, 2+1 car garage, underslab foam in basement, custom designed with solar tempering, triple pane Kolbe windows and doors, granite counter tops, TRUSSED GABLES ;) and roof w/ r60 blown insulation with attic seal in flat areas, r55 spray foam in clerestory areas, contemporary designed and themed home...you get the idea. Tasks DIY- layout, form a drain, pour footings, slabs, built and poured ICF walls, installed ledgers, floor system, sheathing, installed all windows and doors, framed and built garage, framed all interior walls, sheathed some of the roof (I did pay a contractor friend to help set the roof trusses and sheath some of it to get it done faster), i built the front porch, set beams and colums, will do siding, soffits, exterior and interior trim work, cabinet and door installs, tiling and wood flooring, and low voltage wiring including full home audio. Items I am paying done: All rough in plumbing, all electrical (I would be doing this by state code requires licenses electrician on NEW construction. my last full reno home I did myself), paid for the HVAC to be installed. Paid for the basement to be dug. Paying for the drywall to be hung and finished. I could do this, but I HATE finishing drywall. Well worth the 5k to pay to have it done. I also paid to have the roof shingled to get it done faster since we are in the middle of winter. Everything else, by me. http://lizerhomestead.blogspot.com/