Howdy ya'll. Planing to build a house in Memphis, TN,  edge of zone 3 and almost 4.  I was gun ho about building ICF until I got my quotes back and realized we couldnt afford it. Builders are limited here and not competitive. So I guess Im trying to get some of the same benefits without the associated costs. 

Heres my plan and I would like yall's opinion of it.

   I would like to use 2x4s filled with cellulose and have the foil iso 1 inch foam on the exterior and taped to reduce air infiltration. Im using brick and stone masonry and believe it or not we are in a big earthquake area so there will be a lot of brick ties and reinforcing steel at the corners.  Hoping the R value should be high enough in walls for my zone and the radiant barrier better for the cooling dominant season. ALso worried about moisture behind the brick. 
    My HVAC is geothermal into a pond with 2 marathon water heaters.  5 tons with 3 zones for 4500 square foot heated/cooled space.  House oriented east/west. Only 3 west windows with shutters.  12 Southern windows, most with 2 foot overhangs and possible awnings for the others.  ANdersen 100 windows double paned and low e glass.
     Im leaning to a  radiant barrier under the roof and foam and cellulose in the attic to save cost.  Alot of people do closed cell foam under the rafters here but is is twice as expensive and I dont think the payback is there.   
    I have heard mixed things about tightness of house....some people like for it to breathe while others dont.  Im going to have alot of foster children in this house and I would like to address their allergies now and not later.   I also understand to monitor the humidity and keep it below 40%.  

What do ya'll think of this plan? Should I have an outside air circulator or continue to clean the inside conditioned air with the filters like they are designed? Should I vent the roof and use radiant barriers and insulation?

Thanks
Doc

I would use 2" of EPS instead of 1" foil iso. Make it really tight and then use a HRV or ERV.

What did the ICF bid come in at?

I have heard mixed things about tightness of house....some people like for it to breathe while others dont.

I think you might need to look into this in a little more depth before you move forward.

Jonr already mentioned the ERV.

Have you looked into a cool roof? Not so sure about the radiant barrier. Who said you needed that?

Did you look into doing something less expensive than geo and putting the savings into the envelope?

I would like to price out a cool roof if possible. My roof is huge though so I don't know if it will be cost effective. 120 squares. I assumed being in the south you would want a radiant barrier to reflect heat out of the attic. And the contractors push it down here. Would you recommend more cellulose instead and avoid the radiant barrier.
I've gotten a range of 11-16 per square foot of wall. About 6800 feet of wall.

So no iso foam. Should I be worried about permeability of eps when the brick dews up?

So it's better for allergies to have a tight home an bring in fresh air? Does that reduce the efficiency some?

Thanks y'all.

On the allergies. It's better to have a tight home since you can filter the incoming air to remove allergens, at least if you're allergic to outside stuff like pollen or ragweed. However if you're allergic to indoor stuff like pet dander, then it probably doesn't matter as much either way but in that case you want to run the indoor fan more often to remove that (and avoid carpet).

A tight home can be more efficient since you recover some of the lost heat when exchanging air. Just don't exchange too much (or too little or you'll get sick). With a loose house the air exchanges depend on the wind and open doors\windows which is not very controllable especially in winter where you keep everything buttoned up.

I would like to price out a cool roof if possible.

It's primarily the selection of roofing color so shouldn't cost any more on new construction.
Radiant barriers can help with a variety of construction sins, primarily inadequate insulation. But, that's not going to happen to you.
More insulation is going to be better for you than the radiant barrier.
$11 - $16/ft is good for ICF. If you can go with the lower bid there in Memphis, you should be able to do pretty well with the ICF plan.
What is the configuration of your plan? 6800 sf of wall? 120 squares? 4500 sf conditioned? Having a hard time seeing how that works out.

Thanks on the allergies. The plan has a lot of outdoor space under roof,lots of corners, 2 stories with a garage. Long and skinny rectangular oriented with the long sides north and south. Only 2 contractors in area familiar with ICFs and they are just not go getters with their subs. My price with subs is close to being on budget but not quite. We would have to make significant cuts. However going stick frame with a go getter contractor is saving me 50,000 and allowing us to add a tornado shelter, extra insulation in roof and walls, sprinkler system, and all without having to make a bunch of cuts.

Most contractors are cost plus 10 around here and I am starting to realize that this gives no incentives for the contractor to save you money. Im aiming to pay a flat fee of 10-12% plus a bonus if it comes under budget.

I don't see how the numbers work out either. 6800 square feet of wall at say, 10' wall height is 680 linear feet of wall. If it were square, that's 170 feet/side. or 28,900 sq ft. I know you said it is a long skinny rectangle, but you might want to consider a more efficient shape. You really only need ICF walls for heated areas; garages and outside walls that don't created any heated area could be CMU. I think one should consider the 'bones' of the house above aesthetics, especially if cost is a major factor. We kept our house small and simple in order to have the very best construction for efficiency and durability. To each his/her own. I only did ICF on the heated area, with the attached garage being 2X4 construction.

Agreed that custom home design is the ultimate case of to each his/her own. That said, there is a considerable risk in this housing market in ignoring aesthetics. Appraisers in my area won't give you full value for new stick-built after applying foreclosure shortened comparables. You'd want to see how many real estate agents in your area know what ICF stands for before sacrificing a distinct design that pleases you and perhaps prospective buyers as well. You may plan to live in it forever but that answer only works if you know for certain that "forever" is at least five to 10 years.

Posted By jdebree on 28 Oct 2012 07:47 AM
I think one should consider the 'bones' of the house above aesthetics, especially if cost is a major factor. We kept our house small and simple in order to have the very best construction for efficiency and durability. To each his/her own. I only did ICF on the heated area, with the attached garage being 2X4 construction.

Don't repeat that statement in front of an architect.

Aesthetics vs functionality...

There is no doubt that a box is the easiest to design and the cheapest to build, a simple square or rectangle. Simple illustration: As men when we look for a female companion to date and potentially become our wife, we don't simply choose that person based on "functionality". Her functionality or personality matters but looks/appearance play a LARGE part in our selection process. There are many "functional" women out there but sadly & truthfully they don't get chosen as often because of their looks.

The point of the above is that aesthetics matter. We are not robots, nor are we dull emotionless creatures. We are drawn to beauty both in nature and what we create as human beings with our own hands. When it comes to custom home building it usually requires both factors to be present, aesthetics and functionality. There is always some give and take but to disregard aesthetics is both artistically sad and will also become a problem if/when the home goes up for sale. When people buy homes they look at aesthetics and then functionality. Very few people, maybe 5% disregard aesthetics completely and merely look at functionality.

When one comes home and sees this beautiful artistic expression waiting for them, it's an awesome feeling that is intrinsically human. Did I just talk about the home or the wife? I actually talked about both. There is nothing wrong with coming home to a house and wife that is merely functional but most people prefer to come home to a house and wife that are BOTH functional and aesthetically beautiful.

I guess I over-stated my case. Aesthetics are very important, obviously, but if you're trying to be energy-efficient and cost-conscious, you have to be willing to compromise on your design. I'm always amused when people cut corners on house construction to free up money for granite countertops and a Wolf range. This is Green Building Talk, after all, and the O/P is looking for ways to cut costs. I even offered some ways to cut costs without changing the aesthetics. Sorry if I offended; that was not my intent.

Again, to each his/her own but .... Green building is a set of tools and systems that allows one to accomplish energy efficiency in one's design, whatever that may be. Design itself can be green. If Doc could find happiness in a house of 2,250 sq ft, for example, his house would be twice as green and cost less besides. In my world view, what America needs is a not-so-big house with curb the appeal and livability of a McMansion, in no small part because inflation in construction materials will continue as we compete with the developing third world, even as natural gas fracking takes the heat off energy costs. And, yes, efficient use of construction materials is also green.

But again, to each his/her own... Doc deserves kudos for paying attention.

Posted By jdebree on 29 Oct 2012 08:38 AM
I guess I over-stated my case. Aesthetics are very important, obviously, but if you're trying to be energy-efficient and cost-conscious, you have to be willing to compromise on your design. I'm always amused when people cut corners on house construction to free up money for granite countertops and a Wolf range. This is Green Building Talk, after all, and the O/P is looking for ways to cut costs. I even offered some ways to cut costs without changing the aesthetics. Sorry if I offended; that was not my intent.

We are just discussing, no offense taken here. Tract homes as found in 97% of suburbia always cut corners on construction in order to put more money towards the "lipstick" on a home (granite tops, stainless appliances). When it comes to custom homes, that is a totally different animal because the home builder is designing and building a home based on what they want. If this involves an architect, which most custom homes do, then the home builder and architect meet to discuss what the goals are of the builder. Unless one has an endless bank account, there is always give and take when it comes to design, costs and functionality.

There are many energy efficient designs out there that are aesthetically pleasing. They are beautiful to look at it and they attain great energy numbers. It comes with proper planning by both the architect and builder. Unfortunately there are the boxes. There is a disdain in the architectural world for many of these "green homes" because they are basically boxes. These designs give the energy efficient home a bad name. People think that in order to be energy efficient, you are stuck with a shoebox design. This actually makes many people shy away from custom homes and building green. There is a movement in the architecture community to get people to understand that a home can be both green and aesthetically pleasing.

I know of a particular energy efficient home that was built a few years ago and it was basically a 2,000 sqft rectangle. Most people who drive by it think it's a double wide manufactured home. There has been so much resentment against the home because of the way it looks that the HOA actually had to change its architectural amendments to prevent another such home from being built. This home has single handedly plummeted the property values of the area and it has made many people refuse to buy land in the area to build their custom homes. They go and buy elsewhere. When someone asks why did they allow such a home, the most common response was, "it is a green energy home". That is a lot of bad press and stigma that this home has brought and will bring for years to come. People think green means ugly. So why build green?

Good responses. If I were alone I would live off the grid with a small house 20 feet from the pond, but I am married with 3 kids and hoping to add 2 more fosters so space is a premium. My brother is the architect, and I love his work so aesthetics are very important. As you can see in the plan there are alot of extra walls to accommodate a courtyard to relax in and other areas to let in light to the kitchen. But it is still oriented correctly and rectangular in shape so compromises were made. Im hoping to make it a good mix of energy savings plus meeting all our other needs as well. Attached are some pictures. Well it looks like we are officially abandoning ICFs. Would ya'll recommend 2x4 construction with the 1 inch xps external foam or the 2x6 with more insulation and foam strips on studs to stop heat conduction. My contractor has not done foam on outside before so I don't want to be a guinea pig unless the benefits are significant. Tyvek will be wrapped around whichever we go through. Thanks for all your help.

Pic 1- well i though I would attach pics but doesnt seem to be working. Will work on it after lunch.

My plan, had I not gone ICF, was to go 2X6 walls with blown in cellulose, and exterior foam. I'm also kind of a worry-wart when it comes to bad weather (living in FL for 30 years will do that to you) so I like the stronger walls. I would have fully sheathed the outside walls, then applied sheets of foam. These buildings with solid sheathing only in the corners scare me. To get the best efficiency on stick construction, you need to be sure everything is sealed up well. Air leaks are now being found to be as big a culprit as lack of insulation in some cases. ICF is not necessarily the best route anyhow; there are things about it I don't like, but the pros out-weighed the cons in my case.

If your builder knows his stuff, you can go with Advanced Framing with 2X6's, resulting in more insulation and less heat bridging. It does have to be done right, though.

Posted By jdebree on 29 Oct 2012 05:21 PM
My plan, had I not gone ICF, was to go 2X6 walls with blown in cellulose, and exterior foam. I'm also kind of a worry-wart when it comes to bad weather (living in FL for 30 years will do that to you) so I like the stronger walls. I would have fully sheathed the outside walls, then applied sheets of foam. These buildings with solid sheathing only in the corners scare me. To get the best efficiency on stick construction, you need to be sure everything is sealed up well. Air leaks are now being found to be as big a culprit as lack of insulation in some cases. ICF is not necessarily the best route anyhow; there are things about it I don't like, but the pros out-weighed the cons in my case.

If your builder knows his stuff, you can go with Advanced Framing with 2X6's, resulting in more insulation and less heat bridging. It does have to be done right, though.

They only shear the corners out here in Phoenix also. These houses leak air like crazy and rack a lot during high winds. A Phoenix built home WOULD NOT survive a constant 70MPH wind gust. It would fall apart. The code out here is lax, it is a 70MPH (3 second) burst.

What things didn't you like about the ICF?

Here are some Net Zero Homes that are of course energy efficient and nice pieces of architecture:

Trial # 2 on pics