FAQs for Custom Homes

ICF is an acronym for Insulating Concrete Form(s). Although various configurations exist, a common ICF block is a 48” long, 16” high concrete form with two 2 5/8” thick Expanded Polystyrene (EPS) foam walls as the forms. These walls are separated to create a hollow cavity, which is filled with reinforced concrete. The cavity may be 4” to 12” thick, depending on the project requirements. Polypropylene ties on 8” centers hold the forma at the proper distance apart, and provide a surface to attach finishes, such as drywall and siding. The blocks interlock and are stacked in a manner similar to masonry; then reinforcing steel is placed inside the forms, and concrete is poured; leaving and extremely strong, airtight, very well insulated wall. Some configurations allow for up to 16” total insulation (r-68), 24” thick concrete, extra tall or long forms, etc.

We are a licensed builder, and provide “turn key” homes in the West Michigan area. Outside that area, we work as a sub through your builder or directly with you the homeowner to “shell” in the home. We are a subcontractor, and you can hire us to perform any level of work, from concrete only to the complete custom home.

R-Value Homes specializes in the planning and construction of highly energy efficient, comfortable, and healthy homes using a combination of Insulating Concrete Forms (ICF), air sealing, passive solar design, triple pane windows, engineered HVAC systems, and energy modeling. Our in-house crews perform all concrete work; including footings, ICF walls, poured walls, and flatwork; as well as rough framing, window and door installation, and air sealing. We use a network of expert subcontractors to provide premium mechanicals and finishes.

We highly recommend a blueprint drawn specifically for an ICF home. The thicker walls need to be accounted for.

Appointments to see homes under construction can be made by using our contact us form. We often have a couple in various stages of construction across Michigan.

• Your home doesn’t need to breath, the occupants do! To that end we provide the correct amount of filtered and conditioned fresh air in each home we build.
• The idea that a house needs to breath is fairly common, but not true. The idea is explained in more detail here.

Since a completed ICF home doesn’t look any different than a wood-framed house, it is quite likely you have seen them and not known it—you can only feel the difference! ICF construction is expanding in both residential and commercial markets; although in some communities quality is a lower concern than the up-front cost. In other portions of the country, ICF use is widespread. Lubbock, Texas now uses only ICFs for their low-income housing; realizing that while the home may cost more to build, it is much less costly to live in. Several developers across the nation are construction communities entirely out of ICFs.

It is not hard, but it is different. Instead of using a reciprocating saw, you use a concrete saw (there are many companies that specialize in cutting openings in concrete) to create your new window opening, line it with lumber, and install the window.

We have worked with multiple ICF block manufacturers; and since we are not committed to any one brand, we can objectively help you find the one best suited to your needs. Different forms have advantages in different applications. Here is a list of block manufacturers we currently work with: Amvic, BuildBlock, Durisol, Fox Blocks, Logix, and Nudura. There are many more available, some we are willing to work with, and some that are not worth the effort.

Costs vary widely depending on the specifics of the project, but it is safe to say Insulating Concrete Form homes cost more than code-built homes. Our experience has been that when compared to a home built to minimum code, a properly specified and detailed ICF home costs 10% more. When compared to a properly detailed and specified stick home, cost increases are incremental.

We are based out of Clarksville, MI. This means it is fairly close for us to build in Grand Rapids, Lansing, Hastings, Ionia, etc. We do provide many of our services in much of lower Michigan, and Northern Indiana as well. While we do not work as a builder in locations over 60 minutes from our shop, we can work with your builder, recommend one familiar with ICF homes, or work directly for you to provide our subcontractor services.

While we do not currently offer design services or stock blueprints, there are many excellent architects and designer we can recommend that you talk with. Additionally, there are multiple online sources for ICF blueprints. Here are a few:

• http://www.designbasics.com/altcon/insulated_concrete_forms_fox_blocks.asp
• http://www.architecturaldesigns.com/icf-house-plans.asp
  
• http://buildblock.com/products/home-plans/
  
• http://logixicf.com/index.php?n=builder&o=houseplans
• http://www.safehomesbycivic.com/

• The short answer is that they start at r- 23, and can be increased to r-68 using insulation inserts. The long answer is that measuring the r-value of the insulation alone only tells a small part of the picture. There are multiple reasons that our basic r-23 wall will significantly outperform a standard r-21 2×6 wall:

1. Airtight. A lot of insulation does little good if the home is not airtight. Modern Energy Star homes leak at a rate of 3 air changes per hour at 50 pascals pressure. Most homes are not even this good. Our homes leak less than 1 air change per hour at 50 pascals. Not reheating all that incoming air is just common sense. Additionally, airtightness is more important than a high r-value when health, comfort, and durability are considered.

• Continuous insulation. Unlike stud walls, in which 25% of the surface area can’t be insulated (due to studs, headers, and plates); our homes have no thermal shortcuts. Thermal shortcuts can reduce the effective performance of an r-100 wall to less than r-18. No, that is not a misprint. Here is the proof. Yes, you can add a continuous layer of rigid insulation to the exterior of your house, which will help immensely, but make sure you add enough. 1” is not enough to mitigate condensation within the wall cavity, but it is enough to severely impact the drying potential of the wall. This may in fact create a greater problem with mold and rot. 

• Rigid (that is, not air-permeable) insulation. Even if air cannot move in and out of a stud wall (it can and does); if air can move within the insulation, it will form what is known as convective loops. These are circular flows of air from the warm side to the cold side; and they short-circuit the insulation by moving heat through convection. This process speeds up as the temperatures outside drop. In other words, the colder it is, the worse it gets! The more dense the insulation, the less the convective looping. Rigid insulation = no convective loops.

• Thermal mass. Thermal mass is the least understood element of this list. It has been dubbed: “The ICF effect”, and it cannot be measured by a HERS rating, an infrared scope, r-value, or any tool but your pocketbook. The concrete sandwiched inside the foam acts as a large heatsink to store and release energy as needed. It does an excellent job at evening out the highs and lows of the day, so that your HVAC system can run low and steady. Thermal mass just laughs at wind chills.

A home we built in cooperation with the Grand Valley School of Engineering has been outfitted with temperature sensors embedded in the concrete core for the full height of the home (basement + 2 stories above grade). Preliminary results show that the core temperature of the concrete significantly lags any change in outdoor temperature. We are talking about days, not minutes or hours! We also noted that the difference in the concrete core temperature (averaged out over the basement and 2 above grade stories) from winter to summer was only 23 degrees. The numbers don’t lie! And there is another layer of foam to further isolate that 23 degree difference from reaching the living environment. Thermal mass is a battery of energy that is rarely accounted for.

The timeline to build an ICF home is similar to traditional framing methods. Commercial projects can often be constructed more quickly, due to the combined steps of framing and insulating. Large sections of wall with few offsets and openings also contribute to the speed of ICF construction.

Drywall is glued and screwed to the polypropylene studs that are integral to the ICF form. Siding is also fastened to the studs. Brick, stone, stucco, and TAFS (EIFS) are done using traditional methods. The latter two methods may in fact be less cost, and the ICF leaves an ideal surface that requires minimal preparation.

Yes, we have done this on multiple occasions. If you do that, you may find yourself spending the majority of your time in the comfortable home addition….