Our homes are one of our biggest investments in life, so how they are built should be carefully considered. Conventional stick-framing has been the standard building method for decades. But as more consumers are demanding durable and energy efficient homes, alternatives such as Insulated Concrete Forms (ICFs) have been gaining popularity.
Why ICFs? 
The most notable feature of ICF buildings is that they are 8.5 times stronger than wood framed buildings. ICF walls are better able to withstand severe weather such as hurricanes and tornadoes, making them superior for high risk weather regions. Also, an ICF wall has a sound transmission classification of approximately STC 50, which is twice as high as a typical wood-framed wall. Loud noises outside an ICF building will be reduced to a whisper inside the building.
Considering that roughly two-thirds of a home's annual energy use goes towards heating and cooling, energy efficiency has become a top priority for homeowners. Based on research performed by Building Works, Inc, houses built with ICF exterior walls require an estimated 44% less energy to heat and 32% less energy to cool than comparable wood-frame houses. A typical 2000 square foot home in the center of the U.S. will save approximately $200 in heating costs each year and $65 in air conditioning each year. The energy efficient performance comes in large part from the polystyrene foam on the interior and exterior of ICF walls, which range from R-17 to R-26, compared to wood frame’s R-9 to R-15 walls. Also, ICF walls are tighter, reducing infiltration (air leakage) by 50% over wood-frame homes.
Are ICFs really green?
While ICFs have do have a significant amount of embodied energy content, it is likely the exterior walls of an ICF house will last over 200 years. The total embodied energy of an ICF system would be repaid in energy savings. Over the 200 year span the, total energy savings would be over 6 times the total energy required by the wall system.
The EPS foam used in ICFs do not produce any CFC’s or HCFCs, and do not contain formaldehyde nor any other gasses which might affect indoor air quality. Both the EPS foam and the concrete are highly durable and have a long service life with no repair or replacement costs. Also, ICF construction generates very little waste, much of which can be recycled on the jobsite.
If you’re considering a LEED certification, ICFs can directly contribute to LEED points. The most important and direct contribution by ICFs is toward the energy optimization credit, which offers up to 10 points. This is the only credit with so many points possible, and represents a significant portion of the overall 69 point possible. The Energy Optimization Credit is based on the percentage of energy savings above the ASHRAE benchmark. The energy savings benefits of ICFs can play a significant role in the gaining of these points. ICFs and concrete can also contribute toward credits for recycled materials, sustainable sites, regional materials, and durable structures.
Advice for choosing an ICF System
It is obvious that each individual ICF building system has different properties that deliver different benefits to the end user. Some have thicker insulation than others. Some are connected with metal ties, others with plastic ties. Some systems are stacked like building blocks, others require assembly. We recommend using GreenBuildingTalk's Professional Directory to find a builder. Once you have found a few, choose a builder that:
1. Has experience with ICFs
2. Offers references in your area
3. Uses a well known ICF brand
4. Has a good ICF crew that worked together in the past
It will be up to you to check those references and to get several estimates. Whichever ICF system you choose, it is important to note that once the ICF project has been correctly installed and the concrete cures, you will be extremely happy with your ICF home.