Why ICF Homes Are Energy Efficient
As you’re probably aware, insulated concrete forms—ICFs, for short—are one of the newest home building and renovation trends. This is due, in large part, to all of the energy efficient benefits that comes with the material. The energy efficient benefits of ICFs include:
- Requiring less energy to heat and cool
- Absorbing temperature swings
- Less structural leaks
- Resistance to climate-based fluctuations
- Longevity of the material
In this article, we’ll take at each of these factors that make ICF homes significantly more energy efficient than traditionally-built homes.
ICFs Require Less Energy to Heat and Cool
Houses built with ICF exterior walls require an estimated 32% less energy to cool and 44% less energy to heat than comparable wood-framed houses. For larger homes, the energy-saving benefits still apply; the bigger the house, the bigger the savings on utility bills. For colder areas of the United States and Canada, heating savings will be more and cooling savings less; whereas hotter areas (such as Arizona and Miami), heating savings will be less and cooling savings more. Typical savings were estimated, on average, $200 annually on energy costs. In short, ICFs require less energy, which means more money in your pocketbook.
ICFs Absorbs Temperate Swings
Another factor that makes ICFs such a great building choice is that they do more than just cut down on energy loss. Because they’re made of heat-absorbing concrete (the “thermal mass” of ICF), ICFs are able to retain and smooth out large temperature swings, such as desert climates that are hot during the way and near-freezing at night. In a similar fashion, interior temperatures are more regulated thanks to ICFs, as the walls absorb heat or absorb excess heat for a more stable indoor temperature. By some estimate, this “adding back” of energy contributes to nearly 6% of energy needed for free.
ICFs Have Minimal Structural Leaks
One of the key factors that makes ICFs an energy-efficient choice is their tighter fitting structure, which allows for less air leakage and outside air infiltration vs. wood-frame homes. According to several studies, most prominently a study including 58 single-family houses across the United States and Canada, it was discovered because ICF-built homes had an overall tighter construction and less leakage.
Energy Efficiency in Different Climates
Another important study performed by the Portland Cement Association entitled Energy Use in Residential Housing: A Comparison of Insulating Concrete Form and Wood Frame Walls, also showed the benefits of ICFs vs. wood-framed homes was performed in 5 metropolitan areas with vastly different year-round climates (Chicago, Miami, Phoenix, Seattle, Washington D.C.). The conclusion of the study showed that ICFs outperformed traditional wood-based structures, as well as a control group that had no comparable insulation methods beyond the minimum specifications of the IECC. The reason for this is that standard ICF walls greatly exceeds minimum IECC (International Energy Conservation Code) requirements. It should be noted that wood-based structures did outperform minimum IECC standards, but to a much lessened degree. Also worthy to note is homes with ICF-based walls had energy savings that ranged from 5% - 9% greater than the houses with wood-frame walls.
Another significant effect of ICF-built homes that their energy-efficient design allows for is smaller and more cost-effective furnaces and compressors. Building with ICF ultimately requires less-powerful HVAC output, which can reduce construction costs by an estimated $500 -$2,000 per home. And to further emphasize this point, the larger the energy-savings, the greater the overall savings (towards the $2k mark).
This is also corroborated by the aforementioned Portland Cement Association study, which showed additional savings from a reduction in the HVAC system requirements. Total system capacity for houses with ICF walls ranged between 14% - 21% less when compared to houses with wood-framed walls.
There’s also the question of longevity when it comes to ICF versus wood-framed homes. Considering that ICF homes have concrete exterior walls from the footers to the roof, there is a significant reduction of leakages from rotting walls around doors and windows that can go undetected. Furthermore, ICFs show significant resistance to a variety of tunneling vermin, which can gradually cause leakages and eventually erode the structure of the home. Wood-based structures, on the other hand, can create problems in the future that will erode overall savings benefits.
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