Research funded by two industry organizations is underway at MIT to answer the following question:
Can residential construction using insulated concrete forms, or ICFs, be more cost-effective and environmentally friendly than current building practices?
Good question. In order to answer the multi-faceted question, it must be broken down into distinct components that can be isolated and tested using rigorous protocol. So that gives us two main categories: cost and environmental friendliness. Unfortunately, those categories require further analysis in order to make a fair comparison between ICF construction methods and current building practices, which for simplicity, we’ll assume means wood-frame construction with batt insulation and an exterior cladding of either stucco (most common here in the Southwest U.S.) or siding.
Let’s analyze this metric first. Does cost refer to the price of the material itself, the cost of the material plus the labor to install it, the total cost of a prototypical building using these methods/materials, or the total cost over time? I’m not sure. According to Lloyd Alter’s analysis at TreeHugger, based upon a research study conducted by the Portland Cement Association (PCA) and the National Association of Home Builders (NAHB) through the NAHB Research Center, Inc., the cost is much higher for ICFs than other methods. Specifically, unit-pricing and assembly-based methods from real-world contractors indicate that ICF construction increases costs by a factor of 38%.
The cost analysis was based on standards used by RSMeans for estimating construction costs. Unfortunately whereas RSMeans’ data comes from thousands of sources across the country for standard materials and methods, resulting in a more statistically valid estimated cost per unit, the study by PCA and NAHB included data from only sixteen contractors. As anyone in the industry knows, the cost of construction varies greatly depending on whether the end product is “merchant” grade or tract or production housing versus high-end custom construction. Since adoption of ICF methods and materials remain low, there isn’t going to be much good data required for production housing cost comparisons.
How is this term defined? According to an article by John Caulfield at Builder, an interim report released by MIT states that ICF construction, “demonstrates the potential energy savings due to the benefits of thermal mass, effective insulation, and reduced air infiltration.” In addition to the completed home’s energy usage, the report will also analyze the life-cycle performance of homes constructed with ICFs versus wood-framed homes. The difficulty here, as Lloyd Alter points out, is that the two primary components of insulated concrete forms – concrete and insulation – are not very environmentally friendly themselves. The styrofoam used for the forms is derived from petroleum, contains numerous toxic chemicals, and if exposed to fire, create extremely toxic smoke. Portland cement-based concrete requires a great deal of energy to manufacture, and the production releases