Insulated concrete forms (ICFs) offer energy efficiency, comfort, safety, and faster construction, in addition to a number of other benefits that contribute to the bottom line for builders and homeowners. They’re becoming increasingly popular as architects around the globe recognize the windfalls of the technology.
In fact, according to a study conducted in 2017, the global market has been growing at between 27.5 percent annually, and the arrow is pointing up for future construction activity. Building with ICFs is gaining momentum over other building methods because with comparable costs, ICFs offer unparalleled comfort, energy efficiency, and safety ratings.
So what are ICFs?
At their most basic level, ICFs consist of two panels of EPS foam with a hollow core in between. The panels are held tightly and firmly in position at regular intervals by plastic webs and can be stacked on top of each other in a fashion similar to Lego blocks.
Diving into more detail, panel sizes and core thicknesses vary from manufacturer to manufacturer. Standard NUDURA panels are 2,5 meters long by 45 centimeters tall, and offered in core thicknesses of 10-, 15-, 20-, 25- and 30-centimeters. The common workhorse form, however, is more along the lines of four feet long with a 6.35 to 6.67cm panel thickness and 15cm core.
Using those standard numbers, typical wall thickness using ICFs is slightly more than 28cm, which makes these buildings arguably the tightest in existence today. We’ve conducted blower door tests on many of our completed ICF buildings and found they allow fewer than .3 air changes per hour. Therefore, we often recommend using energy recovery ventilators to ensure safe air exchange, and that fresh air enters the building without losing heated or cooled air.