The quality of concrete costs little more.
The many benefits of a concrete building made with insulating concrete forms (ICFs) are available for only slightly more than the cost of ordinary wood frame. ICFs are simple to assemble and they consolidate several construction steps into one. The walls can be economical despite the use of high-quality materials.
How much does an ICF building cost?
Buildings by experienced contractors cost about .5-4% more than wood frame structures of the same design. Typical new U.S. buildings cost $60-100 per square foot. Building walls of ICFs adds $1.00-$4.00 to this figure. But since ICF buildings are more energy-efficient, the heating and cooling equipment can be smaller than in a frame structure. This can cut the cost of the final building by an estimated $.75 per square foot. So the net extra cost is about $.25-$3.25.
What is an "experienced contractor"?
As with any innovative new construction product, the more a crew works with ICFs the more efficient they become. ICF wall-building crews report that their costs drop sharply once they have built 4 or 5 houses. After that they continue to realize savings, but at a slower rate.
Contractors also need experience to size the heating and cooling equipment correctly. Heating and cooling contractors not experienced with structures as energy-efficient as ICF buildings tend to install equipment sized for a conventional building. The equipment is larger than necessary, and thus the buyer loses potential savings. More experienced contractors size the equipment more accurately.
Why is there such a high range in the costs?
The cost of using any construction product is pushed up or down by dozens of factors that change from building to building. But for experienced crews, the major influences on ICF cost are fairly predictable.
To begin you can assume that your building will cost $2.00 more per square foot to build with ICFs. This is near the middle of the historical range. Then adjust this cost premium according to the particular features of your construction project:
Why should I pay more?
Each year, the number of Americans who choose to have their houses built from concrete and ICFs nearly doubles. They cite several big advantages:
Comfort. ICF buildings are far less drafty than frame, have far fewer “cold spots”,
and maintain a noticeably more even temperature.
Quiet. Only about one-sixth as much noise travels through an ICF wall. Occupants are pleasantly surprised by the reduction in noise that enters from outside.
Strength. Owners of ICF buildings feel less flex in their walls and floors. They notice virtually no vibration when they slam a door. Engineering calculations show the walls are much stronger than frame walls in many ways. Field data show they survive many types of natural disaster better.
Energy efficiency. ICF walls cut an estimated 30-40% off the energy used to heat and cool a structure. This means lower energy costs, to the tune of $200 to $300 per year for a typical building.
What’s the bottom line?
When planning a building, you can estimate that experienced crews will add $.25-$3.25 per square foot for the cost of building the walls from concrete with ICFs. More precise estimates come from adjusting a mid-range figure (about $2 per square foot) to reflect the specifics of your particular project, or from exact quotes from the contractors and suppliers involved.
Weigh this incremental one-time cost against the range of benefits that ICF walls will add to your building over its lifetime. You will see that because of their high quality, insulating concrete forms are the economical choice.