Frequently Asked Questions
1. Why should I build my home using ICFs?
ICFs create homes and buildings that are more energy efficient, stronger, moresound resistant, and more environmentally sustainable than any otherconstruction method.
2. Exactly how does the home owner benefit from using ICFs?
Comfort. Houses built with ICF walls have a much more even temperaturethroughout the day and night. They have virtually no “cold spots," and farfewer drafts.
Durability. The rigidity of concrete construction reduces the flex in floors andcuts shifting and vibration from the force of the wind or the slamming of a door.Concrete houses survive high-force winds like hurricanes far better than woodhomes. When properly reinforced, they should also withstand earthquakes well.
Quiet. About one-sixth as much sound gets through an ICF wall as compared toan ordinary frame wall. This sharply cuts the intrusion of noise from outside.
Energy efficiency. The superior insulation, air tightness, and mass of ICF wallscuts the amount of energy needed for heating and cooling by 30-40%. This cansave $200-300 per year in a typical home. In addition, it allows the installation ofsmaller heating and cooling equipment, which can reduce the initial cost of ahouse by over a thousand dollars.
Design flexibility. ICF houses can be completed with almost any interior andexterior finishes, and can take any shape as easily as wood-frame homes. Infact, some interesting effects, such as curved walls and frequent corners, can beless expensive to build into an ICF home.
3. Isn't it hard to remodel an ICF home?
Most remodeling contractors have the ability to cut openings into an ICF wall.Most tool rental stores rent out concrete cutting saws for cutting openings.
4. Where have ICF homes been built?
ICF homes have been built all across North America, in every region, andvirtually every state and province. ICF homes are prized in the Northeast, UpperMidwest and Canada for their energy efficiency and comfortable indoor climate.Along the hurricane-plagued Eastern Seaboard and Gulf Coast, ICF homes aresimilarly valued for their durability and resistance to storms. In the Southwest,ICF homes keep their occupants much cooler in the summer and warmer in thewinter. On the West Coast, ICF homes provide safety from earthquakes andfires. In the provinces of Canada, the growth rate of ICF homes has exceededeven that of the United States. Spurred by government programs to encouragethe construction of energy-efficient housing, more Canadian builders alreadyknow what their U.S. counterparts are just now discovering: It is often lessexpensive to build with ICFs from footing to eaves than it is to build a stick-framehouse to the same insulation standard.
5. How energy-efficient are ICFs for my home?
Based on research performed by Building Works Inc., houses built with ICFexterior walls require an estimated 44% less energy to heat and 32% lessenergy to cool than comparable wood-frame houses. A typical 2000 square foothome in the center of the U.S. will save approximately $200 in heating costseach year and $65 in air conditioning each year. The bigger the house, thebigger the savings. In colder areas of the U.S. and Canada, heating savings willbe more and cooling savings less. In hotter areas, heating savings will be lessand cooling savings more. Such energy-efficient performance comes in largepart from the polystyrene foam on the interior and exterior of ICF walls, whichrange from R-17 to R-26, compared to wood frame’s R-9 to R-15 walls. Also, ICFwalls are tighter, reducing infiltration (air leakage) by 50% over wood-framehomes.
6. Are ICF buildings safer than wood-framed buildings?
Yes. ICF buildings are up to 8.5 times stronger than wood-framed buildings. Asa result, ICF walls are more able to withstand severe weather such ashurricanes and tornadoes. Most ICF walls have a 2-hour fire rating, as opposedto 15 minutes for a comparable wood-framed wall.
7. Why are ICFs better than stick framing at dealing with rot and mold issues?
Over the past 20 years, builders have been asked to build tighter wood homesusing house wraps, seals, caulk, tapes, and gaskets in order to reduce theamount of air infiltration/loss in the home. When these products fail, moisturegets trapped inside the open cavity of a wood stud wall, causing mold andmildew problems and rot. ICFs are closed-cavity construction, with the concretefilling the entire cavity of the wall. Given that there is no place for moisture totravel in the wall, and that foam, steel reinforcing bar and concrete are all threeinorganic material, ICFs are resistant to mold and mildew problems.
8. How much do ICF walls cost?
Because of low labor requirements, total construction cost is only slightly abovethe cost of wood-frame, despite the use of high-quality materials. When built bycrews experienced with ICF construction, completed ICF homes cost about 0.5to 4% more than they would if they had been built of frame.
Putting the numbers differently, building a house of ICFs adds approximately$0.25-3.25 per square foot to the total cost. Simply building the walls addsabout $1.00-4.00. But one can then subtract as much as $.75 in savings fromsmaller heating and cooling equipment.
9. How can I build my next house using concrete and ICFs?
The companies that make ICFs provide extensive information. Home buyers canget the names of experienced nearby contractors. Builders can get productspecifications, instructions, and training. Contact the ICFA at 888-864-4232.You can also search for an ICF contractor at www.forms.org, beginning on thehome page. Ask all the questions and see for yourself how concrete walls withICFs provide a superior house for a modest price.