Cement House

Using and Marketing ICFs

Builder's Perspective

Builders look at building with ICFs for a variety of reasons in addition to meeting customer demand for a strong, durable, quiet and energy efficient home. Builders may simply want to set themselves apart from the competition. They may wish to eliminate the need for an experienced mason, reduce reliance on lumber and its associated price volatility, or, in some cases, build foundations less expensively.

An Austin, TX builder states that factors that influenced him to use ICF construction were market/product differentiation, energy efficiency, product durability, and a lack of quality lumber.

A Florida builder started using ICFs four years ago after seeing the effects of hurricane Andrew, combined with a 100% rise in the cost of lumber, He researched several alternatives to wood framing including ICFs, lightweight concrete block, steel, pre-cast concrete, and hay bale, but decided on ICFs due to their strength, price stability, energy efficiency, and availability. One strength-related concern in his area is resistance to flying debris that will penetrate the walls of a wood framed house, but not reinforced concrete. He decided against steel framing because there was a nine-week delivery period. He chose ICFs over pre-cast concrete because of the energy efficiency benefit. He also looked at spray foam for use in wood framed walls but found that option to be relatively expensive without the added strength benefit.

One Iowa builder uses ICF construction to minimize production delays and provide "flexibility for scheduling." He reported masons are among the hardest to get on site. ICF construction eliminates scheduling problems since masons are not needed to build the basement walls. He has found that ICF construction also eliminates concerns with ground water seeping into the basement, a prevalent problem he experienced with block walls.

A builder in Cincinnati says that he could pour practically all winter given the ability of ICFs to extend the lower temperature limit. But, personally he doesn't pour when the temperature goes below 10 degrees Fahrenheit because freezing people aren't productive and, additionally, he’s found that his concrete supplier won't bring concrete to the site in extreme temperatures. Above

20 degrees Fahrenheit, he "doesn’t even give pouring a second thought."

One builder from Chestertown, MD, who has built 47 ICF homes prefers ICFs over wood frame construction for several reasons. He feel that ICFs provide smoother scheduling on his jobs because they do not require as many trades or steps to complete exterior walls. Steps eliminated include installing cavity insulation, exterior sheathing, and house wrap. His continued use of ICF construction is prompted by his concern for energy efficiency and ultimate affordability. He builds in an economically-depressed area and reasons that if customers have trouble with a house payment they will also have trouble paying utility bills. He intends to use ICFs for his next home because of increased energy efficiency and the overall quietness of the home.

A builder from Austin, TX said that, after having built two houses with ICFs, he prefers the finished product of ICF construction to the finished product of wood-frame construction because he feels it is the best house money can buy. Based upon his experience, "done slowly and properly, there isn’t a better product. . .it is not cheap, not easy, and the subs [subcontractors] do not like it. . .when completed, it’s like a fortress around you."

A Florida builder says that almost all ICF structures will qualify as an EPA Energy STAR rated house. He downsizes the air conditioner from his typical four tons (48,000 BTU/Hr) for a 2,000 square foot house to 2.5 tons when using ICFs. This cuts his costs for the HVAC system. He also installs mechanical ventilation to increase the ventilation rate and avoid "sick building syndrome." He has observed a 33 percent energy reduction in similar model homes by using R-

20 ICFs instead of wood framed houses without insulating sheathing and with R-11 batts.

A Virginia Beach, VA builder estimates that ICF construction adds two to four weeks to the construction schedule, because of shipping issues and due to required setting and bracing before the concrete pour. However, he finds the trade-off well worth it for this kind of construction.

The Chestertown, MD builder involved in the Demonstration Homes Project subcontracts the same framing crew for both ICF and wood-frame construction. After experiencing high costs and delays in building their first ICF home due to problems obtaining a local concrete pumping truck, the framers asked if they could buy a portable concrete pumper to do their own pouring. The lower costs due to the use of this portable pumper paid for the pumper after the first job. This has lowered the framing costs on subsequent homes along with providing better service.

A builder in Iowa has his own crew install the ICF block and rents the concrete pump truck. Using his own crew decreases the material requirements as there is typically greater control of materials ordered and less waste at the end of the job. In one case, there were approximately 20 to 25 blocks of waste out of 918 blocks ordered (2.7 %).