Article No: 170
Big D finds big benefits in ICFs
By: Carole McMichael
Considering that Dallas is longtime oil and gas country, it doesn't seem to be a likely place for energy efficient building systems to take root and grow in popularity. But according to Alan Hoffmann, president of Alan Hoffmann Co., a Polysteel distributor and builder, several ICF builders operate in Dallas. A few concrete home builders saw the benefit of the product, but many are people outside of the industry who started out as distributors and became builders. That is the case for Hoffmann.
"When I was in real estate, selling homes," says Hoffmann, "I was, for the most part, appalled with the poor quality of construction. In 1993, at a Christmas party, I found ICFs by happenstance. It hit me that this was the best way there is to build. I struck a deal to be a distributor for Ice Block for all North Texas. I got the product high visibility through my networking contacts. I think I was the first in this area to use ICFs for above-grade housing--at least the first to gain some attention."
First experience surprises
Hoffmann built his first ICF house on spec in Allan, Texas. To create a cost comparison with a stick-built home, he built a wood home with the same floor plan next door. In the process, he met with open hostility from builders. One big developer doing stick-built pulled out of the subdivision because people kept coming by his houses asking, "Why aren't you building like that over there, that's cool. What is it?"
"I took press releases and brochures, screwed to ICF blocks, to radio stations," says Hoffmann. "Channel 8 News came out and covered the 'energy efficient ICFs.' I thought if we built a better product, that is energy efficient and stronger, everybody was going to want it. However, that press coverage didn't bring in any buyers. Instead, it attracted other ICF builders and created more competition for me than anything else." Hoffmann got another surprise when the lender that financed his wood-frame house would not finance the ICF house next door.
Since his first ICF house, Hoffmann has built nearly 60 ICF homes, 20 percent of which he worked on from start to finish.
"Slowly, people are beginning to pay attention to the benefits, especially energy efficiency," he says. "I moved in my own ICF-built house in September of 2005. I have 2,700 square feet, but with 9-foot and 11-foot ceilings, that is a lot of cubic feet to cool. I had the AC on all month, but my first energy bill was only $160. My last energy bill, in my previous home, which was 2,100 square feet with 8-foot ceilings, was $465. It was a stick house that was never comfortable. We were always fighting the cold or the heat. When I moved this summer, which was so oppressively hot, I felt we had moved to an oasis. Once we got the new house to temperature, it stayed there almost effortlessly. I'll never want to live in anything else.
"I also love the permanence of building with ICFs. Our society is so mobile; it makes it hard to convince some people that permanence is an advantage unless they are retirees. My customers are generally people who have owned two or three houses previously. They have experienced the maintenance costs attributed to a house that has not been designed to have a useful life beyond 70 years without major maintenance. In my stick house, there was something new every week. In my ICF house, the thing that will wear out will be the hardware, not the walls. The structure is so solid."
Another major benefit for Hoffman is protection from most natural disasters. He built an ICF house in Lake Whitney, Texas, that was hit by a tornado one week before the owners moved in. It took a direct hit from the storm coming in off the lake; then, the funnel went 800 feet farther and leveled a two-story wood-frame house. According to the owners of the ICF house, they only had to replace four squares of roof material.
Perhaps the most satisfying benefit for Hoffmann is design flexibility. "We are just scratching the surface in design; in what we are doing with this product," he says. "ICFs allow you to be a lot more flexible than wood framing. For example, you can do clear-span rooms. There is only one interior wall on my house that is load-bearing. I could remove the wall of my office and have a gigantic room."
The ICF building process
Hoffmann likes the Polysteel waffle-grid system for residential building because its 9 1/4-inch finished wall (with stucco 10-plus inches) produces a smaller outside wall measurement than most flat-wall systems. That feature reduces the cost of property tax. He says the interlock system of the blocks, which use a tongue-in-groove connection, is useful because it makes the blocks reversible--he doesn't have to alternate them for the stud pattern to work out. Hoffman also says the system's steel ties to polymer because they are stronger in the long run. Finally, he prefers the product's recessed steel strips that prevent potential heat transfer.
To begin with, Hoffman had the foundation engineered according to the soil composition. The foundation, using a post-tension cable system, started with perimeter grade beams and a steel grid, crisscrossing on 8-foot centers. This home's beams were generally 32 inches. On the south side, however, he needed a 4-foot-deep beam that ran the length of the house as a root barrier.
After the slab was poured, a 3-foot piece of rebar was anchored in the perimeter beam. The ICF blocks were slipped over the top of the rebar on 2-foot centers around the whole house.
The walls became an extension of the footing, and a strengthener for the entire slab. After bracing and checking for plumb, the walls were poured. "Using a three-man crew, it took about a week and a half to get to the first pour," says Hoffmann. "We use a 3,000 psi pea-gravel mix. Unless it is really hot, I don't use any additives. We have an hour-and-a-half window per load. The first load took the longest because we were filling in the bottom of the windows. The only time you have trouble with blowouts is if there is too much water in the mix or because of operator error. We don't have problems because we know what we are doing, which means making sure walls were braced and vibrated properly.
"After the second floor was poured, we anchor bolted a treated top plate to the top of the wall and finished the framing. Next, we did standard wood framing on the roof, connecting the rafters to the top plate and hurricane straps. The roof decking has a radiant barrier bonded to the plywood and 30-pound felt laid on top. Combining the radiant plywood, cellulose insulation, continuous soffit vent and turban vents, I get a convection effect, constantly moving the air in the attic. As a result, my attic temperatures are 20 to 30 degrees lower.
"For HVAC, we had an energy audit, but their scale didn't go to R-50, so I think the sizing could go down further. I have a 2-ton unit upstairs and a 2-ton unit down. It is a split system with a two-speed condenser. It has an air exchanger and a humidistat to monitor the humidity, which is key in tight ICF houses. The lot itself is oriented perfectly for solar placement."
The business of new technology
"I'm really interested in product innovation," says Hoffmann. "If I can figure out a way to do things better, then that is what I want to do. It has really changed the way I've been building in the past 10 years, even with the ICFs, but this is a business for profit. Compared with stick-built, using ICFs adds about 6 percent in overall production [costs], but the utility savings more than pays for it. And that doesn't count the savings an owner gets on insurance or long-term maintenance.
"My web site is www.concretehomestore.com. I get a lot of hits off it--my last four projects came from there. I also get business from word-of-mouth and signage. At one open house, someone stopped in while I was still getting ready. He looked around for a half-hour and bought the house. I never got to show it."
Although Hoffmann agrees with many other ICF builders that, right now, the residential ICF industry is customer-driven, he sees it as becoming insurance-driven in the future.
"Insurance companies are getting fed up with paying enormous claims on buildings that are substandard or built below a standard that has already been achieved with ICFs," he says. "I think insurance is going to climb on stick-built. In a hurricane, stick homes are taken down to the slab, but if you have an ICF-built house, you still have an outer structure there, and that is about 50 percent of that building. ICF houses are not falling apart either, so insurers are paying half as many claims on them as on stick houses. That's a significant percentage.
"We need to be looking for insurance discounts on ICF houses. I'm already seeing a discount because I pay the same premium now that I paid on my previous home, which was 700 square feet smaller. I get insurers to classify ICF homes the same as a masonry building, which is a higher classification and higher quality structure. What will drive the business is that, and people seeing that these houses are not blown away."
Because of all the benefits from building with ICFs, Hoffmann doesn't usually present them as concrete structures. Rather, he advertises that he builds a green, energy efficient, sustainable house that is safe, quiet and healthy to live in. "I have horrible allergies," he says, "but not in this house."
Hoffman sums up the small comforts and large cost benefits of ICF homes in a simple phrase that speaks loudly to consumers: "It is just a better house."