The growth of ICFs in the education sector over the past decade has been astonishing. Independence High School near Dallas is one of hundreds of ICF schools now scattered across the United States.
ICFs are a construction method that combine steel-reinforced concrete with rigid foam insulation to create a structure that is extremely strong and exceptionally energy efficient. Originally invented in the late 1960s, the technology first found success forming insulated residential basements, but ICFs have proven to be equally well-suited for commercial construction.
“ICFs are a good fit for any commercial owner that will pay their own maintenance and utility bills,” says Randy Daniels, West U.S. commercial business development advisor at Fox Blocks, “Additionally, the initial construction costs can be lower than the traditional wall assemblies of schools.”
ICFs have found their greatest commercial success in the education sector, where school boards value speed of construction, economy of build, and reduced energy costs for as long as the building is in service.
Over the last 10 or 15 years, close to 300 ICF schools of all types have been built across the United States, and school districts report they’re saving hundreds of thousands of dollars annually in operating expenses.
ICFs have proven to be a fantastic option for building schools. They offer speed in construction, strength and durability, and remarkable efficiency.
“Energy efficiency is much more on the minds of commercial builders and commercial owners than it is for individuals,” explains Martin Clark, director of business development at Nudura. Clark was instrumental in getting ICFs specc’d on several landmark schools in Kentucky more than a decade ago, and has remained deeply involved as the sector has evolved. “ICFs are versatile, energy efficient, sound deadening, easy to use, and readily available across the country,” he continues. “The biggest challenge is getting people to try it initially.”
Cameron Ware, regional sales manager for Nudura, introduced ICFs to the Texas school market, and deserves much of the credit in growing the market from a single school to over a hundred in a few short years. He explains, “Architects and engineers have historically assigned a relatively low value to [the efficiency] of walls. However, huge advances and improvements in roof design, air infiltration, reflective barriers, etc. have increased the burden on the walls, in effect they have become the weakest link in the chain. This is evidenced by significant differences in the energy performance of ICF schools over schools constructed with other wall technologies such as insulated steel and masonry block (CMU).”
While energy savings are significant—frequently reducing heating and cooling loads by 30% to 50%—school districts today choose ICF for the additional benefits they bring to the table.
“It’s not about the efficiency,” says Daniels, “It’s about speed and cost. The single biggest driver is initial cost.”
Clark explains, “They’ve got to make it within budget. The state allocates what it’s going to cost, and the designers and builders have to work within those parameters.”
Most school districts have a choice on the shell, and alternatives include steel stud, tilt-up, and CMU. Experience has shown that ICFs are typically more economical than any of those options.
Bartlett Cocke General Contractors, one of the largest commercial construction firms in Texas, has built schools across the state with a wide range of materials —including ICF—and analyzed the real-world construction costs.
With CMU or tilt up, the interior face of the wall must be furred out, insulated, then covered with drywall. The outside face gets a weather barrier, continuous rigid insulation, then an air gap and then the finish. Barlette Cocke reports that, in Texas at least, the finish-to-finish cost of the wall ends up two to three dollars more per square foot compared to ICF.
With steel stud, the strength and efficiency of the wall is lacking. Daniels says, “What we’re seeing is steel stud being flipped to ICF because in any life cycle assessment over five years or more, ICFs are the low cost solution.”
Because ICF walls go up so quickly and reduce the number of trades needed to finish the wall, Clark says there is typically a 10% to 15% reduction in the overall construction schedule. “Speed of construction is a major component [in why districts choose ICF],” he says.
Additionally, it’s a better wall. Solid steel-reinforced concrete rather than CMU, with four or five inches of continuous insulation rather than the 2.5 inches used on a furred out wall.
The additional insulation means significant savings—usually in excess of 20%. For example, Warren County School District in Kentucky, which adopted ICFs and other energy saving technologies a decade ago, is now saving more than a million dollars annually in utility costs. The trend is towards “net-zero ready” schools; a structure that with the addition of solar panels or a wind turbine, will generate as much energy on site as they consume.
Ware says, “The Leadership in Energy & Environmental Design (LEED) and the International Energy and Conservation Code (IECC) have all but guaranteed that the growth of the ICF market will continue. …Solar panels may appear sexy but a review of LEED and IECC [criteria] shows that standards are evolving to create stronger emphasis and requirements as they apply to the building envelope. …Today’s typical ICF design delivers performance that significantly exceed performance metrics of both LEED and IECC for many years into the future.”
Daniels summarizes, “ICF is just a faster, stronger, better performing option, and it offers massive structural superiority.”
Clearview Elementary School in Pennsylvania was one of the very first schools built with ICF. Completed in
2003 and built with Eco-Block, it achieved at LEED Gold rating, and still saves
the school district $18,000 annually in energy costs.
About this same time, Holdfast Technologies, an Ohio-based Nudura distributor, was working with school districts in Kentucky to consider ICF for their new schools. Clark recalls, “I went and presented ICF schools to the facility director. Warren County School District had just hired an energy manager, so energy use was a big concern for them. They were interested, and wanted to go see one.”
Unaware of the school in Pennsylvania, Holdfast scoured their network for leads, and soon learned of a private parochial school built with ICF in Bentonville, Arkansas. They agreed to host a tour, so Clark, along with architect Kenny Stansfield of Sherman Carter Barnhart (SCB), and Charles Rector and Robert Rogers from the school district went for a road trip.
“It was around 40,000 sq. ft., and all of the interior and exterior walls were ICF,” says Clark. “They had chosen ICF because they’re located in tornado country, and wanted a school that was safe. Interestingly, the parents and the kids had stacked most of the ICF, with a professional concrete contractor placing the concrete. The facilities director [from Kentucky] asked if they didn’t mind sharing their utility bills. Then it became literally a no-brainer, and on the drive back, they made the decision to build with ICF.”
The result of that trip was Alvaton Elementary, an 80,000 sq. ft. public school near Bowling Green, Kentucky, (see sidebar on p.16). Kenny Stanfield of SCB and Ken Siebert of CMTA Consulting Engineers handled the design work, including new details and the recalculation of mechanicals. Furthermore, the team had to seek approvals from the state to approve the use of ICF for school construction. This process took time, and Alvaton Elementary actually started three months behind schedule. Clark says, “Once the ICF installation started, the team was elated at how quickly the walls were completed and the GC was able to recover lost time and open the school on schedule. Ultimately, the speed of ICF technology construction has proven to be an extremely important benefit that was not anticipated originally.”
Built with Nudura ICFs and completed in 2006, it transformed school construction in the region. Bowling Green was—and still is—one of the fastest-growing areas in the United States, and there were several other schools at the time on the drawing boards. With the success of Alvaton, these were also converted to ICF, each one being progressively more economical and efficient.
This effort culminated with Richardsville Elementary, the nation’s first net-zero school. Built at a cost comparable to any other new school project, it uses only 18 kBTU per year (EUI) compared to the national average at the time of 73 EUI. When completed in 2010, it was ten times larger than any other net-zero project in the U.S.
In addition to the highly efficiency ICF walls, the school took advantage of careful site layout for passive ventilation and cooling, and a rooftop solar array. The construction cost was comparable to traditional school construction (approximately $193 per sq. ft. for Richardsville versus a national average of $190), and saves about $155,000 annually in avoided energy costs.
Understandably, the success of this project generated national publicity, with calls coming in from across the U.S. and even internationally. (See accompanying story on p. 16.)
“We have given over 250 tours of those two schools—Alvaton and Richardsville—to architects, builders, and school boards from all across America and beyond,” says Clark. “ICF schools are now being built in Texas, Virginia, Florida, and other states.”
The next year, Nudura, Holdfast, SCB, and general contractor D.W. Wilburn teamed up again to take the concept to the next level with South Warren High School and Middle School, an immense facility with more than 320,000 sq. ft. under one roof. That makes it the largest school in Kentucky and the largest insulated concrete form (ICF) building in the nation to date. The project does not currently generate electricity onsite, but with an energy use rating of 24.1 EUI, is considered “net-zero ready.”
In total, the Bowling Green area has built at least 12 ICF schools over the past few years. Warren County school district has built seven, and is now saving more than a million dollars annually in electricity costs. The surrounding school districts have built a similar number, and the has been adapted at the university level as well.
In fact, most school districts in the area now mandate ICF construction, and the population continues to grow. “Just this year we’ve built one, finished one, and put another out to bid,” says Clark.
Meanwhile, the concept of ICF schools was gaining momentum in other states as well. About the same time Richardsville opened, Hood River Middle School, east of Portland, Oregon, was creating their own Net Zero classroom addition. It achieved net zero and earned a LEED-Platinum rating from the U.S. Green Building Council. Chris Brown of Opsis Architecture says, “Ultimately the decision to use ICF was driven by the sustainability and energy requirements of the project rather than structural necessity, although the acoustic isolation, and ability to work within the seismic requirements certainly helped as well.” The school has proven to be 55% more efficient than the building code requires.
In Texas, Ware was working with the school districts and architects in that state to investigate ICF. Like Bowling Green, the Dallas-Fort Worth (DFW) area is experiencing rapid growth, with new schools being built regularly.
He found success with Butterfield Elementary in Sanger, on the northern outskirts of DFW. Huckabee Architects had not previously worked with ICFs, but they sent a team to visit the recently completed Alvaton Elementary in Kentucky, and with support from Nudura, the school was a complete success.
Huckabee has since become a major proponent of ICFs in Texas, working with Nudura to build approximately 50 ICF schools in the past 10 years, and several more with other brands as well. Daniels, the Fox Blocks rep, confirms, “Huckabee Architects was instrumental in opening the Texas market. They made their own cost comparisons, schedule comparison, performance comparisons, and could present that data to clients independent of what the ICF folks were telling them.”
Shortly after Butterfield was completed, Burleson Integrated School District, south of Fort Worth, chose ICF for their Academy at Nola Dunn. (See story on p.18.) While other Texas schools had incorporated ICF technology in classroom wings, this would be the first all-ICF school in the state. Built downtown on the site of the old Burleson High School, it was a high-visibility project. The two-story building covers more than 100,000 sq. ft. Ware says “Although ICF was selected primarily to increase energy efficiency, the move from CMU to ICF saved several weeks of construction time and allowed the job to be completed in time for the 2010-2011 school year.”
This was the architects’ first ICF job, but with support from Ware and others, it has proven immensely successful. A geothermal mechanical system keeps energy costs to a minimum, and the extremely efficient ICF walls made it possible to eliminate one entire geothermal well field from the design–approximately 65 wells. This cost saving gave ICF walls the advantage over other approaches such as CMU or steel. The district was able to compare the energy use to a newly completed CMU school of a similar size. The roofing, windows, brick exterior cladding, and HVAC of both buildings were the same. Yet the numbers show that converting the wall system to ICF resulted in a 31.2% improvement in efficiency.
Once the first school was successfully completed, several others followed in close order. Ware says that in 2015, installers bid on five separate ICF schools. At one time, he was supplying product to no fewer than 11 different schools.
Frisco Integrated School District, just outside of Dallas, was already committed to efficiency when they discovered ICF. Cecil Cypert, director of construction services for the district, partnered with architectural firm Corgan, to use infra-red scans to verify the thermal performance of wall systems in the area. They visited two ICF schools, including Academy at Nola Dunn, and concluded that ICF technology significantly outperformed all other wall systems. Steel-stud walls—even insulated to R-values exceeding R-30—did not come close to the performance of ICF walls due to the conduction of the steel red iron and studs in the walls. Likewise, the infra-red tests found that ICF wall performance significantly exceeded walls employing masonry CMU in their design.
Based on this data, Corgan designed Independence High School, the first ICF high school in Texas for Frisco ISD, with Lee Lewis Construction as GC and Skinner Masonry in the role of ICF installer. Since the school’s completion in 2014, Frisco ISD has gone on to construct no less than fifteen additional schools out of ICFs, all but one using Nudura. Corgan has designed at least 10 additional ICF schools.
“It is an option we discuss on our new projects, even if the ultimate decision is not to implement the system. The efficiency of ICF has caused us to look at other areas of the envelope to take full advantage of the efficiency ICFs offer.”
Seeing the success in the DFW region, school districts in other areas of the state also began specifying ICF, and growth has snowballed. Bartlett Cocke, the Texas general contractor, was introduced to ICF on a school project north of Austin, and has gone on to build half a dozen more ICF schools since that project, including the rebuilt high school and middle school in West, Texas.
The original buildings were damaged beyond repair in 2013 when a nearby fertilizer plant exploded. Designed by Huckabee Architects, the 217,000-sq.-ft. building consists of two functionally-independent schools, connected by the cafeteria and gymnasium. All were built out of Fox Blocks ICFs for better blast resistance as well as efficiency (see sidebar on p. 20).
Daniels reports Barlett Cocke has become a firm advocate of ICF schools, “They’re going in saying, ‘This is what we are recommending. It will save on scheduling, it will save on cost.”
Right now, the company has three schools under construction within 15 miles of each other north of Austin, and are self-performing the ICF installation.
The cliché is that “everything is bigger in Texas,” and that certainly applies with ICF school construction. Just in north Texas alone, says Ware, there are 18 or 20 ICF schools in various stages of planning.
“Texas has vastly outstripped every other market in the U.S.,” says Daniels. “There’s probably 160-plus ICF schools in Texas alone. We put a manufacturing plant in Dallas primarily to support the school market.”
Murray Snider, co-founder of the ICF Manufactures Association (ICFMA) and president of Nudura said, “Since 2005 Nudura has specified—and was the basis of design for—over 311 schools and school storm-shelters in the United States. All have been built or are in various stages of completion. In the past four years alone, 93 were built in Texas. Since 2006, 56 schools have been built in Kentucky. Since 2007, 18 schools were built in Ohio, and at least 50 in 10 other states.”
Daniels reports that Fox Blocks has a verified and compiled list of 90-plus school projects including brands Fox has acquired.
Snider says, “I believe that the total number of schools built with ICF over the past decade will exceed 300 if the ICFMA were to report our tally.”
ICFs Go West
In Arizona, the market is being driven by the Catholic Diocese of Phoenix, which has commissioned more than a dozen ICF churches and schools. The Phoenix metro area was gaining nearly 200,000 people every year, and the church was one of many organizations scrambling to meet the needs of the growing population. John Minieri, director of real property and facilities, and his assistant Patrick Hintze took the lead in determining the best way to serve the growing number of parishioners.
In 2011, they decided to give ICFs a chance, using Quad-Lock ICF for a new church in Bullhead City. The change from masonry to ICF cut the cooling load in half, and construction costs were comparable. The diocese was impressed enough that in short order, they commissioned two high schools—Seton Catholic High School in Chandler and Xavier College Preparatory High School in Phoenix—to be built with ICF. They followed up with a Newman Center adjacent to Arizona State University. BuildBlock was selected as the block of choice for all three projects.
Gary Fetters of ICF Specialist, who did the ICF install says, “John and Pat have done so much. We had a meeting with the Arizona school board, and they were willing to come along. They said, ‘The money you’re going to save is huge.”
ICF school construction outside of the diocese is becoming more common, including a Green Safari School built with Amvic; and Ironwood Hall, a community college in the southeastern suburbs of Phoenix that achieved LEED-Silver certification, built with a Fox Blocks product.
From Arizona, ICF use has spread north to the Four Corners area. The Catholic diocese recently completed a school in Flagstaff, and the public school district in Alamosa, Colorado commissioned two others that were completed. This was followed by another in Monte Vista. The Flagstaff school and those in Colorado were built with a Fox Blocks product. The ICF installation on the Colorado schools was performed by IMS Masonry, a Utah-based installation contractor that has traveled as far afield as Fort Leavenworth, Kansas to build ICF schools. Currently, they’re building the first ICF school in Utah about 50 miles north of their headquarters, designed by Design West Architects of Salt Lake City. (See story on p. 26).
“We’ve diversified from brick, block, and stone, and we’ve diversified geographically as well,” says Heath Holdaway, president at IMS Masonry. “We’re licensed in 12 states, and have done work everywhere from Hawaii to Vermont.”
Utah seems to be following the trend of Texas ten years ago. “In 2018, there wasn’t a single ICF school in the Utah market,” says Daniels. “Now there are three under construction.”
This issue highlights ICF schools in Utah, Virginia, Oregon, and Tennessee.
Over the years, a number of complementary products have become common in ICF school construction. For roofs and intermediate floors, steel pan decks are typical. Precast concrete planks, are another popular choice.
Window blockouts are usually engineered lumber, either LVL or LSL for bucks. PreBuck, a LSL product engineered specifically for ICF work, is frequently used. These products can be used for door openings as well. In some cases, the designer specifies Stala, a steel framing assembly that includes the door frame and finish returns as part of the bucking system.
Exterior finishes run the full range from metal panels to brick and all types of stucco, as ICFs work well with virtually any finish.
ICFs are occasionally specified for the corridor walls, but usually these are CMU. Some designs use steel studs with high-impact drywall. “Mostly, it’s a function of where the school district is located and what they’re comfortable with,” says Clark.
Sales managers at the major ICF brands say that much of the growth in the school sector still lies in the future, and they’re happy to assist with construction details, training, and help locating qualified installers. “The biggest competition is tradition,” says Daniels. “When we do get access to a school district, and explain the benefits, they push it onto the A/E community, and we can get it specified.”
To assist in this effort, the National Ready Mix Concrete Association (NRMCA) is hosting a series of education seminars across the U.S. These typically include a tour of an ICF school, and frequently the architect or owners representative will make a presentation
“If the school district is presented this information by the structural engineer, GC or architect, success usually follows,” says Daniels. “Districts are really dependent on the information they get from the designers and construction managers.”
Gregg Lewis, executive vice president for promotion at NRMCA says, “The goal is that the experienced ICF developer will spark the interest of other attendees, who can then be referred to Build With Strength’s design assistance program, which offers up to $10,000 of design assistance to reconfigure their plans to ICF.”
Clark reports that once an area begins building schools with ICF, all sorts of other ICF projects typically follow. “They are driving all of the other sectors,” he says. “If you build a school out of ICF, it has a positive influence on so many other people: the school board members, who are usually prominent in the community; the district employees; the kids who attend the school and their parents; the architects and engineers; the GC and the subs. There is nothing out there that affects the ICF industry more than schools because of how many people it touches.”
Ware adds, “Absolutely, school construction work reaches many, many areas of society. School construction typically occurs only in growth areas, and these areas ultimately need new hotels, new homes, and hospitals as well.”