Making the Business Case for Building with Insulated Concrete Forms: Energy, Safety, and Savings

Insulated concrete form construction can help ensure energy efficiency and noise control while keeping projects on budget
 
Sponsored by Build with Strength, a coalition of the National Ready Mixed Concrete Association
1 AIA LU/Elective; 0.1 IACET CEU*; 1 AIBD P-CE; AAA 1 Structured Learning Hour; This course can be self-reported to the AANB, as per their CE Guidelines; AAPEI 1 Structured Learning Hour; This course can be self-reported to the AIBC, as per their CE Guidelines.; MAA 1 Structured Learning Hour; This course can be self-reported to the NLAA.; This course can be self-reported to the NSAA; NWTAA 1 Structured Learning Hour; OAA 1 Learning Hour; SAA 1 Hour of Core Learning

Learning Objectives:

  1. Identify the economic benefits of building multifamily projects with insulated concrete forms (ICFs), including first cost and long-term value.
  2. Define the basic design criteria and construction elements of structures built with ICFs for multifamily residential projects.
  3. Explain how ICF construction can benefit the health, safety, and welfare of occupants in multifamily buildings.
  4. Evaluate the energy-efficiency, disaster-resilience, and noise-mitigation properties of ICFs.

This course is part of the Concrete Academy

[ Page 3 of 5 ]  previous page Page 1 Page 2 Page 3 Page 4 Page 5 next page

First-Cost Comparison

Senior Living Facility: ICFs versus Wood Frame

ICFs can easily be compared to wood-frame construction to assess long-term cost savings. One example is a senior living facility in Oconomowoc, Wisconsin:

  • Total size of wood-frame construction = 176,444 square feet
  • Cost of wood framing including the exterior insulation = $4.32 million or $24.48 per square foot
    • The codes have stepped up to increase insulation requirements on the exterior of multifamily buildings, which also drives up the costs.
  • Cost of wood framing minus the exterior walls = $3.4 million or $19.27 per square foot
    • This is the same project without exterior walls. Wood is only used on the interior (for example, trusses, floor joists, interior walls).
  • Cost of ICF exterior walls = $950,000 or $5.38 per square foot
  • Total for wood frame = $4.32 million
  • Total for ICFs plus wood frame interior = $4.35 million

Pros of ICFs During Construction

ICFs offer the following benefits for projects like the senior living facility discussed above.

  • Ability to pour stair towers and elevators shafts concurrent with structure, also making both more soundproof. For example, a mason does not have to come in to run a CMU shaft prior to the walls going up.
  • Eliminate exterior vapor barrier.
  • Continuous R-22 or greater continuous insulation with the added bonus of concrete thermal mass.
  • Can pour in winter conditions (down to 15 degrees Fahrenheit because both sides of the wall are insulated; the contractor simply insulates the top of the wall).
  • Structural integrity of the wall allows for numerous possibilities, including hanging balconies, masonry tower, or trash chute tie-offs, skip hoist tie-offs, etc.
  • Improves sound transfer through the exterior wall.

The best long-term savings occur in climates where the average daytime temperature goes above and below the interior temperature. The concrete will act as a thermal mass, eliminating the need for heating or cooling spaces in those conditions. In a cold environment like Wisconsin, there are many benefits to using ICFs.

Cost Comparison: ICFs/Steel Stud versus Wood

ICFs can also be compared to wood/steel stud construction. The example below discusses a 60-unit structure in Sarasota, Florida, with 71,769 total square footage.

  • Total for wood frame = $24 per square foot, $1,722,456
    • ncludes Florida hurricane bracing requirements and treating the studs for termites, both of which increase the price.
  • All concrete/steel stud:
    • ICFs = $920,000
    • Precast concrete with stairs and topping = $680,000
    • Steel stud interior walls = $175,000
  • Total for ICFs/steel stud = $1,775,000

Pros of ICFs in Florida

As the Mexico Beach home in the introduction illustrated, using ICFs in Florida provides the following benefits:

  1. Disaster resistance
  2. Mold resistance
  3. Termite protection
  4. Energy efficiency

Overall, ICFs provide long-term value for occupants and owners. They are cost competitive with wood per square foot. However, the thermal properties and durability of ICFs often outperform wood for greater life-cycle savings.

[ Page 3 of 5 ]  previous page Page 1 Page 2 Page 3 Page 4 Page 5 next page
Subscribe to Architectural Record.
Originally published in May 2021

Notice

Academies