For more than 30 years, a quiet revolution has been taking place in the building materials industry. Ask anyone—the way we design and build homes today is drastically different than in the late 1980s. Not just energy-efficiency requirements, engineering design or the building materials themselves; the needs of structures, expectations of code officials, and desires of customers has fundamentally shifted. Luckily, at the same time, building material science has more than kept pace and in many cases exceeded the needs and requirements for today and into the foreseeable future.
ICFs were initially chosen as a building material to build basements and other below grade structures more cost effectively with higher energy-efficiency than traditional construction methods. The choice of foam insulation for the ICFs was one the greatest developments for ICF technology. Foam insulation in its many forms is the only type of material that delivers insulation for all types of heat transfer: conduction, convection, and radiation. By choosing this material, ICFs create the most highly efficient building envelope possible. Even today, other wall systems are turning to foam to create continuous insulation on the outside of structures to meet code requirements.
One of the greatest challenges with any building material is determining how it will perform under real world conditions. Every product seeks out the best-case scenario for its performance, but the real measure is the everyday results. Since their inception, ICFs have delivered superior energy performance, higher quality, and more comfortable structures.
For those that build, live and work each day in ICF structures, many small differences like quietness, air quality, comfort and stability feel commonplace and are taken for granted. They are qualitative and hard to explain but once experienced they become must-have expectations. It was these feelings of comfort and safety, along with lower utility bills and healthier occupants, which have led to a greater adoption of ICFs and a desire to truly understand how this wall system technology creates these benefits.
The building I work in, on a cold low teens temperature week in December, had the geothermal climate systems replaced about three years ago. For a week, a 22,000 square foot building had no “head” in December. The building temperature dipped slightly to 65-degrees and with everyone working, heated back into the upper 60s.
The past few years have brought many changes to the ICF industry in North America including new and innovative products and applications; making ICFs easier to use and expanding their use in a variety of areas such as ICF door and window bucks, ICF swimming pools, and larger and taller structures. The types of structures being built with ICFs continues to expand across all climate zones and building types.
The continued growth and development of ICFs has led to widespread acceptance. Insulating Concrete Forms has paved the way for the construction industry to meet existing needs and requirements for a broad range of built environments, while satisfying needs and delivering benefits for many classes of consumers.
Test the Future
Five years ago, the major ICF manufacturers banded together to collaborate on projects and research that would help make the increasing adoption of ICFs easier and provide independent research to take the confusion out of the real-world performance of ICFs in the built environment. The first collaboration was the CLEB study that evaluated a standard ICF walls performance against a high-efficiency cavity wall in extreme cold.
Without specific guidance the testing laboratory compared the similar wall systems evaluating their performance in maintaining temperature in an extremely cold environment. The cavity wall was built to Quebec standards: a 2x6 cavity wall with batt insulation and an additional 1/2-inch air gap on the inside to create a thermal break. The ICF wall was a standard 6-inch ICF wall.
The results of that study clearly indicated that beyond the materials, something specific was happening with the concrete core in the middle of the wall that drastically slowed down the effects of the cold, causing a significant lag between the temperature change and the energy needed to maintain the warm temperature on one side of the wall. It’s been anecdotally known that the concrete core slows down effects of temperature change, but it had not been tested until now.
The testing demonstrated that the concrete core was very slow to change temperature and created a “thermal resistance” that significantly increased the thermal performance of the system to such an extent that neither solar heating nor night-time cooling had any short-term effect on the energy-efficiency of the walls of the structure. What does this mean in practicality? That without heating or cooling an ICF structure will continue to perform for an extended period of time before the external temperature significantly affects the interior temperature.
The industry came back together in 2019 and expanded the testing across a variety of built environments and wall types to see if the results were repeatable and comparable: they are. Compared to the most common wall types and materials, once again, the insulated concrete thermal mass demonstrated a thermal resistance to changes in temperature and significantly extended the time before it was necessary to add heat or cooling to an ICF structure to maintain a stable temperature. Releasing these results in 2020, the industry will continue testing and quantifying performance of ICFs as we move into an era of increased climate volatility and increasingly demanding efficiency and resilience focused building codes.
Built for the Future
One of the greatest examples of change in the ICF industry are the types of projects and structures being built with ICFs. In the past 10 years alone, more than 260 million square feet of ICF walls have been built in North America. From the pioneering efforts in Kentucky, building highly efficient and safe schools to large churches, warehouses, multi-story residential projects and single-family homes of all sizes; ICFs have proven that they meet and exceed the needs and expectations of building professionals and end-users alike. These are structures that will continue performing for decades with little maintenance and significant savings.
The driving market factors will continue to lead the building materials industry to create solutions for real world building challenges, code requirements, engineering needs and consumer demand. As we enter an age of changes to our energy production and distribution infrastructure, demands on structures to create, manage, use and distribute their energy will become increasingly more important.
ICFs began as a way to build basements more cost effectively with higher energy performance. Today, that trend continues above grade, to the roof and beyond. Product development, engineering, new materials and applications will continue to drive adoption across increasingly diverse built environments and types of structures.
The future of ICFs is synergy. ICFs create a stable building envelope and an environment to efficiently embrace other building materials and technology, extending quality of life and energy-performance long into the future. It might sound a little fantastic, but the ICF building I work in every day was built more than 20 years ago and still exceeds the energy-efficiency requirements in the latest building codes today. If we can do that by accident, think of what we can do intentionally.