Foam Insulation FAQs

Insulation works by blocking one or more methods of heat transfer. There are 3 different ways that heat (energy) is transferred (gained or lost):

  • Conduction is the transfer of energy from one molecule to another by direct contact. This is as simple as when you place a pot on a stove to boil. The heat is conducted from the flame or heated surface into the pot and the water. 
  • Convection is the movement of heat by a fluid such as water or air. Think of a hot air balloon. The air is heated from the burner and rises in the balloon creating lift. The cooler air falls to be reheated again. The same effect is seen in the formation of thunderstorms. Hot air rises until it’s cooled, condenses with water vapor and falls back to repeat the cycle.
  • Radiation is the transfer of heat by electromagnetic waves. One of the most familiar forms of radiation is heating via a microwave oven. Microwaves emit a frequency that causes water molecules to vibrate faster and have more energy which we feel as heat. Additionally you can feel thermal radiation after a hot day, the ground and especially concrete sidewalks or streets will radiate heat back into the environment as they cool and try to reach equilibrium.

EPS and other foam insulations are the only type of material we have today that can stop or slow all three types of heat transfer: Conduction, Convection and Radiation.

ICFs are made from a combination of Expanded Polystyrene Foam (EPS) and Polypropylene plastic. The EPS foam is one of the most efficient and longest lasting insulation materials available today and the strong polypropylene plastic webs are molded to provide placement for rebar, embedded studs for attachments and provide strength to withstand the pressures of the concrete during the pour to keep the panels together during the pour.

Expanded Polystyrene (EPS) is a thermoplastic, closed-cell, lightweight, rigid-foam plastic. The low thermal conductivity, high compressive, strength and excellent shock absorption properties of EPS makes it an ideal material for the application demand for which it is used.

Polystyrene foams are produced using blowing agents that form bubbles and expand the foam. In expanded polystyrene, these are usually hydrocarbons such as pentane, which may pose a flammability hazard in manufacturing or storage of newly manufactured material, but have a relatively mild environmental impact.

We interact and benefit every day from products manufactured from polystyrene plastic, including thermal insulation for food containers, medical packaging, construction applications and cushion packaging for industrial and consumer goods.

There are two common types of polystyrene foam: extruded polystyrene (popularly known by its Dow trademark, Styrofoam®) and expanded polystyrene (EPS). The common coffee cup is a perfect example of expanded polystyrene. This is the same material you find when you unpack a new television, stereo, computer, or other delicate consumer product.

Both expanded polystyrene (EPS) and extruded polystyrene are used extensively as thermal insulation in industrial, commercial and residential construction.

Extruded polystyrene is usually made with hydrofluorocarbons (HFC-134a) which have global warming potentials of approximately 1000–1300 times that of carbon dioxide.

No. EPS foam products have never been manufactured with CFCs. The expansion agent for EPS material is pentane which may pose a flammability hazard in manufacturing or storage of newly manufactured material but has a relatively mild environmental impact.

No. Extruded polystyrene (often in colors such as pink, blue or green) uses a different blowing agent and a different manufacturing process. EPS insulation systems dramatically reduce energy consumption and its resultant pollution.

No. EPS foam’s chemical makeup consists of carbon and hydrogen. When completely combusted, it gives off water vapor, carbon dioxide, and trace levels of ash – the same as paper. It also takes a great deal of heat to make EPS foam burn. In normal situations, it simply melts.

The simple chemical makeup of EPS is carbon, hydrogen, and oxygen – elements found in wood and other organic materials.  EPS foam products do NOT contain formaldehyde.

Both EPS and XPS can be used for insulation and some gas escapes from both types of foam. In EPS foam that gas is air since EPS is made with steam. In XPS that gas is primarily Tetrafluoroethane a dangerous chlorofluorocarbon also used as a refrigerant. (

Yes. Many manufacturers recycle their waste beads and reuse all materials or convert it into other products. The EPS Industry Alliance works closely with the plastics industry to develop recycling techniques and technology that are both efficient and economical. The goal of manufacturers is zero EPS in landfills.

Traditional EPS foam does not biodegrade, it is benign to the environment and provides a stable fill material similar to earth, rock or concrete.

EPS foam will break down in presence of UV light or sunlight. When protected form the sun, such as when used in wall insulation it lasts indefinitely and does not break down as other forms of insulation do.

Our goal is to limit waste construction materials which is why the BuildBlock 1-inch repeating interlock pattern is so important. This means that you will never need to cut off more than 1-inch of foam to maintain connections. Most other ICFs use a much larger pattern and have a greater amount of waste.

EPS foam is one of the longest-lasting, cost-effective, and efficient building materials on the market. Recyclable and non-toxic it can keep our homes and businesses energy efficient for centuries.

Information for this document came from several sources. We always recommend that consumers do their own research and decide for themselves.

Sources Consulted:

Energy Efficiency Explained

Heating and Air Conditioning systems are measured in British Thermal Units per Hour (BTUh). The heat extracted from your home by an air conditioner is measured in BTUs while cooling and heating capacities are referred to in British Thermal Units per hour. For reference, 12,000 BTUh equals one ton of cooling.



The Home Energy Rating System (HERS) Index is the INDUSTRY STANDARD by which a home’s energy efficiency is measured. It’s also the NATIONALLY RECOGNIZED system for inspecting and calculating a home’s energy performance.

See the HERS system explained here:



ENERGY STAR is a government-backed program helping businesses and individuals reduce energy costs and protect the environment through superior energy efficiency.

Developed by the U.S. Department of Energy and the Environmental Protection Agency (EPA) in 1992 to promote awareness of energy-efficient products, ENERGY STAR is a voluntary labeling program. Manufacturers partner with the EPA to label high-efficiency systems with the ENERGY STAR label so homeowners can easily identify those higher-efficiency products that can help reduce greenhouse gas emissions and save energy.

The minimum efficiency required by the EPA for ENERGY STAR recognition includes air conditioner and heat pump units with a SEER of 14.5 or above, 12 EER, or HSPF of 8.2 or above.

The Seasonal Energy Efficiency Ratio (SEER) measures air conditioning and heat pump cooling efficiency. This measurement is calculated by the cooling output for a typical cooling season divided by the total electric energy input during the same time frame. A higher SEER rating means greater energy efficiency.

Like SEER, the Energy Efficiency Ratio (EER) of a cooling unit is determined by the output cooling divided by the electrical power input. However, contrary to SEER which is calculated over a range of outside temperatures, EER is typically determined by a set outside air temperature, a set inside air temperature and a 50% relative humidity. For a comparison point, 11 EER is roughly equivalent to 13 SEER.

The Heating Seasonal Performance Factor (HSPF)  measures the efficiency of the heat pump. The HSPF is a ratio of the heat output to electricity use over an average heating season, and the higher the HSPF the greater the energy efficiency.


The Annual Fuel Utilization Efficiency (AFUE) is a measure of a gas furnace’s efficiency in converting fuel to energy, by projecting the average thermal efficiency for a complete heating season. A higher AFUE rating means greater energy efficiency.