Energy savings from using insulated concrete forms in new construction comes from the fact that they are superior in strength, productivity and energy efficiency. The energy efficiency upgrades when using ICF stem from both the EPS (expandable polystyrene) insulating panels as well as the core concrete that “fills” the interior of the walls. This design has other advantages such as soundproofing and the ability to withstand damage from the most extreme disasters but it’s the reduced labor costs, speed in production, structural strength and energy efficiency that offer savings immediately.
Improving energy efficiency can be boiled down to one simple statement – cutting out energy loss. A traditional wood frame home – no matter how tightly constructed – is basically an air loss liability. Almost every feature of interior and exterior construction will start to leak air over time including walls, windows, doors, floors, and more.
Insulated concrete form construction gains energy efficiency advantages by avoiding these traditional air loss areas, creating the most airtight building envelopes in today’s industry. ICFs excel in every element in a building:
- Walls – ICF walls are insulated with EPS foam on each side and have a poured in place concrete core sandwiched in between. This creates a much more reliable thermal barrier than wood sheathing and batted insulation creating of up to 40%+ energy saving in comparison to traditional framing.[1]
- Windows – Glass is glass which will always be a heat and cool loss risk. That being said double or triple paned windows with insulated gas can help cut that loss. In addition ICF manufacturers offer foam window buck that make the insulation continuous into the window frame. This helps with ease and speed of creating window openings and offers more energy retention.[2]
- Doors – The use of insulated concrete form walls creates a tighter seal around doors than traditional wood framing. Again, a foam buck system can be utilized around door openings. This also helps keep moisture out around areas that are usually vulnerable to moisture penetration.[3]
- Floors and Ceilings – There are many options for composite floor systems that marry well with ICF construction. Some of them have EPS foam and are filled in with concrete,[4] while others utilize steel joists and metal decks that retain a 2-3” concrete slab.[5] By using composite floors or roofs for a home, energy loss can be reduced by 15%-18% compared to wood frame floor and ceiling construction.
The increased energy efficiency can be found in all areas of construction when choosing innovative materials. For example, insulation values for ICF walls (which offer a stay in place, rigid insulation) range from R-30 to R-60 depending on the block’s core size, whereas wood framing tops out at around R-19 even with added insulation. The savings by choosing ICF are noticed by homeowners and developers that use them globally. When large commercial buildings are compared to similar structures built out of wood the savings are immense. The graph below shows a number of schools in a district and their individual energy use. The Suter school is the first ICF school built in this region. While the district average fluctuates between 0.055 and 0.075 throughout the year, the Suter school stays constant below 0.03. This shows the real savings associated with reducing energy use by about 50% because of ICF.
The increased energy efficiency of using ICF construction has allowed insulated concrete forms to be the preferred building choice of developers and homeowners. In fact, energy efficiency is only one of the reasons why ICF is considered the future in sustainable building.
[1] http://buildblock.com/icfs/energy-savings/
[2] http://www.foxblocks.com/products/icf-accessories/fox-buck/
[3] http://buildblock.com/products/buildbuck/
[4] http://www.insul-deck.org/
[5] http://www.ispansystems.com/systems/masonry/
