An insulating concrete form (ICF) system uses hollow blocks made of polyurethane or polystyrene foam to form the foundation walls or even the whole house.

How it works

The foam blocks are fitted together like puzzle pieces or secured using C-shaped channels. Installers reinforce the forms with steel rebar, then fill the hollow chambers with concrete.

Electrical and plumbing lines are concealed within carved channels cut into the foam walls. Both the interior and exterior can be covered with any type of finishing product, including drywall, plaster, brick, stucco or siding.

Energy savings

The insulation value of a finished wall ranges from R-18 to R-26, and the solid concrete core virtually eliminates the cold drafts typical of wood-frame construction. This means most ICF homes have utility bills 30 percent lower than typical homes.

Other benefits

A typical four-inch-thick foam block wall is four to six times stronger than a conventional "stick-built" house, making it resistant to fire, violent winds and even earthquakes. In some areas, owners of foam-block houses may qualify for lower home insurance premiums.

The combination of high-mass concrete and permanent insulation will also reduce noise pollution, resulting in a quieter home.

Costs

The construction costs for ICF houses usually runs about five to seven percent more than wood framing, but the costs can be paid back in energy savings in two or three years.

More from this category

Decoding building requirements

house blueprints

Learn about some of the changes for new homes built today. An expert highlights some of the things to consider when building a new home.

learn more

Habitat for Humanity

Volunteers joining hands

Habitat for Humanity is an organization that provides simple, sturdy homes. Learn how energy efficiency is a key factor in building these homes.

learn more

Framing options

Man installing steel framing

You have energy efficient and sustainable options when it comes to framing your new home.

learn more

Geodesic domes

Geodesic dome home

A geodesic design uses interconnected triangles to create a strong, environmentally friendly structure.

learn more

New home comfort issues

Graphic of heating and cooling circulating through a house

Our four-part series explores how to handle comfort issues in a new home.

learn more

Energy rater and performance consultant

Energy rater performing analysis on a front door

An energy rater can help make your new home more energy-efficient through every stage of the construction process.

learn more

Air quality and ventilation in new homes

Man showing ductwork to Pete and Megan

New, energy-efficient homes need new solutions to circulate and ventilate the air inside the home.

learn more

Aging in place

Adjustable height kitchen sink

Using universal design principals, your home can adapt to your changing lifestyle needs.

learn more

Historic preservation

Boy and grandmother on front porch

A preservation expert shares how to restore an older home economically and energy efficiently.

learn more