Worker installing cavity insulation between interior and exterior brick walls.

At relatively low cost, insulation results in lower utility bills, while keeping out moisture and improving air quality.


Reduce SourcesElectricityEnhance Efficiency
Reduce SourcesBuildingsEnhance Efficiency
CO2 Equivalent
Reduced / Sequestered
Billion $US
Net First Cost
(To Implement Solution)
Trillion $US
Lifetime Net
Operational Savings
Insulation impedes unwanted airflow in or out of buildings. In new construction or retrofits, it makes heating and cooling more energy efficient, with lower emissions.

Solution Summary*

Heat always moves from warmer areas to cooler areas, until a temperature equilibrium is reached. This heat flow presents a central challenge when keeping buildings within a desirable range of 67 to 78 degrees Fahrenheit. To close the gap on unwanted heat gain or loss and maintain comfortable room temperature, we use more energy. Air infiltration accounts for 25 to 60 percent of energy used to heat and cool a home—energy that is simply wasted.

By better insulating a building envelope, heat exchange can be reduced, energy saved, and emissions avoided. What makes insulation effective is its capacity for thermal resistance, measured as R-value—the higher the better. Ideally, a building’s thermal layer should cover all sides—bottom floor, exterior walls, and roof—and be continuous. Sealing gaps and cracks is also critical to a more effective building envelope.   

Insulation is one of the most practical and cost-effective ways to make buildings more energy efficient—both in new construction and through retrofitting older buildings that often are not well encased. At relatively low cost, insulation results in lower utility bills, while keeping out moisture and improving air quality.

* excerpted from the book, Drawdown

Retrofitting buildings with insulation is a cost-effective solution for reducing energy required for heating and cooling. If annually, 1.6-2 percent of existing residential and commercial buildings in temperate and tropical countries install insulation increasingly with low carbon materials, 17-19 gigatons of emissions can be avoided at an implementation cost of $751-831 billion. Over the lifetime of the building, heating and cooling savings could be $21- $24 trillion.