How PermaBASE CI meets continuous insulation needs and more

This blog post was originally published on September 6, 2022 and updated on July 15, 2026 with new information, enhanced content and additional resources.

Using exterior continuous insulation is a proven method for meeting ever more stringent green building standards and R-value requirements for residential, multifamily and commercial construction. PermaBASE CI® Insulated Cement Board helps contractors achieve the energy rating they need while also providing a substrate that is ready for exterior veneers.

What is exterior continuous insulation?

Exterior continuous insulation is insulation installed on the outer side of the wall studs to prevent thermal bridging through framing members. As an uninterrupted thermal barrier covering the entire building envelope – including around structural elements – continuous insulation improves the overall energy efficiency of the building by reducing heat loss or gain. It helps maintain more consistent indoor temperatures and can improve moisture management by keeping wall assemblies warmer, thus reducing the risk of condensation.

In 2022, greenhouse gas emissions from U.S. homes and businesses accounted for 31% of the nation's total output, according to the U.S. Environmental Protection Agency. Because an individual or business’s carbon footprint is defined by the sum of these direct and indirect emissions, improving building performance is essential. By utilizing exterior continuous insulation as a cost-effective strategy to boost energy efficiency, companies can meaningfully shrink their carbon footprint and more effectively reach their sustainability goals.

How does exterior continuous insulation work?

If you have ever zipped up a puffer jacket before stepping outside on a winter’s day, you are effectively wearing exterior continuous insulation. The loft of the jacket creates an air barrier that keeps the warmth inside. It works the same way for buildings and homes: By reducing thermal bridging to only the fasteners used to attach it to the structure, exterior continuous insulation creates a nearly unbroken barrier.

What is the difference between cavity insulation versus continuous insulation?

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings defines continuous insulation as, “insulation that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.”

Traditionally, in framed wall construction, cavity insulation fills wall cavities in between metal or wood wall studs. The studs create a connection between the exterior and interior cladding and can cause thermal bridging, which is the transfer of heat through a material. Thermal bridging reduces the effectiveness of the insulation.

Since studs make up roughly 25% of walls in a typical building, thermal bridging can reduce the insulation efficiency by roughly the same percentage.

How does exterior continuous insulation improve energy efficiency?

Exterior continuous insulation enables the building’s heating and cooling system to operate more efficiently by preventing heat from escaping through framing members in the winter or entering through framing members in summertime, a process known as thermal bridging. HVAC efficiency not only provides long-term cost savings on utility bills, but it also contributes to a smaller carbon footprint.

How does exterior continuous insulation help meet energy codes?

ASHRAE 90.1 sets minimum requirements for energy efficient designs for buildings. It has been updated six times since 1975 to reflect new building materials and technologies. The International Energy Conservation Code references this standard, and many states have adopted an edition of ASHRAE 90.1 into state energy codes.

ASHRAE 90.1 requires continuous insulation for all commercial and some residential buildings. The amount of insulation is determined by the climate zone where the building is located. Adding continuous insulation on the outside of the building — in addition to inside the stud cavity — significantly reduces thermal bridging.

The United States is a patchwork of different codes because energy codes are adopted at the state level. However, there is a general trend of states adopting more stringent energy codes to reduce energy consumption and carbon emissions.

What are the continuous insulation R-value requirements by energy code climate zone?

One of the most critical factors driving the evolution of the exterior wall assembly is the stringent adherence to modern energy codes. A consistent, continuous insulation R-value across the entire wall assembly reduces energy loss through structural elements.

R-values reflect how well the insulation keeps heat from leaving or entering the building or home, and higher R-values indicate better insulating effectiveness. With traditional insulation, building designers must calculate the R-value reduction from thermal bridging. By using exterior continuous insulation, they can use the full R-value listed on the package of the continuous insulation product they select.

The specific continuous insulation requirements vary significantly depending on the regional climate zone, which correlates directly to heating and cooling demands. Architects and builders must consult the adopted version of the International Residential Code (IRC) or International Building Code (IBC) in their jurisdiction, as the minimum required R-value for exterior insulation can change with each code cycle.

The table below shows the minimum required continuous insulation R-value defined by the eight major U.S. Climate Zones and based on the most common model energy codes.

PermaBASE CI Insulated Cement Board is designed to simplify compliance with these requirements by combining the sheathing and required continuous exterior insulation into one component. With available insulation thicknesses that deliver R-values from R-4 to R-22, these composite boards offer a convenient solution for meeting or exceeding the mandate of most jurisdictions.

What is PermaBASE CI Insulated Cement Board?

PermaBASE CI Insulated Cement Board is a composite cement board laminated with rigid polyiso foam insulation to help meet energy codes, provide a durable substrate for a variety of exterior finishes and add a code-compliant, highly fire-resistant component in NFPA-tested assemblies.

PermaCASE CI was developed for use on building exteriors to help attain energy code requirements for continuous insulation, while also providing a substrate that saves time and materials in the installation of exterior adhered veneers.

Benefits of PermaBASE CI Insulated Cement Board

Use PermaBASE CI to meet or exceed most exterior continuous insulation requirements.

• Meet energy code requirements – Choose from four thickness options for a variety of climates: 1" with an R-4 rating for use in warmer residential climates, 1-1/4” with an R-6 for warmer commercial climates, 2" with an R-10 rating for temperate areas and two options for colder locations: 3" with an R-16 rating and 4" with an R-22 rating. Learn how PermaBASE CI simplifies mixed-material veneer facades to meet energy codes.
• Create a durable substrate for a variety of exterior finishes – A single, solid substrate simplifies veneer application, whether you’re using thin brick, stone, stucco or tile.
• Included in NFPA 285–tested assemblies – As a highly fire-resistant product, it is NFPA 285 tested and approved for use with adhered veneer finishes such as manufactured and natural stone, thin brick and tile, as well as direct applied coatings of synthetic stucco.

Use PermaBASE CI to meet or exceed most exterior continuous insulation requirements.

• Meet energy code requirements – Choose from four thickness options for a variety of climates: 1" with an R-4 rating for use in warmer residential climates, 1-1/4” with an R-6 for warmer commercial climates, 2" with an R-10 rating for temperate areas and 3" with an R-16 rating for colder locations.
• Create a durable substrate for a variety of exterior finishes – A single, solid substrate simplifies veneer application, whether you’re using thin brick, stone, stucco or tile.
• Included in NFPA 285–tested assemblies – As a highly fire-resistant product, it is NFPA 285 tested and approved for use with adhered veneer finishes such as manufactured and natural stone, thin brick and tile, as well as direct applied coatings of synthetic stucco.

Model codes created by the International Code Council (ICC) and the National Fire Protection Association (NFPA) reference NFPA 285 as the test standard for exterior wall assemblies.

The NFPA 285 test method evaluates how flames spread on an exterior wall assembly subjected to fire. It simulates a two-story wall assembly with an opening for a window on the first-story wall and a floor assembly separating the two rooms.

NFPA 285 assesses flame growth in the following ways:

• Over the exterior wall surface
• Within the combustible core or components
• Over the interior surface from one floor to the next
• Laterally to adjacent compartments

PermaBASE CI Insulated Cement Board combines a durable, highly fire-resistant cement board with energy-efficient, high-density polyiso insulation into one exterior continuous insulation product to help meet both energy and fire code requirements.

How can PermaBASE CI Insulated Cement Board save installation time and money?

PermaBASE CI Insulated Cement Board plays a dual role by providing insulation and a ready-to-go substrate onto which the exterior veneer or stucco can be installed. The following features help this insulation solution stand apart from its competition:

• Ready-to-go substrate for stone, brick, tile and stucco
• Easy-to-cut construction
• Insulation and exterior cladding installed in one step

The time and cost savings from PermaBASE Cement Board are well documented. See how PermaBASE CI simplifies installation with our commercial thin brick and commercial stucco wall system installation video below.

Watch our step-by-step demonstration of how to use PermaBASE CI® Insulated Cement Board to install a thin brick wall system.

Learn how to install a stucco wall system with PermaBASE CI® Insulated Cement Board in this step-by-step video.

Exterior continuous insulation plays a crucial role in enhancing energy efficiency, optimizing thermal performance and meeting stringent code requirements. PermaBASE CI Insulated Cement Board enhances these benefits by combining high-performance insulation with a durable, versatile substrate.