When planning the construction of a new building, architects and contractors are required to follow a set of standards called building codes. Building codes are guidelines developed at levels as high as the global scale. The codes are adopted and enforced at the local or state level.
Most people think of building codes as a means to ensure safer buildings, however some code requirements go beyond safety and are aimed at also conserving energy. Energy codes are the standards that direct builders on things like how much insulation to use and where to install it based on a building’s geographical location.
As you design your project, if you’re asking, “Is continuous insulation required by code?”—this article answers that question. Find out how energy code requirements will affect your new construction or remodeling project’s use of continuous insulation.
An Overview of Continuous Insulation Code Requirements
Depending on where your project is located, energy codes will provide a different set of instructions. For example, more insulation is required in colder climates like Alaska as opposed to moderate climates found in the southern half of the U.S. Energy codes divide the country into zones. To understand which set of instructions to follow, you must first identify the zone where your construction project is located.
The U.S. Department of Energy provides a regional map to help you identify your zone and energy codes. Use this, along with the chart, to help you design appropriate building envelopes for your region.
Types of Insulation
Energy codes don’t specify the type of insulation to use. You can use various types of insulation to achieve the appropriate R-value. Insulation is used to reduce heat loss and stabilize the temperature inside your building. In order to be most effective, insulation needs to be continuous. Various materials can be used to create a continuous insulation barrier around your entire building envelope. Types of insulation frequently used in the building envelope include:
Blanket: Flexible rolls or batts used in wall or attic spaces
Rigid: Modular boards used on all faces of the building envelope
Blown-in: Loose-fill material used in walls, attics, and hard-to-reach places
Spray foam: Expands to fill wall cavities and in irregular areas
What is Continuous Insulation?
Continuous insulation means that your insulating material is a constant thickness over the entire surface. For example, adding two-inch thick rigid insulation to the entire surface of your exterior wall will provide a continuous R-value.
In contrast, if you only provide blanket insulation between the studs of a wall, the R-value is broken by the studs, which do not carry the same insulating value as the blanket material. This is a non-continuous application.
Likewise, roof liner insulation that is compressed at purlins on the underside of a metal roof does not function as continuous insulation because it fails to embody a constant thickness.
Why Use Continuous Insulation?
Building codes often incorporate continuous insulation because this method improves energy efficiency by eliminating paths where heat can escape through the envelope. Continuous insulation code requirements aim to increase energy efficiency, which in hand, reduces the owner’s heating and cooling expenses over the building’s lifetime.
Other advantages to choosing continuous insulation for your building envelope include:
An additional layer of moisture protection from water infiltration
Fast and efficient installation methods
Code-compliance in wind and fire resistance
Code Requirements for Continuous Insulation
There are clear advantages to selecting continuous installation for energy efficiency, but is continuous insulation required by code? The answer is yes for some zones, if your local area has adopted the IECC 2021 building code. The 2021 International Energy Conservation Code requires continuous insulation for uninsulated wood frame walls in most climate zones.
Reviewing the IECC table for your climate zone will indicate the amount of continuous insulation required for each part of the building, including:
Uninsulated attic space
Attic Space with existing insulation (3-4”)
Uninsulated floors
Uninsulated wood-frame walls
Insulated wood-frame walls
For example, Kentucky is entirely inside climate zone 4. That means that R15 continuous insulation is required by IECC 2021 for uninsulated wood-frame walls if no other non-continuous insulation is used. Check the table for your location’s continuous insulation code requirements.
Remodeled buildings are not always required to meet the updated energy codes. However, before beginning a remodel project, always check with local authorities to see whether your renovated building will need to be code compliant.
Rmax Can Help You Pick the Right Insulation
Figuring out code requirements and picking the right insulating system for your project can quickly become an overwhelming headache. Let the insulation experts at Rmax help. Our representatives can review the R-value requirements, check out your design, and pick out a system of products that meet your project’s demands. Reach out to your local Rmax representative today to get your project moving!