Making New Energy Codes and Standards Work for Home Builders Through Exterior Continuous Insulation
As the industry evolves, staying ahead of energy standards presents challenges for builders, but it can also be a benchmark for quality and innovation. The of the underscores the key role continuous insulation (CI) can play in new home building projects.
What Are the 2021 IECC Thermal Requirements?
Newer energy codes encourage the use of CI as an option to meet prescriptive (wall) thermal requirements, as well as options for building thicker walls with greater cavity insulation levels. An advantage of exterior CI is that it can allow builders to continue using 2x4 construction vs moving to 2x6 construction and the various design changes, costs and potential loss of square footage associated with that change. Whether building with 2x4 or 2x6 wall construction, exterior CI can also allow builders to use standard batt insulation and avoid using more expensive types of insulation in the wall cavity.
It is estimated that adopting the 2021 IECC will deliver energy savings of at least 10 percent, or 20 percent or more in states where older codes are in place.
Here are five benefits to using CI to meet the new IECC thermal standards, taking advantage of available tax incentives, and leveraging the support of k8’s network of experts to guide your team along the way.
1. ENERGY STAR & Eligibility for 45L Tax Credits
All new dwellings acquired on or after January 1, 2025 seeking ENERGY STAR certification and the 45L tax credit eligibility will need to adhere to ENERGY STAR v3.2, which calls for 2021 IECC thermal requirements. These include heightened insulation requirements that are more difficult to meet without using continuous insulation in most climate zones.
2. Continuous Insulation Provides a Simple & Effective Path for Thermal Compliance
Using exterior CI in any of the climate zones can help simplify the thermal compliance process for many, providing a compliance path while optimizing performance. As a material that is continuous across all structural members and installed over framing, CI can boost the thermal performance of the building envelope and potentially reduce homeowner costs associated with heating and cooling.
For example, adding one inch of Styrofoam™ Brand XPS Insulation to a 2x4 wall with R-13 batt gives you 50% higher effective R-value when compared to a 2x4 with only batt.1
The U-Factor Area (UA) alternative method can also allow builders to meet code compliance through trade-offs between R-values in the roof, wall, window, and foundation rather than the prescriptive method. Using exterior CI can help achieve high UA values when compared to adding more insulation since the effective R-value of the high surface area directly impacts UA.
3. Leverage Tax Incentives to Help Offset Costs
Financial incentives available through the Inflation Reduction Act (IRA) of 2022 can help offset the costs of implementing CI. Builders can take advantage of these benefits through 2032 when choosing to implement upgrades in energy efficiency. In particular, Section 45L of the IRA offers builders tax incentives up to $5,000 per dwelling, which can help cover the cost of adding CI to building envelopes.
4. Continuous Insulation Enhances Building Performance and Homeowner Value
The use of CI in new home building offers additional benefits beyond compliance. Its application can mitigate condensation potential, thus reducing the likelihood of callbacks related to moisture management. The optimized thermal envelope and higher effective R-value can also mean reduced HVAC equipment, less energy usage and thus lower energy bills for the homeowner, leading to significant long-term savings.
5. Work with Experts to Do It Right the First Time
k8 can help builders achieve thermal compliance and high-performance homes with its reputable service and support from , the Building Knowledge Center technical team, and the nationwide channel and distribution partners.
The extensive network of 200+ in-field experts can help you execute design changes with installation training and jobsite support. You can also work with the Building Knowledge Center team on a custom UA analysis and additional technical support. Nationwide channel and distribution partners can help enable consistent, quality material supply across your markets.
For more information on how to implement continuous insulation in your next project and meet 2021 IECC requirements, .
1 Calculations assume 16” o.c. framing and the following material R-values: Interior air film R-0.68; ½” Gypsum R-0.45; 2x4 R-3.71; 2x6 R-5.83; ½” OSB R-0.62; 1” Styrofoam™ XPS R-5.0; Exterior air film R-0.17.
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