The National Home Builders Association (NAHB) estimates that at least 17% of all new homes are built with shared walls. Despite the benefits of these walls, they present challenges that impact building performance. Read on to discover three ways common walls can affect your build.
Energy efficiency
When testing EPS homes that are at least 10% above the 2021 Oregon Residential Specialty Code (2021 ORSC), a significant difference was found in air leakage between detached homes and homes with common walls. EPS homes with common walls have 23% more air leakage compared to detached EPS homes. This increase in air leakage can:
- Compromise homeowner comfort
- Increase energy bills
- Reduce indoor air quality
- Jeopardize incentives, tax credits and code compliance
Fire suppression
The 2023 ORSC requires a two-hour fire rating for common walls. Construction practices and materials necessary to achieve a two-hour fire rating do not address all air sealing requirements, which can result in adverse energy outcomes, including heat loss, heat gain and reduced airtightness. For example, fibrous insulation is an effective fire blocking material, but it does not effectively air seal the wall assembly.
Sound control
Sound travels more easily between homes with common walls because of the proximity and the shared structural elements between two units. That makes sound control especially important for common walls, with privacy between units a priority. Specialized sound-dampening materials are necessary to address sound control, but they must be implemented thoughtfully to also have a positive—rather than negative—impact on air leakage control and thermal performance.
Plan ahead: Contact an EPS verifier
Building a home with common walls? Contact your EPS verifier to see how you can increase building performance and boost incentives.
Our trade ally coordinator is also available via email or phone at 1.877.283.0698 for any questions about the EPS New Homes program.