Mastering Building Envelopes—A Simple Hack for Code Compliance and Efficiency

Guest Blog by Randy Williams, President, Wilcon Inc.

The construction industry is changing rapidly as energy codes evolve to demand greater efficiency and sustainability. In my work, I’ve seen the challenges builders face in adapting to these new standards, especially as we move from the 2021 energy code to the stricter 2024 updates. Understanding these codes and finding practical ways to meet them is crucial for staying ahead in this field.

Simplifying Energy Code Compliance

Meeting the 2021 Energy Code often comes down to two main pathways:

1. The Prescriptive Pathway: This is the simplest approach, a “cookbook” method that lays out specific R-value and U-factor requirements for walls, ceilings, and other building assemblies.
2. The Performance Pathway: This more flexible option involves advanced modeling software and third-party evaluations, allowing for creative trade-offs and innovative solutions to meet code requirements.

Each pathway has its strengths, but I find that the choice often depends on the specific project and its climate zone requirements.

The Power of Continuous Exterior Insulation

One strategy I always recommend is continuous exterior insulation. It’s like putting on a jacket to stay warm—logical and effective. By applying insulation on the exterior of a building, thermal bridging is minimized, and the overall efficiency of the wall assembly improves. Products like Henry Blueskin VPTech integrate water resistance, air barriers, and insulation into a single system, saving time and labor while ensuring code compliance.

Focusing on the Four Control Layers

Durability and efficiency in construction start with mastering the four key control layers:

• Water Control: Keeping water out of assemblies is the top priority. Proper drainage, roof overhangs, and water-resistive barriers ensure bulk water is managed effectively.
• Air Control: Reducing air leakage not only improves energy efficiency but also enhances indoor air quality. Materials like Blueskin or ZIP System Sheathing work well here.
• Vapor Control: Misunderstandings about vapor barriers can lead to problems like trapped moisture, which is why assemblies must allow drying in at least one direction.
• Thermal Control: Prioritizing continuous insulation over traditional cavity insulation keeps homes more comfortable and energy-efficient.

Preparing for 2024 and Beyond

Looking ahead, the 2024 Energy Code is set to introduce even tighter air-sealing metrics and new insulation standards for unheated slabs and roof decks. For example, air tightness in colder climates will need to improve from 3 ACH50 to 2.5 ACH50. Adapting to these changes requires not only familiarity with the code but also a willingness to embrace innovative building strategies and materials.

Making It Work

For builders, it’s about balancing costs and compliance. Continuous insulation and products like Blueskin VPTech simplify the process, combining multiple functions—water resistance, air barriers, and insulation—into a single application. It’s a practical way to reduce labor while meeting the stringent requirements of modern codes.

These energy codes aren’t just about ticking boxes—they’re about creating homes that are durable, efficient, and comfortable for generations. By focusing on sound building science principles, I believe we can meet these goals while staying competitive in the industry.