How Six-Sided Wall Assemblies and Updated Building Codes Can Change Everything

Across the United States, residential and commercial buildings account for nearly half of the nation’s energy consumption annually, the U.S. Department of Energy said. Those same buildings – which cost about $400 billion a year to heat, cool, power and light – are responsible for 35% of the nation’s carbon emissions, the DEP found.

Today, policymakers, builders, contractors and property owners alike are exploring new ways to cut costs and reduce energy output. They’re turning to modern solutions – improved building codes and six-sided wall assemblies – to make significant changes.

Since the 1970s, building energy codes have been used in the United States to reduce costs, cut carbon emissions and implement climate-friendly standards for the future of construction. Every three years, the International Code Council (ICC) updates its code models (called I-codes), including the International Building Code (IBC), International Residential Code (IRC) and International Energy Conservation Code (IECC).

I-codes are used as a foundation for regional codes that guide decisions for sustainable and resilient building to meet local needs. In the past few years, local and state lawmakers have been shoring up building codes with a greater focus on efficiencies, indoor air quality and reducing the impact of building emissions. Consider what’s in the works:

• New York City’s Local Law 97, which passed in 2019 with requirements beginning in 2024, limits greenhouse gas emissions from most buildings larger than 25,000 square feet, with an ultimate goal of reducing carbon emissions by 40% by 2030 and 80% by 2050.
• Colorado’s House Bill 22-1362, passed in May 2022, requires local governments to adopt more stringent, climate-friendly building codes for new construction buildings and homes. In the coming years, local jurisdictions will be tasked with writing the codes.
• Maryland’s Climate Solutions Now Act established building energy performance standards and requires some commercial and residential structures to achieve net-zero emissions by 2045.
• Bloomington, Ill., homeowners can take advantage of the Bloomington Green Home Improvement Program, which provides some households with low-interest loans for improvements that include building envelope retrofits.

For builders and developers, new codes are also an opportunity to improve building envelope performance. The use of six-sided wall assemblies is more common now as a means to gain performance and improve comfort for those living and working in buildings.

For decades, builders and developers prepared traditional four-sided wall assemblies with mass insulation alone. But little was done to stop air flow, and absence of an air barrier allowed for heat and moisture transfer, even with insulation between the studs.

Building scientists now know focusing on the six-sided cavity — the roof, foundation and four walls – is more effective. That is, mass insulation and an air barrier abutting on all six sides of the building envelope including any interior walls adjacent to unconditioned space provide greater thermal control. A six-sided wall, ceiling or floor assembly using an air barrier not only lowers energy costs, reduces HVAC wear and tear, increases moisture control and improves indoor air quality (IAQ), but also creates more comfortable indoor living conditions.

Sam Rashkin, the former chief architect for the DEP’s Building Technologies Office, said an air barrier coupled with mass insulation is like wearing a water-repellent jacket and a sweater on a cold, windy day. The cold wind and moisture easily move through the sweater without the jacket. But the waterproof jacket and sweater together stop the cold and wind. The jacket acts as an air barrier for adequate thermal protection.

Wall assemblies, particularly ones that face unconditioned spaces like attic knee walls and plumbing chases, need air barriers that meet specific needs. Take, for example, FI-FOIL’s SkyFlex™ , which provides air barrier control in dry and humid conditions in any climate.

Unlike rigid foam board, SkyFlex™ incorporates two low-e aluminum layers with a layer of woven polyethylene to create a resilient and flexible air barrier. The Low-e surfaces provide added thermal performance by reflecting heat rather than absorbing it. As a Class I vapor retarder, SkyFlex™ keeps walls dry to reduce the chances of moisture accumulation.

• Less air infiltration for a more efficient, healthier building
• Reduces up to 96% of radiant heat transfer
• Durable and flexible, installs 2x faster with fewer joints to seal
• Easy-to-handle 500-square-foot rolls which minimizes risk of damage to material on jobsite
• One roll of Skyflex™ equals 16 sheets of rigid foam board
• Adds R-value to a building envelope

• Easy-to-handle continuous rolls
• Strong, flexible and lightweight (10 pounds per roll) for easy installation
• Wide rolls for fewer seams and air gaps
• Installs 2x as fast rigid air barriers
• Puncture resistant
• Reduces radiant heat transfer

• Improved energy efficiency
• Savings on utility bills
• Reduces wear and tear on HVAC systems
• Greater indoor comfort using less energy
• Improves indoor air quality
• Increases thermal protection
• Peace of mind that comes with protection from weather extremes

For Rashkin — who launched the national Energy Star Certified Homes and Zero Energy Ready Home (ZERH) programs – a sustainable future involves energy-efficient buildings and a move to zero-energy homes and commercial spaces. All facets of building construction – from the development of building energy codes to sealing a six-sided cavity – are essential to reducing carbon emissions. Today’s consumers understand the value of net-zero builds in both dollar signs and energy savings, Rashkin said.

“I think builders understand that this is a new world, that the informed buyer does change everything,” he said. “If you’re going to be relevant, you’re going to have to be a net-zero builder.”

For more information about FI-FOIL’s SkyFlex™, contact FI-FOIL® today at FiFoil.com or (800) 448-3401.