Home under construction

Ask Randy Williams what is the most important thing in a high-performance building envelope, and you’ll get a simple one-word response.

“Continuity,” says Williams, a residential energy auditor in Grand Rapids, Minn.

In other words, no thermal gaps.

That’s where continuous insulation (CI) comes in.

CI is comprised of rigid foam boards or mineral wool and is installed on the exterior of the sheathing. This provides a consistent thermal barrier with a high R-value to minimize where heat escapes through structural elements like studs.

And, yes, heat escapes through studs. The rolled insulation in the cavities of the frame does little to prevent thermal bridging.

“When I’m doing an energy audit, I’ll take my thermal imaging camera and one of the things that you’ll notice is every framing member stands out like a sore thumb,” Williams says.

Modern building codes demand lower HERS scores — that’s the Home Energy Rating System — and CI can be a key contributor helping builders meet stringent standards.

The results are threefold:

Improved energy efficiency: By reducing thermal bridging and enhancing airtightness, CI significantly lowers energy consumption for heating and cooling.

Better indoor air quality: A well-insulated and airtight envelope prevents outdoor pollutants and allergens from entering the home, contributing to healthier indoor environments.

Cost savings: While the initial investment in advanced envelope systems may be higher, the long-term savings on energy bills make CI a worthy investment.

But in Williams’ view, lowering a home’s operational costs is not the only, or even the primary, reason to use it. There’s another benefit that’s often overlooked.

“Adding durability and longevity to a structure is why I include CI,” Williams says.

Keeping the building envelope warmer reduces the risk of moisture accumulation and mold growth, thereby prolonging the lifespan of building materials. Put simply: “A dry building will last longer,” Williams adds.

But not all CI products defend against moisture. That’s why Williams specifies CI made of expanded polystyrene (EPS) or graphite polystyrene (GPS), which is more water resistant compared to common alternatives. In field tests conducted by Henry, EPS and GPS demonstrated less water absorption, allowing it to maintain its high R-value.

There are also newer products on the market Williams has been moving toward that integrate CI and a WRB. There is a new integrated panel the combine a WRB and Continuous Insulation into a single-step product, saving time and improving the performance of the home.

There’s also the convenience factor to consider. Because this material serves double duty as both a thermal barrier and a moisture shield, installation is streamlined.

“One trip around the home and you’ve both insulated and installed the water-resistive barrier,” Williams says.

In an industry grappling with a labor shortage, that matters.

“Anytime we can simplify the construction process, it’s a win for everyone,” he adds.

Henry Blueskin VPTech combines a weather -resistive barrier (WRB), continuous insulation (CI), and seam sealing in a single, integrated panel, significantly improving energy efficiency, and reducing installation time and associated labor costs by up to 30%. Blueskin VPTech can help lower a home’s HERS® (Home Energy Rating System) Score and contribute to ENERGY STAR and Zero Energy Ready Home (ZERH) program requirements. Click here to learn more.