Orchard Knoll

Challenge

To minimize air leaks through exterior walls, the Orchard Knoll neighborhood had been using loose-laid house wrap with taped seams over oriented strand board (OSB) sheathing, then covered that system with an R5 rigid exterior insulation board. This combination system was effective in meeting their energy-efficiency goals and qualifying for builder rebates through a local energy provider, but was expensive, labor-intensive and redundant. They were looking for a solution that would provide equal or better air control, at lower overall construction costs.

Solution

Orchard Knoll elected to replace the house wrap and exterior insulation board system on a test home with the EnviroDri® Weather-Resistant Barrier System from Tremco Barrier Solutions. The fluid-applied EnviroDri System is code-approved as both a moisture- and an air-barrier. One of the key benefits of EnviroDri that intrigued Orchard Knoll was that the system effectively and permanently sealed the home envelope from the outside, reducing air movement and rendering the two-step and expensive house wrap and exterior insulation process unnecessary.

On similar homes, the EnviroDri WRB significantly contributed a 50% reduction in air changes per hour (ACH) as compared to the control home, which used the standard house wrap and exterior insulation system. By reducing the ACH from 3.64 to 1.8, Orchard Knoll was able to generate a HERS® index of less than 60, which is at least 40% more energy-efficient than the reference home. Additionally, the lower HERS index qualified Orchard Knoll for higher energy rebates from the local utility company.

Today, every home built by Orchard Knoll is designed, marketed and sold with the EnviroDri Weather-Resistant Barrier System as the standard for air and moisture control . . . providing their buyers with the great home they want, at an extremely high value for the dollar.