Air and Moisture Barriers Important to Net Zero Homes

vapor barrier for net zero ready homes

Over the past decade, net zero homes have grown in popularity. They are also more viable as solar panels have dramatically decreased in cost while increasing in efficiency, and energy storage systems have become far more cost-effective. Now, the National Association of Home Builders (NAHB) cites a report from the Net Zero Energy Coalition (NZEC) stating that 6,200 housing units in the U.S. and Canada enjoy “zero-energy ready” status.

According to a standard embraced by the NZEC, zero-energy ready structures are those that supply a minimum of 90 percent of their own annual energy requirements. The report suggests that 100 percent zero-energy ready performance is still rare, with about nine percent of the zero net energy housing units identified by the NZEC achieving that level. Another four percent of the housing units actually produce more energy than they consume on an annualized basis.

Typically, on-site generation of excess renewable energy from solar, wind, geo-thermal and biomass installations offsets the building’s overall use of non-renewable energy. Zero-energy ready (ZNE) status means that a building is capable of generating as much energy as it consumes once all renewable energy systems are fully installed.

California and the Northeast Leading in Energy-efficient Homes

According to a report in the news blog of the NAHB, 46 percent of the homes currently classified as zero net energy structures are in California. There, special energy initiatives and abundant sunshine have driven demand for net-zero homes. At the same time, extremely energy-efficient homes have gained real traction in the northeastern United States. For example, the NZEC report identifies 783 zero-energy ready units in New York, Connecticut and Massachusetts.

Energy Savings and Reduced Emissions

The appeal of zero net energy structures is clear. First, they generate ongoing energy savings for property owners. Second, by reducing the use of energy generated from traditional power plants, ZNE buildings reduce greenhouse gas emissions. Although they often consume some power off the grid, they also return similar amounts of power to the grid at other times. With approximately 40 percent of total fossil fuel use in the United States consumed by traditional structures, the appeal of ZNE buildings is real and lasting.

Cosella-Dörken in Net Zero Construction

Dörken is an ally in the pursuit of the net zero ideal in commercial and residential construction. The permeability and air-tightness of their DELTA®-VENT SA make it an ideal choice in energy-efficient construction. DELTA®-VENT SA significantly exceeds Air Barrier Association of America (ABAA) standards, based on ASTM E2357 tests.

This triple-ply air and moisture barrier features two outer layers of high-strength spun-bonded polypropylene fabric. The middle layer is a vapor-permeable yet watertight polymeric membrane. A high-tack adhesive is applied to the entire surface of the lower layer. A split-release liner facilitates installation.

DELTA®-VENT SA is a superior air/moisture barrier for a number of reasons. The membrane eliminates leaks at fasteners thanks to the full adhesion design. It also offers the security of a self-adhesive overlap. DELTA®-VENT SA is also a watertight product providing important protection from wind-driven rain. At the same time, the three-ply membrane allows moisture to pass from the building enclosure via diffusion, addressing the need for breathability.

DOE Promotes Zero Net Energy Construction 

The U.S. Department of Energy (DOE) has been recognizing builders for their energy-efficient construction since the federal agency’s Builders Challenge Program began in 2008. Since then, 14,000 homes associated with the program have generated millions of dollars in current and future energy savings. An independently certified U.S. Department of Energy ZNE home is a proven success when it comes to energy savings, durability, health and comfort.


Dörken delivers innovative, high-performance air and moisture barriers for commercial and residential construction sold under the DELTA® brand name. A North American manufacturer based out of Beamsville, Ontario, Dörken Products, Inc. is a subsidiary of Ewald Dörken AG, a leading European developer and manufacturer of waterproofing and drainage products sold worldwide. Dörken is known for delivering premium products while providing educational programs and full technical support. For more information, call 1-888-4DELTA4 (433-5824) or visit