TOWARD 2020: THE ROAD TO ZERO NET ENERGY
The complementary voluntary rating and labeling systems that build upon the latest codes provide the housing industry with an easy path to zero-net-energy-ready homes. This begins with Energy Star-certified homes that ensure a comprehensive building science system. Mandatory requirements include complete thermal enclosures, quality installed HVAC systems, and complete water protection.
Indoor air quality is no longer extra credit. Airtight, well-insulated homes need to fully address source control, dilution (e.g., whole-house and spot ventilation), and filtration. EPA’s Indoor airPLUS meets this challenge with comprehensive requirements addressing moisture control, radon, pests, combustion pollutants, and safe materials.
The DOE Challenge Home provides a simple label for identifying ultra-efficient homes that meet and exceed forthcoming energy codes while delivering zero-net-energy-ready performance. This includes proven innovations from the Building America program, Energy Star–certified components throughout the home, comprehensive indoor air quality requirements from Indoor airPLUS, and renewable energy–ready measures that can save thousands of dollars installing future solar energy systems. Currently, comprehensive water conservation, disaster resistance, and quality management are encouraged, but they are likely to be required in future versions of the Challenge Home specifications.
As these rating and labeling programs gain traction, they can help inform incremental code changes based on their house-as-a-system specifications. This interrelationship is already under way with Building America research innovations providing technical underpinnings for Energy Star–certified homes and DOE Challenge Home specifications, which in turn influence regulatory code changes.
As an example, thermal enclosure air barrier guidance developed with Building America research became part of the DOE Challenge Home (formerly known as Builders Challenge) before being applied as the Thermal Bypass Checklist in Energy Star for Homes Version 2 specifications, and then ultimately adopted in the 2009 IECC. This market transformation process between codes and rating systems needs to further address all of the high-performance home rating systems currently in play.
We have a vision: All new homes by 2020 will be zero-net-energy-ready homes that are affordable, efficient, comfortable, healthy, and durable. Codes, standards, and rating systems fueled by investments in research and development are critical components that can drive the market transformation process and get us to that goal. Building America is serving as an effective hub of innovation for the housing industry. A wide array of rating and labeling programs are providing the market with great tools for recognizing and choosing innovation. And the model energy codes are impressively increasing in stringency. The key challenge now is to make sure a comprehensive systems approach is applied every step of the way.
Sam Rashkin is the chief architect at the U.S. Department of Energy’s Building Technologies Program.