A new guide published by APA – The Engineered Wood Association describes how builders can cost-effectively meet energy code requirements by value-engineering energy efficiency for a whole-home system. Viewing the home as a system means getting more bang for the buck by allocating construction dollars for value, trading out higher-cost energy-efficiency assemblies where they are not necessary.
Today’s energy codes address all major components and systems in a structure, including the building envelope, mechanical systems, service water heating, lighting, and air infiltration. The performance path uses energy modeling to demonstrate the building as a whole uses equal or less energy than a home built to the prescriptive path, which alternatively looks at each component for a specified R- or U-value. The performance path allows flexibility to trade out of many of the high-cost assemblies required in the prescriptive path, while delivering a home that is more energy-efficient as a whole.
While the more recent versions of the International Energy Conservation Code (IECC) require stricter energy efficiency in residential buildings, they also give builders more options for compliance. Builders can implement performance-based options, such as the Energy Rating Index (ERI) and the Simulated Performance Alternative to comply with the code. This can reduce energy use while containing construction costs and maintaining the structural integrity of wall assemblies by using continuous wood structural panel wall sheathing to meet critical structural code requirements.
“Builders should be able to quickly get a handle on the energy impacts of certain assemblies and systems,” said Tom Kositzky, APA Field Services Director. “That way they can confidently engage with their energy rater to get the greatest return for their dollar as they seek to cost-effectively increase energy efficiency.”
Alternative methods, or “paths,” for energy code compliance are identified in the new guide, Performance Path to Energy Code Compliance, Form R505A. The guide is available for free download from the APA website at https://www.apawood.org/energy-efficiency