TA-23-C035 – Advancing Thermal Envelope Measures to Create a Foundation for Decarbonized New Construction

Building energy codes have a tremendous impact on our building stock as they set the course for each building’s lifetime energy, carbon, and lifecycle impacts. Although a code may only be the standard for as few as three years, new buildings following its rules will be impacted for the life of each system designed under it, ranging from 15-25 for most mechanical and water heating systems, and upwards of 50 years for building envelope systems, well beyond the time horizon set by state and local governments with ambitious climate goals. Advancing energy codes beyond the “business-as-usual” (BAU) progression toward passive house levels can significantly reduce carbon emissions and energy costs across the new construction cohort from today onward. Based on data from a cold climate code optimization and development process, this paper will present the energy and carbon impacts of code progression in two cases: BAU vs rapid advancement to passive house envelope levels. The authors will provide a comprehensive analysis quantifying the lifecycle cost, GHG emissions, and grid-scale impacts of rapidly advancing energy codes to passive house envelope levels by 2030 with significant electrification. Compared to the business-as-usual code adoption, direct and indirect emissions from new construction can be cut by as much as 43% and reduce operating costs by almost 5% while increasing incremental peak summer load on the grid by just 2% and initial construction costs by just over 1% on average prior to incentives. These results create a compelling case for states and jurisdictions to adopt an accelerated pathway toward advanced thermal envelope levels of performance in their energy codes. The paper will present how these measures can be incorporated into codes such as the IECC and 90.1 for advancement to stated 2030 goals, and present recommendations for the adoption of advanced envelope measures in other applications such as utility program design and local policies to advance carbon neutrality policy goals.