Calculating Fenestration System U-Factor, SHGC, and VT Using Partially Automated Workflows

This paper explores current workflows and methodologies used by building enclosure professionals to calculate and report the effective U-Factor, Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT) of fenestration assemblies, henceforth referred to as fenestration performance metrics, in various stages of design. Topics covered include a review of manual and partially automated calculation and simulation workflows, as well as methods for communicating performance targets and goals with the project team, including a web-based data visualization tool developed by the author’s firm.
This paper relies on shared modeling experience informed by building enclosure design and consulting as the basis of the discussion. While multiple means for calculating and reporting fenestration performance metrics exist, this paper focuses on the primary experience of the author and the author’s colleagues.