Published in Interface, the technical journal of IIBEC, March 2026

Read what the author, Jason Wilen, has to say about this topic.

Achieving long-term performance in low-slope roof systems requires balance. Not balance between competing preferences, but balance across the full set of technical, environmental, and code-driven variables that define how a roof system performs over time. As this article highlights, challenges arise when designers, policymakers, or project teams prioritize a single attribute, such as reflectivity, first cost, or insulation levels, without fully accounting for the interdependencies within the roof assembly.

The Coalition for Sustainable Roofing (COSUR) advances a similar principle through its focus on holistic roof system design and sustainable roofing assemblies. Roofs are not individual products or isolated decisions. They are integrated systems that must simultaneously address durability, energy performance, moisture management, structural requirements, constructability, and long-term service life. When any one variable is elevated above the others, unintended consequences often follow, including reduced performance, shortened service life, or conflicts between building and energy code requirements.

This article reinforces the need to move beyond prescriptive, single-attribute approaches and toward performance-based strategies that recognize the complexity of roof systems. A balanced approach, grounded in science and field performance, enables designers and policymakers to achieve resilient, sustainable outcomes that align with the long-term interests of building owners and the broader built environment.