Clarify opaque wall and roof U-factor requirements in envelope analyst

[samuelduchesne]

Summary

Updated the envelope analyst agent guidance to provide more precise and actionable direction on building envelope U-factor requirements, moving away from oversimplified ranges toward proper reference to ASHRAE 90.1 prescriptive tables.

Key Changes

• Opaque walls: Replaced single undifferentiated U-factor range with clarification that prescriptive targets vary by both climate zone AND assembly type (mass, steel-framed, wood-framed, metal-building). Added explicit instruction to reference ASHRAE 90.1 Tables 5.5-1 through 5.5-8 rather than relying on a single range.
• Roofs: Expanded guidance to note that the 0.027–0.063 W/m²·K range applies specifically to insulation-above-deck assemblies, and that other roof types have distinct requirements in the same ASHRAE 90.1 tables.

Implementation Details

These changes improve the agent's ability to provide compliant recommendations by directing it to the correct prescriptive tables rather than encouraging reliance on approximate ranges that may not apply to the specific assembly type and climate zone under analysis.

https://claude.ai/code/session_01N3KLKaWtVxjoNtzVGQ8jkQ