Grill-with-docs outcome for the glazing generator. Single planning-picked
Measure (double when unrestricted, secondary for conservation/listed/heritage),
upgrading all single-glazed windows together. The overlay writes lodged U-value
+ solar-g directly into WindowTransmissionDetails (our calculator consumes those
as inputs — it does NOT derive them from glazing_type, unlike Elmhurst) plus
glazing_type for the §5 daylight factor; EpcSimulation gains a per-window
`windows` surface. Priced flat average-per-window × single-glazed count.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
