Top-floor flat, solid brick uninsulated, uninsulated flat roof, gas combi,
SINGLE glazing (glazed_type 5). Built in accredited Elmhurst RdSAP10 and every
heat-loss element matches the engine EXACTLY: walls 53.18, flat roof 145.57,
floor 0, party 0, and — with the faithful single glazing — windows 34.7114 W/K
(8.62 m2 x eff U 4.0268). Confirms the mapper's glazed_type 5 -> single (raw U
4.8) is spec-correct per epc_codes.csv, not the double it superficially
resembles. Engine 61 vs lodged 62; the -1.18 is a cost-side residual, not a
fabric bug. Pinned to the observed engine 61.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
