Jun-te Kim f5fbeb8e7e Fix HHRSH storage heaters priced at peak rate (engine 48 vs Elmhurst 71) ... The high-heat-retention storage-heater (HHRSH) recommendation was computed as LOWERING SAP and wrongly rejected by the Optimiser, leaving electric- room-heater flats/maisonettes stuck at band E with no sensible plan. Root cause: `_HHR_STORAGE_OVERLAY` sets `sap_main_heating_code=409` (HHR storage) + `meter_type="Dual"` but left `main_heating_category` at the pre-existing value (10 = electric room heaters). The SAP 10.2 Table 12a space-heating high-rate-fraction resolver classifies by category, so it misread the off-peak storage heating as direct-acting electric (1.00 high-rate) and priced 100% at the 7-hour peak rate (15.29p) instead of the storage off-peak split (0.00, ~5.5p). Verified against accredited Elmhurst RdSAP-10 on UPRN 100020942571 (8 Booth Close, SE28 8BW): engine HHRSH SAP 48 (peak-priced, cost £1087) vs Elmhurst 71 (cost ~£611); with the fix the engine gives 73 / £576. Two-part fix (defence in depth, so no future overlay/mapper can reintroduce it): - `_HHR_STORAGE_OVERLAY` now sets `main_heating_category=7`, keeping the overlaid EPC internally consistent. - `_table_12a_system_for_main` now classifies electric storage heaters by their Table 4a SAP code (401-409) as well as `category==7`, checked before the room-heater branch, so a specific storage code is authoritative over a stale/inconsistent category. Tests: new regression `test_storage_heater_classified_by_sap_code_over_stale_category`; updated the HHRSH overlay pin. Full accuracy corpus still passes (no regressions). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>		2026-07-02 11:24:03 +00:00
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__init__.py	refactor: lift-and-shift packages/domain/src/domain/sap → domain/sap10_calculator	2026-05-26 12:22:37 +00:00
cert_to_inputs.py	Fix HHRSH storage heaters priced at peak rate (engine 48 vs Elmhurst 71)	2026-07-02 11:24:03 +00:00