Model/domain/modelling
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
..
generators Fix HHRSH storage heaters priced at peak rate (engine 48 vs Elmhurst 71) 2026-07-02 11:24:03 +00:00
optimisation refactor(modelling): type measure_type fields as MeasureType 2026-06-08 20:13:31 +00:00
scoring Rename SapEnergySource.mains_gas to gas_connection_available 🟩 2026-07-01 10:59:21 +00:00
__init__.py feat(modelling): Overlay Applicator folds EpcSimulation onto EpcPropertyData 2026-06-02 22:13:51 +00:00
ashp_rates.json refactor(modelling): load ASHP rates from a committed costs file 2026-06-06 23:19:53 +00:00
considered_measures.py feat(modelling): drive measure scoping from the Scenario's exclusions 2026-06-16 15:26:25 +00:00
contingencies.py feat(modelling): cost data for secondary-heating-removal (ADR-0028) 2026-06-11 13:51:16 +00:00
heating_rates.json feat(modelling): composite per-dwelling boiler + tune-up costing (ADR-0027) 2026-06-10 19:41:06 +00:00
measure_type.py feat(modelling): secondary-heating-removal generator + MeasureType (ADR-0028) 2026-06-11 13:35:14 +00:00
plan.py refactor(modelling): type measure_type fields as MeasureType 2026-06-08 20:13:31 +00:00
portfolio_goal.py refactor(modelling): move PortfolioGoal to domain/modelling/ 2026-06-03 22:44:48 +00:00
product.py feat(modelling): persist recommendation.material_id from the catalogue 2026-06-04 08:26:58 +00:00
products.py feat(modelling): composite per-dwelling boiler + tune-up costing (ADR-0027) 2026-06-10 19:41:06 +00:00
recommendation.py refactor(modelling): type measure_type fields as MeasureType 2026-06-08 20:13:31 +00:00
scenario.py feat(modelling): drive measure scoping from the Scenario's exclusions 2026-06-16 15:26:25 +00:00
simulation.py Rename SapEnergySource.mains_gas to gas_connection_available 🟩 2026-07-01 10:59:21 +00:00
solar_potential.py Harden Dwelling-Roof Cap on real data: positional segments, ground-floor basis 🟩 2026-06-26 12:24:52 +00:00
solar_rates.json feat(modelling): Products.solar_bundle_cost + committed solar rate sheet 2026-06-08 12:10:27 +00:00
valuation.py feat(modelling): ValuationUplift domain class (percentage-primary) 2026-06-04 08:33:19 +00:00