Model/datatypes/epc
Khalim Conn-Kowlessar 1ce1a6974b docs: flag deferred HP-on-E7 Table 12a + Table 4f pumps_fans cascade gap
Cert 000565 reveals a coupling between two SAP 10.2 cascade gaps
that prevents an isolated fix to either:

1. `_space_heating_fuel_cost_gbp_per_kwh` applies the E7 low-rate
   override to any electric main on a Dual meter. Per Table 12a,
   heat pumps on E7 use a ~33% high / 67% low split (cert 000565
   empirically) — NOT 100% low. The current binary all-low/all-high
   biases space-heating cost £-1.1k / £+1.3k respectively.

2. `_PUMPS_FANS_KWH_BY_MAIN_CATEGORY[4] = 0` for HPs (Table 4f says
   the circulation pump is in the COP). But certs with MEV / flue
   fans / solar HW pumps have those components added on top — cert
   000565's worksheet pin = 127.5 MEV + 45 flue + 80 solar = 252.5
   kWh, none of which the cascade currently sums.

Probed a fix that derives `main_heating_category=4` from
`sap_main_heating_code in {211-227, 521-527}` (the Table 4a HP
rows) and exempts category=4 from the off-peak override. The
mapper change is architecturally correct but coupling to (1) +
(2) leaves residuals worse at HEAD than at the prior commit — so
both edits are reverted and the spec rationale is folded into
TODO docstrings on the two helpers:

- `_elmhurst_main_heating_category` (mapper) — flags the deferred
  HP SAP code route + the two cascade prerequisites
- `_space_heating_fuel_cost_gbp_per_kwh` (cascade) — flags the
  Table 12a high/low split as a future cascade slice

Cohort regression check: 192 pass + 10 expected 000565 fails —
identical baseline to S0380.59. Docs-only, pyright net-zero.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-28 23:08:37 +00:00
..
domain docs: flag deferred HP-on-E7 Table 12a + Table 4f pumps_fans cascade gap 2026-05-28 23:08:37 +00:00
loaders demo generated for use in address2uprn 2026-05-08 14:48:15 +00:00
schema Slice S0380.48: surface real-API pv_batteries[].battery_capacity (5 kWh) 2026-05-28 19:17:02 +00:00
search bolstering testing 2026-04-28 13:46:09 +00:00
surveys Slice S0380.58: Elmhurst per-extension Room(s) in Roof extraction + TFA fix 2026-05-28 22:58:43 +00:00
__init__.py testing out rebaselining 2026-02-12 22:25:03 +00:00
construction_age_band.py testing out rebaselining 2026-02-12 22:25:03 +00:00
efficiency.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
floor.py preparing partiy class 2026-02-05 08:54:27 +00:00
fuel.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
heating_controls.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
hotwater.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
main_heating.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
property_type_built_form.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
roof.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
walls.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
windows.py testing out rebaselining 2026-02-12 22:25:03 +00:00