Model/domain
Khalim Conn-Kowlessar ba56647401 fix(heat-network): derive dwelling age band from first non-empty building part
The GOV.UK API lodges a junk empty leading building part (all fields
None) ahead of the real Main Dwelling on some certs. Four sites in
cert_to_inputs.py read `sap_building_parts[0].construction_age_band` →
got None → silently dropped the dwelling age band. New `_dwelling_age_band`
helper takes the first part that lodges a band (a no-op for normal certs
where [0] is the Main part).

Closes two age-band-keyed defects on the 5 affected certs:

- SAP 10.2 Table 12c (p.193): the heat-network Distribution Loss Factor
  defaulted to the K-or-newer 1.50 instead of the dwelling's true band
  (cert 8536-0929-6500-0815-7206 is age A → 1.20), inflating distribution
  loss by 30%.
- RdSAP 10 §4.1 Table 5 (p.28): the empty band ("") fell through the
  age-band branches to the H–M habitable-rooms branch, defaulting in
  phantom extract fans. The true band A correctly yields 0 fans
  (bands A–E → 0).

Cert 8536: 31.76 → 41.12 vs lodged 39 (was −7.24, now +2.12). API eval
mean|err| 1.197 → 1.192, signed −0.229 → −0.218; headline within-0.5
holds at 56.8% (8536 lands at +2.1, a documented overshoot vs the
faithful case-31 worksheet — separate slice).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-10 18:43:17 +00:00
..
addresses standardist Address 2026-05-22 10:13:32 +00:00
data_transformation moved classifier data transformation to an easy one 2026-06-01 14:53:34 +00:00
epc Remove EPC and asset_list changes unrelated to SAL handler 2026-06-01 16:39:09 +00:00
fuel_rates feat(fuel-rates): FuelRates snapshot + repository foundation (ADR-0014) 2026-06-02 09:29:07 +00:00
geospatial feat(geospatial): GeospatialRepo — OS Open-UPRN coordinate lookup (#1131) 2026-06-01 16:28:48 +00:00
property feat(property): Property aggregate + PropertyRepository (#1132) 2026-06-01 16:28:48 +00:00
property_baseline feat(baseline): sap_code_to_fuel normalizes via the calculator's own helper 2026-06-05 18:59:25 +00:00
sap10_calculator fix(heat-network): derive dwelling age band from first non-empty building part 2026-06-10 18:43:17 +00:00
sap10_ml test(efficiency): lock solid-fuel room-heater space eff to Table 4a column (B) 2026-06-10 11:09:12 +00:00
tasks added postcode splitter rewrite to ddd 2026-05-19 16:35:09 +00:00
postcode.py get rid of comments 2026-05-20 13:21:11 +00:00