Model/tests
Khalim Conn-Kowlessar e03f08cdc8 S0380.189: thermal mass parameter per RdSAP 10 §5.16 Table 22, not hardcoded 250
The §7 mean-internal-temperature cascade hardcoded the thermal mass parameter
(TMP) to 250 kJ/m²K at all 5 call sites, ignoring construction. RdSAP 10
§5.16 Table 22 (PDF p.48) makes TMP construction-dependent:

  100 kJ/m²K — timber frame, cob, park home (regardless of internal
               insulation); OR masonry (stone/solid brick/cavity/system
               built) WITH internal insulation.
  250 kJ/m²K — masonry WITHOUT internal insulation.

A too-high TMP inflates the §7 time constant τ = Cm/(3.6·H) (e.g. 40 h vs
16 h), under-cuts the temperature reduction between heating periods, and
over-states mean internal temperature → over-states space heating.

`_thermal_mass_parameter_kj_per_m2_k(epc)` classifies the MAIN building's
wall via the RdSAP `wall_construction` codes (5/7/8 = timber/cob/park) and
`wall_insulation_type` codes (3/7 = internal); unknown/curtain fall back to
the masonry 250 (no regression on unlisted classes). 17-case parametrised
test covers every Table 22 branch.

Diagnosis (per-line walk vs the user-simulated 001431 worksheet, same
archetype as golden cert 6035): fabric (26-37), internal gains (73), climate
(96)m and HTC (39) all EXACT; the entire +8.78 PE / -1.76 SAP gap was §7 MIT
(92) +0.71 °C, traced to TMP 250 vs Table 22's 100 (solid brick WITH internal
insulation). Fix closes the simulated case to 1e-4 on PE and CO2.

Blast radius: only golden cert 6035 re-pins (solid brick + internal
insulation) — SAP resid -6 → -2, PE +46.42 → +19.16, CO2 +1.07 → +0.42. The
47 dr87 cohort, 6 U985 fixtures and 41-variant heating corpus are all
masonry-no-internal → TMP unchanged at 250, all still pass. 2290 pass
(+17 new), 0 fail; pyright net-zero.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-02 22:01:35 +00:00
..
applications refactor(ara): rename FirstRunPipeline → AraFirstRunPipeline (PR #1139 review) 2026-06-01 15:00:33 +00:00
domain S0380.189: thermal mass parameter per RdSAP 10 §5.16 Table 22, not hardcoded 250 2026-06-02 22:01:35 +00:00
infrastructure Remove EPC and asset_list changes unrelated to SAL handler 2026-06-01 16:39:09 +00:00
orchestration Merge branch 'main' of https://github.com/Hestia-Homes/Model into feature/per-cert-mapper-validation 2026-06-02 16:10:41 +00:00
repositories Merge branch 'main' of https://github.com/Hestia-Homes/Model into feature/per-cert-mapper-validation 2026-06-02 16:10:41 +00:00
utilities tests framework completed 2026-05-20 14:00:19 +00:00
__init__.py added postcode splitter rewrite to ddd 2026-05-19 16:35:09 +00:00
conftest.py tests framework completed 2026-05-20 14:00:19 +00:00
test_lambda_packaging.py more tests to ensure we don't deploy something that is brokern 2026-06-02 15:03:20 +00:00