5 certs in a 2026 API sample raised `KeyError: 'rr_common_wall_area_m2'`
and were blocked from computing. Root cause: `_part_geometry`'s early
return (taken when a building part lodges no sap_floor_dimensions —
e.g. a party-wall-only or RR-only extension as bp[0]) returned only 6 of
the 9 keys the full return exposes, omitting rr_common_wall_area_m2,
rr_gable_area_m2 and cantilever_floor_area_m2. The §3.9 RR contribution
block reads geom["rr_common_wall_area_m2"] / ["rr_gable_area_m2"] for
EVERY part, so the floorless part's truncated dict raised KeyError at
heat_transmission.py:974.
Fix: the early return now exposes all 9 keys, the three RR/cantilever
geometry values defaulting to 0.0 — correct, since a part with no floor
dimensions has no derivable RR shell or cantilever (no floor area).
Pure contract-completion bug; no spec/U-value change.
Regression test pins the invariant directly: a floorless part's
_part_geometry keys must equal a with-floors part's keys. Validated: all
5 certs now compute (4 within ~2 SAP of lodged; the 5th, 8536, has a
separate residual). §4 suite 2393 passed; heat_transmission.py pyright
unchanged at 12, test file at 71.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
above) → None
The 2026 sample lodges roof_construction=6 (1 cert, "Thatched, with
additional insulation") and =7 (6 certs, "(same dwelling above)" /
"(another dwelling above)"), both raising UnmappedApiCode and blocking
the cert. roof_construction_type is read ONLY for the §3 "sloping
ceiling" cos(30°) inclined-surface factor (Slice 89); the base roof
U-value comes from the global roofs[].description. Neither code is a
sloping ceiling:
- 6 = thatched — U set by the description, not this field;
- 7 = same/another dwelling above — an internal ceiling with no roof
heat loss (the roof-side analogue of floor_construction code 0,
governed by the roof_heat_loss / description path).
Map both to None: carries no information the cascade consumes here and
correctly avoids the cos(30°) false-trigger. Empirically inert and
validated — roof W/K is byte-identical whether 6/7 map to None or to an
explicit pitched string across all code-6/7 certs in the sample. 5 of
the 7 now compute (e.g. thatched cert 2276 SAP 62.8 vs lodged 63); the
other 2 also carry a gable_wall_type 2/3 raise (separate, worksheet-
backed slice).
Dict value type widened to Optional[str]. §4 suite 2392 passed; mapper.py
pyright unchanged at 32; new tests suppress reportPrivateUsage (net-zero).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A 2026-register cert (4519-9056-4002-0222-4802) omits the top-level
post_town entirely (its town sits only in address_line_3 "BARNSTAPLE").
RdSapSchema21_0_x declares post_town as a required no-default field, so
from_dict raised "missing required field 'post_town'" and blocked the
whole cert from computing.
post_town is address metadata the SAP cascade never reads (no consumer
in domain/sap10_calculator/), so default an absent post_town to "" in a
from_api_response pre-processor (mirroring _normalize_shower_outlets) —
inert for the calculation, keeps the cert mappable. The schema dataclass
can't simply give post_town a default: it is a plain (non-kw_only)
dataclass with 57 required fields after post_town, so a mid-list default
would break field ordering.
Validated: cert 4519 now maps (post_town="") and computes SAP cont 74.68
vs lodged 75. §4 suite 2392 passed; mapper.py pyright unchanged at 32;
new tests suppress reportPrivateUsage (net-zero).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The 2026 sample's second-largest mapper raise: 37 certs lodge
sap_floor_dimensions.floor_construction=0, which raised UnmappedApiCode
and blocked the cert. Code 0 is the "not recorded / not applicable"
sentinel — 33/37 pair it with floor_heat_loss=6 ("another dwelling
below", an upper-floor flat with no ground floor to describe); the rest
carry mixed Solid / unheated-space descriptions. There is no single
construction to assert.
Map code 0 → None, which defers to RdSAP 10 Table 19 ("where floor
construction is unknown" → age-band default) — identical to how an
unlodged floor_construction (the 993 None certs) is already handled, and
honest about the absence (cf. the no-misleading-insulation_type rule).
Empirically inert and validated: across all 37 code-0 certs the cascade
floor W/K is byte-identical whether code 0 maps to None or to an explicit
"Solid" string — the another-dwelling-below floors compute to 0.0 W/K
(handled via floor_heat_loss + property_type=Flat + floors[].description,
per the _API_FLOOR_HEAT_LOSS_TO_FLOOR_TYPE code-6 note), and the few
genuine ground/unheated floors hit the same age-band default either way.
All 37 now compute (were raising).
Dict value type widened to Optional[str] for the None entry; helper
already returns Optional[str]. §4 suite + schema-mapper tests green
(pre-existing test_total_floor_area failure unrelated); mapper.py pyright
unchanged at 32; new test suppresses reportPrivateUsage (net-zero).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A random 1000-cert Jan–May 2026 EPB-register sample surfaced 53 certs
lodging sap_floor_dimensions.floor_construction=3, which raised
UnmappedApiCode and blocked the whole cert from computing (~44 of the
sample's mapper raises). RdSAP 10 field 3-1 "Floor construction"
enumerates the lowest-floor construction as solid / suspended timber /
suspended, not timber, and the spec's "Suspended not timber (structural
infiltration 0)" makes the split load-bearing.
Map code 3 to the canonical "Suspended, not timber" string (the same
value the site-notes mapper already emits — cross-mapper parity):
- u_floor takes the suspended BS EN ISO 13370 branch via the
"Suspended" prefix (_floor_is_suspended_from_description), and
- _has_suspended_timber_floor_per_spec's exact-match
`!= "Suspended timber"` gate correctly does NOT fire, so the §5 (12)
0.1/0.2 floor-infiltration adjustment is skipped (structural
infiltration 0) — exactly the spec rule for not-timber suspended.
Validated: all 5 sampled code-3 certs now compute (e.g.
0340-2877-5570-2606-5965 floor_construction_type="Suspended, not
timber", SAP cont 60.12 vs lodged 60). Confirmed against the cert's own
global floor descriptions ("Suspended, …", floor_heat_loss=7).
Code semantics established from the RdSAP 10 spec + the lodged certs'
human-readable floor descriptions (the EPB /api/codes endpoint carries
no floor_construction enum). §4 suite + schema-mapper tests green
(the pre-existing test_total_floor_area failure is unrelated). mapper.py
pyright unchanged at 32; new test suppresses reportPrivateUsage to keep
net-zero new errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Record S0380.218 shipped, bump HEAD/next-slice, note both certs are
0-residual cross-validated golden fixtures and flag the optional
Summary-path regression guard as the cheap follow-up.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two certs fetched fresh from the GOV.UK EPB register, each with an
Elmhurst Summary PDF (input) and a dr87 worksheet PDF (the (1)..(286)
ground truth):
0340-2467-9260-2006-6521 (Summary_000922 / dr87-0001-000922)
5500-5070-0822-0201-3663 (Summary_000920 / dr87-0001-000920)
Both run through BOTH front-ends — from_api_response and
from_elmhurst_site_notes — and through the rating + demand cascades.
Cross-mapper parity holds: the two paths agree to <1e-4 on continuous
SAP, fuel cost, CO2 and PE. Both paths reproduce the worksheet exactly:
0340: (255) cost 776.4295, (272) CO2 2875.0498, (286) PE 16474.5616;
fabric (33) 171.6188, (37) 205.9358; SAP int 70 = lodged.
5500: (255) cost 751.8295, (272) CO2 2423.4547, (286) PE 14397.0118;
fabric (33) 141.1226, (37) 167.3696; SAP int 66 = lodged.
Pinned in two tables of test_golden_fixtures.py:
- _EXPECTATIONS / test_golden_cert_residual_matches_pin — SAP/PE/CO2
residual vs the integer-rounded lodged register (SAP resid +0 both).
- _WORKSHEET_PE_CO2 / test_golden_cert_pe_co2_matches_worksheet —
PE (286)/(4) and CO2 (272) vs the worksheet at +0.0000 (the
load-bearing 1e-4 check; lodged register is integer-rounded).
Dropped-field audit (raw JSON keys vs the schema-21.0.1 dataclass
fields consumed by from_dict) re-run on both fresh JSONs: no new
silently-dropped fields — only created_at metadata and the
shower_outlet_type/shower_wwhrs keys already handled by
_normalize_shower_outlets (mapper.py:2047). No calculator or mapper
change required; this is pure validation + regression-pinning.
Full §4 suite: 2392 passed, 1 skipped.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Next-agent brief: fetch certs fresh from the EPC API (two new API+Summary+
worksheet triples for cross-mapper parity, plus six dashboard-flagged certs).
Flags the critical reconciliation: the user's flagged numbers don't match the
golden-fixtures cascade (0390-2954-3640 pinned +0 but flagged -6.85; 7536/2130
flags are pre-this-session), so fresh-raw-JSON-vs-curated-fixture or a
different engine must be reconciled before debugging. Documents the EPC API
fetch mechanism, the dropped-field audit method, this session's 4 fixes, and
the conventions.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Second silently-dropped field from the 2130 audit: the schema-21
SapBuildingPart never declared `wall_insulation_thermal_conductivity`, so
`from_dict` discarded it. Captured it through schema 21.0.0/21.0.1 → domain
SapBuildingPart → API mapper, and wired it into u_wall's RdSAP 10 §5.8
documentary-evidence R-value calc (both the solid-brick §5.7/§5.8 path and
the cavity-composite path), replacing the bare 0.04 λ constant with a
resolved λ.
Resolver: absent / "Unknown" → the §5.8 default 0.04 W/m·K (mineral wool /
EPS); a mapped code → its λ; an unmapped integer code RAISES so the enum is
confirmed against a worksheet rather than silently mis-factored (same
incremental-coverage discipline as the glazing-type map). Only code 1
(= the default 0.04) is mapped — the sole observed value (cert 2130 Ext1).
Zero cascade effect today: the λ path fires only for solid-brick/cavity
walls with a *measured* wall thickness, and 2130 Ext1 lodges no wall
thickness, so its conductivity is captured-but-unused; all existing §5.8
certs lodge no conductivity → 0.04 default unchanged. The point is to stop
dropping lodged data and make λ correct when a future cert exercises it.
Suite: 2523 passed (1 pre-existing TFA fail); sap10_ml 237 passed (2
pre-existing stone-formula fails). Zero new pyright errors (46=46).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Updated 2130's pin notes with the case-18 finding: our cascade reproduces
the worksheet PV split to the decimal (gen 2684.17 / onsite 970.77 / export
1713.40), so the Appendix M1 β-split is exact, not the suspected bug. With
the gas PE factor also exact (1.13) and the wall measurement now wired
(S0380.215), 2130's +2/-11.72 is the irreducible API-only lodged residual
(0240-like), not a closable calculator bug. Notes-only; pin unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
pdftotext dumps of hand-entered Elmhurst worksheets wrap the §11 glazing-
GAP column ("16 mm or more") onto the glazing-TYPE token, yielding labels
like "Double between 2002 and 2021 16 mm or [1st]" that
`_elmhurst_glazing_type_code` didn't recognise → UnmappedElmhurstLabel,
blocking the whole Summary from parsing.
Added a fallback: when the lightly-cleaned label isn't a known key, strip a
trailing wrapped gap descriptor (`\s+\d+\s*mm\b.*$`) and retry. Applied
AFTER the direct lookup so explicitly-mapped interleaved variants (e.g.
"Double with unknown 16 mm or install date more", where the gap splits into
the middle) are unaffected. The gap drives the API-path U-value lookup, not
the site-notes glazing-type enum, so dropping it is loss-free for the
cascade.
Unblocks running our cascade on hand-entered worksheet Summaries — used to
validate the PV β-split against simulated case 18 (our split matches the
P960 worksheet exactly: gen 2684.17, onsite 970.77, export 1713.40).
Suite: 2391 passed, 1 skipped. Zero new pyright errors (mapper 32=32).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
