Khalim-authorised MAE loosening: coding window orientation exposes the known
SAP-10.2-vs-lodged offset the zeroed solar gains were masking; within-0.5 is
the north-star metric and jumps 20.0% -> 23.9%.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Manually verified in pashub (Khalim, 2026-07-14): deal 499584755922
(9 Council Houses, CW5 8AP) is F33, not the stale D67 — our computed 34.0
was right within a point; deal 499617935574 (Brightholme, 14 North Road)
is the accredited E43, not the preliminary 53. 58 Hackle Street (D58) and
16 Bingley Close (E52) were confirmed correct, so our +7.8/+5.7 deviations
there are extraction bugs to hunt next. Harness MAE 1.684 -> 1.551; ceiling
ratcheted to 1.56.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The extractor now captures "Heating System (Other):" and the mapper resolves
it to the Table 4a code (301, community boilers) + Table 12 community fuel
(51 via the shared _resolve_community_heating_fuel_code), so
is_heat_network_main routes the DLF / standing-charge / 80%-efficiency
branch instead of pricing the dwelling as an ordinary mains-gas boiler
(fixture 507644414148: +14.3 over-rate closes by ~8.6). Harness MAE
1.726 -> 1.684; ceiling ratcheted to 1.70.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
_parse_room_in_roof captures the RdSAP §3.10 block (age range, floor area,
gables with Exposed/Party type, slopes, common walls, flat ceiling as
length x height) on main and extension roof spaces; both part builders now
carry it to sap_room_in_roof (issue #1590 bug 5 — closes the last #1590
subtask). Harness MAE 1.748 (754917 corrects to pashub's own pre-SAP; RIR
surfaces now billed per-surface instead of as insulated loft).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The surveyed "Ventilation type" label never reached
mechanical_ventilation_kind, so ventilation_from_cert silently defaulted every
mechanical system to NATURAL (24d), dropping its ACH heat loss — 76/205
cohort fixtures lodge dMEV/MEV/PIV (issue #1590 bug 4). Mapping mirrors the
gov-API _API_MECHANICAL_VENTILATION_TO_KIND table (PIV-from-loft is
"as natural"). Harness: within-0.5 12.2% -> 18.5%, MAE 2.538 -> 1.730 — the
campaign's largest single move; floors ratcheted to 0.18 / 1.75.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
"Not connected to electricity meter" -> 1 (zero Appendix M credit), "Connected
to dwellings electricity meter" -> 2; the raw string fell through the credit
gate's non-int branch to True, crediting a separately-metered array (issue
#1590 bug 3, fixture 499516101839 -6.9 SAP). Harness MAE 2.571 -> 2.538;
ceiling ratcheted to 2.55.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
"Photovoltaic array kWp Known? Yes" lodges a per-system block (kWp, pitch,
orientation, overshading) instead of the percent-roof estimate; the extractor
only read the estimate, so measured PV never reached the mapper and the
Appendix M credit was silently zero (issue #1590 bug 1). Harness MAE
2.632 -> 2.571 (fixture 507639151843's 13.5-SAP under-rate closes to +0.5);
ceiling ratcheted to 2.58.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
"Insulation At: None" is the assessor recording zero loft insulation, not an
unknown — with thickness left None, u_roof fell through to the age-band
"assumed insulated" default (0.16 W/m²K at band J/K) instead of the Table 16
uninsulated row (2.30), understating roof loss ~14x (issue #1590 bug 2).
Harness MAE 2.701 -> 2.632 (the two ~7-SAP roof over-raters correct exactly);
ceiling ratcheted to 2.64.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two hubspot_deal_data corrections: 499539910905 D58->B82 (confirmed bad row)
and one C73->C75. Rebuilt via scripts/build_pashub_accuracy_fixtures.py
(no --force; PDFs unchanged).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Secondary fuel 'Mains gas'/'Mains Gas'->26 and 'House Coal'->11 (Table 32);
main-heating control resolution becomes group-aware with a Table 4e Group 3
map ('Charging system linked to use of community heating, room thermostat
only' -> 2306, the code the accredited Elmhurst certs lodge for this cohort;
all four linked-to-use codes are calculation-identical). All 205 Guinness
fixtures now compute (was 201/4 xfails); ratchet re-baselined to the
full-coverage aggregate (12.2% within-0.5 floor, MAE ceiling 2.71) with the
two newly-computable outliers documented for verification.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The control gap surfaces as UnmappedSapCode on main and as UnmappedPasHubLabel
once the #1557 control mapper lands (unmapped community-heating control), so the
harness must swallow both; only the closed fuel-specific MissingMainFuelType is
dropped as a fuel-drop tripwire.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Foundation for PRD #1555: runs each PAS Hub site-note PDF through the
extractor -> EpcPropertyData -> Sap10Calculator and gauges the computed
SAP against pashub's own SAP-10.2 `pre_sap` (from hubspot_deal_data).
- test_pashub_sap_accuracy.py: hybrid gate. Per-fixture "must compute"
(xfail on the known in-progress mapper gaps MissingMainFuelType /
UnmappedSapCode / UnmappedPasHubLabel) + aggregate within-0.5 ratchet
floor, mirroring test_sap_accuracy_corpus.py.
- 205 image-stripped site-note PDFs + manifest.json. Images stripped so
the repo footprint stays ~52MB while the text layer the extractor reads
is byte-identical.
- build_pashub_accuracy_fixtures.py: provenance/rebuild from S3 +
hubspot_deal_data.
All 206 currently xfail on the known heating-string mapper gaps; each fix
(#1556-1568) flips its fixtures to computing and ratchets the floor.
Refs #1555#1568
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Thread the UPRN the PashubService has already resolved for a job into the
PasHub site-notes mapper so the EpcPropertyData aggregate is born with its
uprn set, and the existing save_epc_property_data path persists it.
- EpcPropertyDataMapper.from_site_notes gains uprn: Optional[int] = None and
sets it unconditionally (site notes never carry a UPRN natively).
- parse_site_notes_pdf / _parse_pashub forward the uprn; the Elmhurst branch
is untouched.
- PashubService coerces uprn str -> int in one place, carries it on the
internal upload record, and passes it into parse_site_notes_pdf.
- No new lookups; jobs with no known UPRN still persist null, unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the mapper-driven e2e cascade pin for "simulated case 50" (000565 semi,
electric storage main SAP 402 + portable electric secondary + MVHR + whc-903
DUAL electric immersion + 160 L cylinder, Economy-7). Routes the Summary PDF
through extractor + mapper + calculator like the other 000565 fixtures.
Locks in two off-peak fixes this case ground-truthed:
- the Table 13 HW high/low split applied to CO2/PE (commit 39ae2cf0), and
- the Table 12a Grid 2 MVHR fan fraction 0.71/0.58 (commit cd5113ab).
All 11 SAP-result fields reconcile to the U985 worksheet EXACTLY, including
the (272) rating CO2 2397.1237 — SAP 38.8426 (=39), cost £1317.0116, water
1668.0788 kWh, fans 315.6384 kWh.
Summary mirrored to the tracked fixtures dir so the test doesn't depend on
the unstaged `sap worksheets/` workspace.
pyright strict gate not run locally (pyright not installed in this container).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adds the mapper-driven e2e cascade pin for "simulated case 52" (000565
semi + regular non-combi mains-gas boiler SAP 102 + 160 L foam cylinder
heated from the main, no cylinder stat, uninsulated primary pipework,
standard tariff). Routes the Summary PDF through extractor + mapper +
calculator like the other 000565 / 001431_case* fixtures.
This closes the last untested branch of the cylinder/water chain: the
SAP 10.2 §4 cylinder storage loss (Table 2/2a/2b lines 51-55) + the
Table 3 PRIMARY circuit loss (59, uninsulated pipework + no stat) that
combi/immersion fixtures don't reach. All 11 SAP-result fields reconcile
to the U985 worksheet EXACTLY with no calculator change — SAP 57.2904
(=57), cost £911.1973, water 3929.7635 kWh — confirming the cylinder-loss
derivation is correct.
Summary mirrored to the tracked fixtures dir so the test doesn't depend
on the unstaged `sap worksheets/` workspace.
pyright strict gate not run locally (pyright not installed in this container).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The SAP/EI rating is computed on UK-average weather (Appendix U Tables
U1-U3 region 0) so ratings are nationally comparable, but Appendix U
paragraph 1 (PDF p.124) requires that "other calculations (such as for
energy use and costs on EPCs) are done using local weather. Weather data
for each postcode district are taken from the PCDB". `Sap10Calculator.
calculate` ran ONE cascade (UK-average) and fed it to SAP, CO2 AND primary
energy, so every cert's EPC-displayed CO2/PE were computed on the wrong
climate. Because most of England is warmer than the UK-average, this
systematically OVER-counted heating demand on the emissions/PE outputs.
The two cascades (`cert_to_inputs` rating, `cert_to_demand_inputs`
postcode) already existed; this wires the demand cascade into the
production entry point and grafts its CO2/PE onto the rating result (SAP
unchanged). The corpus gauge's longstanding +5% CO2/PE over-estimate was
mostly this climate bug, NOT (as previously diagnosed) per-cert mapper
fidelity:
CO2 MAE 0.26 -> 0.12 t/yr (bias +0.18 -> +0.04)
PE MAE 13.6 -> 3.8 kWh/m2 (bias +9.0 -> +0.24)
SAP within-0.5 = 69.7% (rating cascade, unchanged)
Worksheet-validated to 1e-4 on simulated case 45 (heat-pump ground-floor
flat, postcode W6): the P960 prints the current dwelling twice — Block 1
on UK-average weather (SAP 60.5318, CO2 692.13) and Block 2 on postcode
weather (CO2 626.78, PE 6581.59). Both reproduce exactly. Added a tracked
case-45 Summary fixture + two-cascade cascade pin as a permanent guard,
and ratcheted the corpus CO2/PE ceilings to 0.13 / 4.2. The e2e Elmhurst
suite (Block-1 line refs) now pins the rating cascade directly; the two
Vaillant overlay snapshots refreshed to demand-cascade CO2/PE.
pyright not installed in this codespace (strict gate not run locally);
change is type-trivial (dataclasses.replace over SapResult).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
SAP 10.2 §2 (17)-(18): a measured/design air permeability at 50 Pa from a
Blower Door test routes infiltration via `(18) = AP50/20 + (8)`, in
preference to the components-based (16) estimate. The Elmhurst extractor
read only the AP4 ("Pulse") column of §12.2, so a Blower Door result
(§12.2 "Pressure Test Result (AP50)") fell through to the structural-
infiltration default — over-counting ventilation heat loss.
Surfaced by simulated case 44 (AP50 4.50): effective air change rate was
0.81 vs the worksheet's 0.58 (+38% ventilation loss). The cascade already
supports `air_permeability_ap50` (preferred over AP4); this wires the read
end to end (extractor → ElmhurstSiteNotes → SapVentilation → cert_to_inputs).
Pinned against the case-44 P960 §2 at abs=1e-4: (18) infiltration 0.3417
(= 4.5/20 + 0.1167) and (25) Jan effective ach 0.5812. Worksheet harness
stays 47/47 0-raised.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Wire the non-separated conservatory into the §3 heat-transmission +
§1 dimensions cascade per RdSAP 10 §6.1 (PDF p.49) + Table 25 (p.51):
"The floor area and volume of a non-separated conservatory are added to
the total floor area and volume of the dwelling. Its roof area is taken
as its floor area divided by cos(20°), and wall area is taken as the
product of its exposed perimeter and its height. ... The conservatory
walls and roof are taken as fully glazed ... Glazed walls are taken as
windows, glazed roof as rooflight."
New `worksheet/conservatory.py` derives the geometry:
- height from the equivalent storey count (§6.1: 1 storey → ground-floor
room height; 1½ → ground + 0.25 + 0.5×first; etc.);
- glazed WALL → window (27) at Table 25 U (double 3.1 / single 4.8) with
the §3.2 curtain resistance (R=0.04) → U_eff 2.758;
- glazed ROOF → rooflight (27a) at Table 25 roof U (double 3.4 / single
5.3) + curtain → U_eff 2.993;
- FLOOR → (28a) via BS EN ISO 13370 as an uninsulated SOLID ground floor
with 300 mm walls (§5.12, spec p.43), exposed perimeter = glazed
perimeter → U 0.89;
- glazed wall + roof + floor areas join (31)/(36); the fully-glazed
structure walls/roof add nothing (the glazing IS the window/rooflight).
`dimensions_from_cert` adds the conservatory floor area to TFA (4) and
floor area × height to volume (5) (feeds ventilation (8)), without making
it a storey (avg storey height for §2 infiltration is unchanged).
Pinned against the simulated case-44 P960 §3 at abs=1e-4 — every line ref
EXACT: (4) 95.3800, (5) 257.1630, (27) 96.1169, (27a) 38.2201, (28a)
21.4164, (29a) 35.5852, (30) 7.4688, (31) 294.2900, (33) 207.3274,
(36) 23.5432. The remaining whole-dwelling SAP/CO2 gap is the §6 solar
gains, closed in the next slice. Worksheet harness stays 47/47 0-raised.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RdSAP 10 §6.1 (PDF p.49) models a non-separated (heated) conservatory as
part of the dwelling. Until now the Summary §5 block was reduced to an
inert `has_conservatory` bool and the geometry (floor area, glazed
perimeter, glazing, storey height) was dropped on both paths.
Plumbing only — no cascade consumer yet (Slices B/C/D wire §3/§6):
- ElmhurstSiteNotesExtractor reads the §5 Conservatory block into a new
`Conservatory` site-notes record (scoped to §5 so the generic
"Floor Area"/"Room Height" labels can't collide with §4 dimensions);
- domain gains a frozen `SapConservatory` (floor area, glazed perimeter,
double/single glazing, thermally-separated guard, equivalent storey
count) on `EpcPropertyData.sap_conservatory`;
- the Elmhurst mapper threads it through, dropping SEPARATED
conservatories per §6.2 ("A separated conservatory ... is disregarded").
Verified against the simulated case-44 Summary (RefNo 001431): extracts
floor_area=12.0, glazed_perimeter=9.0, double_glazed=True, 1 storey.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Golden regression fixture for the multi-feature dwelling that surfaced the
two Elmhurst-extractor bugs in a33707f8. case 43 is a 2-BP mid-terrace with
a DETAILED room-in-roof (two slopes, two flat ceilings, party + exposed
gables, two common walls), a MIXED-insulation multi-section roof (Main
insulated + Extension uninsulated 2.30), a DRY-LINED extension solid wall,
a mains-gas boiler (102 / control 2106) and a House-coal solid-fuel
secondary (633).
Routes the Summary PDF through the WHOLE extractor + mapper + calculator
pipeline (no hand-built EpcPropertyData) and pins the §3 fabric + SAP-rating
block at abs=1e-4: (29a) walls 74.5800, (30) roof 38.5008, (33) fabric
172.7844, continuous SAP 73.2332 = (258), CO2 3518.3037 = (272). Guards the
detailed-RR slope/common_wall surfaces, the dry-lining R=0.17 adjustment,
and the per-part mixed-roof billing together. Summary mirrored to
backend/documents_parser/tests/fixtures/Summary_001431_case43.pdf; provider
module mirrors the _case6/_case21 pattern, assertion in
test_section_cascade_pins. Harness 47/47; regression = the 3 pre-existing
fails; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two compensating Summary-extractor bugs surfaced by simulated case 43 (a
2-BP mid-terrace with a detailed room-in-roof + a dry-lined extension wall).
Their fabric errors nearly cancelled (walls net −0.76 W/K), hiding both
behind a deceptively small +0.05 SAP delta.
Bug 1 — main/extension wall dry-lining never read. The §7 "Dry-lining:
Yes/No" line was parsed only for ALTERNATIVE walls; the main/extension
WallDetails dropped it, so a dry-lined solid wall was billed at its
un-adjusted base U. RdSAP 10 §5.8 + Table 14: a dry-lined uninsulated wall
adds R=0.17 → U = 1/(1/U_base + 0.17). Case 43 Ext1: solid brick 1.70 →
1.32. Added `WallDetails.dry_lined`, read it in the extractor (both the
main-wall builder and the As-Main copy), threaded it to the domain
`wall_dry_lined` (emit None when undried — cascade-equivalent to False,
keeps the field absent for the non-dry-lined majority).
Bug 2 — the LAST room-in-roof surface row's U over-read. The per-row token
scan stops at the next RIR-row name; the final surface (no successor) over-
read into the following section, shifting the trailing-token slotting and
silently zeroing its `default_u` (case 43 Common Wall 2: 1.90 → 0.00 → the
2.4 m² common wall billed at U=0 instead of the main-wall 1.90). Stop the
scan at the row's natural end — the "Yes"/"No" u_value_known flag plus the
trailing u_value numeric.
Case 43 now reproduces the P960 EXACTLY: (29a) walls 74.5800, (33) fabric
172.7844, continuous SAP 73.2332 = (258), CO2 3518.30 = (272), all <1e-4
(was SAP +0.0455 / CO2 −8.04). Harness 47/47 0 raised; regression = the 3
pre-existing fails; pyright net-zero (51=51).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`u_roof` only implemented the joist column, so roofs lodged insulated at
rafters (`roof_insulation_location == 1`) were mis-billed at the joist U
on both the API and Summary paths — under-stating loss, over-rating SAP.
RdSAP 10 §5.11.2 Table 16 (spec p.42-43) gives a distinct "insulation at
rafters" column (2): the rafter cavity is shallower than a loft void, so
the same depth yields a higher U (200 mm: rafters 0.29 vs joists 0.21).
§5.11 Table 18 (p.45) likewise carries a rafters column (2) for unknown /
as-built thickness (footnote (1): "The value from the table applies for
unknown and as built") — band A-D = 2.30, E = 1.50, F = 0.68, diverging
from the joist column's 100 mm-equivalent 0.40 default (footnote (4)).
- add `_ROOF_RAFTERS_BY_THICKNESS` (Table 16 col 2) + `_ROOF_RAFTERS_BY_AGE`
(Table 18 col 2) to rdsap_uvalues; `u_roof` selects them via a new
`insulation_at_rafters` flag (ignored for flat / sloping-ceiling roofs).
- `heat_transmission` derives the flag PER BUILDING PART from
`roof_insulation_location` (gov-API int 1 / Summary "R Rafters"), which
also fixes the multi-part dedup-roof-join problem: each part's own
location now drives its U, replacing the unattributable joined
`epc.roofs[]` description.
Worksheet-validated to 1e-4: simulated case 41 (4-bp — Ext1 rafters 200mm
→ 0.29, Ext3 rafters As-Built band F → 0.68; roof total 24.8350) and case
42 (6 variants — rafters 50mm → 0.88, rafters unknown band C → 2.30,
joists/none unchanged). Case 40 stays exact (roof 35.340, total 441.1606);
worksheet harness 47/47.
Corpus within-0.5 66.9% → 66.5% (gates 0.65/1.08 hold) — a spec-correct
shift, NOT a regression: all 15 corpus rafter certs carry redacted (None)
thickness yet lodge roof EER 2-4 (insulated), so the open API blanked a
specified thickness and the spec's unknown-rafter 2.30 default correctly
over-states them. Recovery needs a roof-EER→thickness inference on the
API path (follow-up), not a change to the U-table.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Elmhurst Summary §15.1 lodges "Cylinder Size: Value known" with the
measured volume in the "Cylinder Volume (l)" line — the Summary-path
equivalent of the gov-API "Exact" descriptor. The mapper had no entry for
"Value known" so `_elmhurst_cylinder_size_code` raised UnmappedElmhurstLabel,
and even once mapped the measured volume was never threaded through, so the
cascade dropped the cylinder storage loss (~468 kWh/yr) from (219) water
heating on every measured-volume-cylinder Summary.
Per RdSAP 10 §10.5 Table 28 (p.55) a measured cylinder volume is used
directly. Map "Value known" → cascade code 6 (Exact) and thread the §15.1
"Cylinder Volume (l)" value into SapHeating.cylinder_volume_measured_l, which
`_cylinder_volume_l_from_code` (cert_to_inputs.py:5281) already reads for
code 6 — mirroring the gov-API path (mapper.py:1575/1885).
Pins simulated case 39 (P960-0001-001431): an age-A mid-terrace on direct-
acting electric room heaters (SAP code 691, cat 10, control 2602) with
electric-immersion DHW off a 117 L "Value known" cylinder. The full
extractor→mapper→calculator cascade now reproduces the worksheet's SAP-rating
block EXACTLY — SAP value 36.6365 (band F) and (272) CO2 2056.0731 kg/yr,
with (219) water heating 2637.5049 and (255) total energy cost 1802.0039.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The realistic re-generation of case 37 (code-117 gas boiler, control 2102,
+ a MAINS-GAS condensing gas-fire secondary code 611, vs case 37's biogas
605). The full extractor -> mapper -> calculator pipeline reproduces the
worksheet's SAP-rating block EXACTLY: continuous SAP 60.9152 (Δ 2e-5) and
(272) CO2 5801.0770 (Δ ~0). This confirms the boiler-efficiency /
control-2102 −5pp interlock / secondary-fuel handling are all correct, and
that case 37's +7 gap was purely the biogas sub-fuel the Summary export
cannot carry.
Summary mirrored into backend/documents_parser/tests/fixtures so the pin
runs without the unstaged workspace. PE not pinned — it is a separate
DPER block (different scope) already guarded by the corpus PE gauge.
Worksheet harness 47/47 unchanged; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The §11 layout parser keys a window's wall Location on the glazing-prefix /
orientation tokens around its data row. An alt-wall window lodges its
"Alternative wall 1" Location wrapped across the lines bracketing the W×H×A
row. For a DOUBLE-glazed alt window the prefix line also carries the glazing
phrase ("Double between 2002 Alternative wall"), so the partition breaks
there and the location survives into the window's pre-data slice. For a
SINGLE-glazed alt window the "Alternative wall" line stands alone with no
glazing-type word, so _partition_after_manuf scanned past it and swallowed
it into the PREVIOUS window's suffix — the window then defaulted to
"External wall" and its opening deducted from the wrong wall.
Fix: treat a standalone wall-location line ("Alternative wall" / "External
wall" / "Party wall") as a window boundary in _partition_after_manuf, so it
attaches to the following window's prefix. Surfaced by simulated case 34
(cert 001431 electric-storage flat): 2 of 4 single-glazed alt-wall windows
were mis-allocated, splitting 2.75/10.78 m² instead of the worksheet's
4.63/8.90 corridor/external opening areas.
Elmhurst-extractor only; API gauge unaffected. Regression gate green (3
pre-existing fails unrelated); worksheet harness 47/47 unchanged. Case 34's
alt-wall opening area now matches the worksheet; the corridor wall net area
is correct (the cert's residual is now isolated to the unheated-corridor
door, a separate slice).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Elmhurst Summary §7 lodges "Alternative Wall N Sheltered Wall: Yes" for
a sub-area adjacent to an unheated buffer (e.g. a flat's corridor wall),
but the extractor dropped it and _map_elmhurst_alternative_wall never set
SapAlternativeWall.is_sheltered — so the cascade billed the sub-area at its
full exposed U instead of the RdSAP 10 Table 4 (p.22) sheltered U =
1/(1/U + 0.5).
The calculator already applies is_sheltered (_alt_wall_w_per_k) and the
gov-API path already wires sheltered_wall=="Y"; this brings the Elmhurst
front-end to parity. Three-part change: AlternativeWall.sheltered field +
_alternative_walls_from_lines parse ("Alternative Wall N Sheltered Wall") +
_map_elmhurst_alternative_wall is_sheltered=a.sheltered.
Surfaced by simulated case 34 (cert 001431 electric-storage flat): the
6.02 m² corridor wall billed at full U=1.50 (9.03 W/K) instead of the
sheltered 0.86 (5.18 W/K) — +3.85 W/K, -1.61 SAP. Post-fix the alt wall
matches the worksheet's (29a) 5.177 and case 34 closes from -1.61 to -0.30
(remaining residual is a separate window/wall area-allocation thread).
Elmhurst-mapper only: API SAP gauge unchanged (57.6% within 0.5); worksheet
harness 47/47 unaffected; regression gate green (3 pre-existing fails
unrelated); pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
