Behaviour delivered by the band-multiplier dict in the prior slice; this pins
the band-2 ("More than typical") case against the inherited 20.0.0 coefficient.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The gov-EPC API `wall_construction` enum diverges from the calculator's
internal WALL_* code-space (confirmed by the description-vs-code audit across
the corpus): API 1-5 align (granite/sandstone/solid-brick/cavity/timber), but
API 6=basement, 8=system built, 9=cob — whereas the calc constants are
WALL_SYSTEM_BUILT=6, WALL_COB=7, WALL_PARK_HOME=8, WALL_CURTAIN=9. Codes 8 and
9 therefore fell OUT of u_wall's `known_types` and resolved only via the
`walls[].description` fallback, with two failure modes:
- System built (API 8): a cert lodging no description silently defaulted to
cavity (1.5) instead of the system-built U (RdSAP 10 Table 6, e.g. band E
as-built 1.7). Latent in the corpus (all 43 carry a description) but a
silent mis-bill waiting to happen.
- Cob (API 9): a LIVE bug — calc WALL_CURTAIN=9 (set by the Summary path's
"CW" mapping, paired with a curtain_wall_age) intercepts code 9 in the
`construction == WALL_CURTAIN` branch, billing the cob wall at the curtain
default 2.0 regardless of description.
Fix, split by where each can be disambiguated safely:
- System built: `u_wall` gains `_GOV_API_WALL_CODE_TO_TYPE = {8: WALL_
SYSTEM_BUILT}`, resolving code 8 directly (calc WALL_PARK_HOME=8 is never
dispatched, so no collision; gov 6=basement is left to the basement
machinery — cannot remap 8→6).
- Cob: translated at the API mapper (`_api_wall_construction_code`, 9 →
WALL_COB=7) where the source is unambiguously the gov enum — the gov API
has no curtain code, so an API 9 is always cob. Applied to main + alt
walls across the from_rdsap_schema_* builders. The Summary path's "CW"→9
curtain mapping is untouched.
Worksheet harness UNAFFECTED (47/47, 0 divergers — Summary path unchanged).
API gauge 65.1% -> 65.3% within-0.5 (mean|err| 1.075 -> 1.059): the n=1 cob
cert now computes cob instead of curtain. 3 AAA tests (u_wall system-built
without description; mapper cob 9->7; aligned/system/basement pass-through).
pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`_CYLINDER_SIZE_CODE_TO_LITRES` held only codes 2/3/4 (Normal/Medium/Large →
110/160/210 L); codes 5 (Inaccessible) and 6 (Exact) fell through to None,
so the Table-13 high-rate fraction AND the cylinder storage loss were skipped
for those certs (20 code-6 certs in the API sample).
Per RdSAP 10 Specification (10-06-2025) §10.5 Table 28 (PDF p.55):
- Code 6 "Exact": use the lodged measured volume. The gov API carries it in
`cylinder_size_measured` (e.g. 150 L) — now plumbed through the 21.0.0/21.0.1
schema → mapper → `SapHeating.cylinder_volume_measured_l`.
- Code 5 "Inaccessible": 210 L if off-peak electric dual immersion, 160 L from
a solid-fuel boiler, otherwise 110 L (n=0 in the current sample, but
spec-complete).
New `_cylinder_volume_l_from_code` centralises Table 28 resolution and replaces
the three raw-dict call sites (`_hot_water_cylinder_volume_l`, the cylinder
storage-loss path, and the PCDB performance check) so all three honour codes
5/6 identically. `_cylinder_inaccessible_volume_l` applies the code-5 context
rule via the existing immersion/off-peak-meter/solid-fuel-boiler detectors.
Worksheet harness UNAFFECTED (47/47, 0 divergers): the Summary path lodges
neither code 5/6 nor a measured volume. API gauge: within-0.5 64.4% -> 65.1%
(mean|err| 1.085 -> 1.075) — the 20 code-6 certs now size their cylinder from
the measured volume. 4 AAA tests (code 6 measured; code 5 solid-fuel/default/
off-peak-dual-immersion). pyright net-zero.
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>
The Elmhurst dwelling-type classifier keyed "Top-floor flat" on a "dwelling
below" floor lodgement. A single-storey flat exposed BOTH top (a real
external roof) AND bottom (floor over partially-heated space, no dwelling
below) therefore fell through to "Ground-floor flat" — which the cascade's
_dwelling_exposure maps to has_exposed_roof=False, dropping the external
roof entirely.
Surfaced by simulated case 34 (cert 001431 reconfigured as a slimline
electric-storage flat): the worksheet bills (30) External roof = 39.98 m²
x U=2.30 = 91.95 W/K — the dominant heat-loss element — but the cascade
dropped it, under-stating space-heating demand by 42% (6550 vs 11357
kWh/yr) and over-predicting SAP by +21.76 (57.07 vs worksheet 35.31).
Fix: an exposed (non-party) roof puts the flat on the top storey
regardless of what is below it. Classify as "Top-floor flat" whenever the
roof is exposed; the flat's exposed floor is recovered downstream by the
existing per-BP is_above_partially_heated_space / is_exposed_floor override
in heat_transmission (§3). Party-roof flats ("another dwelling above") are
unaffected and stay Ground-/Mid-floor.
This is an Elmhurst-mapper (dwelling_type) bug, NOT a calculator bug: the
calculator correctly trusts dwelling_type, and the gov-API path supplies
the position directly (cert 0036 — a genuine ground-floor flat whose API
data lodges a "Pitched, no access" roof construction under another dwelling
— stays party, 2.51 W/K). API SAP gauge unchanged (57.6% within 0.5);
worksheet harness 47/47 unaffected; case 34 roof now exact (residual -1.61
is a separate flat-corridor wall-U thread). Regression gate green (3
pre-existing fails unrelated).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
When a property lodges an Alternative Wall, pdftotext interleaves the §11
"Location" column ("Alternative wall 1") into the wrapped glazing-TYPE cell,
producing labels like "Double between 2002 Alternative wall and 2021 1
Alternative wall" (cert 001431 storage-heater variants, simulated case 34).
The existing greedy trailing-suffix strip (\s+Alternative wall.*$) truncates
at the FIRST "Alternative wall", losing "and 2021" and yielding the
unmatchable "Double between 2002". Added a fallback that removes EVERY
"<External|Alternative|Party> wall [n]" fragment and any stray 1-2 digit
location index from the raw label, then retries the lookup. Loss-free: no
glazing-type key contains a wall-location phrase or a bare 1-2 digit number
(install-date years are 4 digits).
Unblocks the Summary cascade for any property with an Alternative Wall;
Summary-path only (the API path receives structured glazing codes, so the
API gauge is unaffected). Regression gate green (1 pre-existing fail
unrelated).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Elmhurst Summary section 15.1 "Hot Water Cylinder" block lodges
"Immersion Heater: Dual" / "Single"; the extractor dropped it, so the
Summary path left immersion_heating_type = None while the API path already
captured it. Capturing it drives SAP Table 13's high-rate-fraction
DHW-cost split (RdSAP 10 section 10.5 p.54: 1 = dual, 2 = single) and
brings the two front-ends to parity.
Three-file change: WaterHeating.immersion_type field +
_extract_water_heating parse (scoped to the 15.1..15.2 slice) +
_elmhurst_immersion_type_code mapper (strict-raise on an unmapped label,
mirroring _elmhurst_cylinder_insulation_code).
Safe to land now that the preceding commit zeroes the high-rate fraction
for 18-/24-hour tariffs: the 20 solid-fuel corpus certs (solid fuel 4-11:
WHC 903 dual immersion, 18-hour meter, 110 L) carry a dual immersion, but
their 18-hour tariff bills 100% low-rate per Table 12a's 7-/10-hour scope
— so they stay EXACT instead of regressing to the 10-hour-column ~0.10.
7-/10-hour Summary immersion certs now correctly cost the Table 13
high-rate fraction instead of falling to the immersion=None 100%-low
default.
Regression gate green (3 pre-existing fails unrelated); API gauge
unchanged (Summary-path-only): 57.6% within 0.5, mean|err| 1.185.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
pdftotext can wrap the §11 building-part column onto the glazing-TYPE
token without an intervening glazing-gap descriptor, e.g. "Double between
2002 and 2021 1st" (the "1st" marks the 1st Extension). The existing
trailing-gap fallback only strips the fragment when preceded by "N mm";
the bare ordinal raised UnmappedElmhurstLabel.
New `_ELMHURST_GLAZING_LABEL_TRAILING_BP_RE` strips a trailing ordinal
("1st"/"2nd"/…) or "Main" and retries the lookup. No glazing-type key
ends in an ordinal or "Main", so it is loss-free. Surfaced by worksheet
`simulated case 33` (direct-acting electric boiler + immersion), which
previously could not be routed through the Summary cascade.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
ADR-0027 Reduced-Field Synthesis: certs with no per-window array now get total
glazing = 0.148 x TFA x band-multiplier (median + quartile multipliers fit from
the 1000 real 21.0.1 certs), split 4-way across N/E/S/W with width=area/4,
height=1.0; glazing_type routed through the verified 21.0.1 cascade. Also guard
optional PhotovoltaicSupply.none_or_no_details (a parse straggler). Corpus maps
983/1000, up from 974.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Required->optional defaults (kw_only + data-driven from corpus presence) so
993/1000 certs that omit sap_windows parse, and honest Union[str, DescriptionV1]
typing for description/dwelling_type which the corpus lodges as localised dicts
in ~half the certs. The never-run 20.0.0 mapper path now produces EpcPropertyData;
974/1000 corpus certs map (xpass), up from 7.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
An LPG-boiler dwelling on the Summary → from_elmhurst_site_notes path
mapped to main_fuel_type=26 (mains gas), making it indistinguishable
from a mains-gas boiler downstream — wrong Table 12/32 cost / CO2 / PE
(bottled LPG is ~10.30 p/kWh vs mains gas 3.48), and it defeats any
"non-gas → gas only with a mains-gas connection" gate (an LPG dwelling
looks already-gas).
Root cause: the recommendation worksheets lodge the boiler carrier as
§15.0 "Water Heating Fuel Type: Bottled gas" (§14.0 carries only SAP
code 115, a Table 4b gas-family row, + "Main gas: Yes" in §14.2 — a
mains-gas CONNECTION, not the heating fuel). "Bottled gas" was absent
from `_ELMHURST_MAIN_FUEL_TO_SAP10`, so the §15.0 fuel resolved to None
and `_elmhurst_gas_boiler_main_fuel` fell through priority-1 to the
mains-gas meter flag → 26.
Map "Bottled gas" → 3 (bottled LPG MAIN heating): code 3 routes via
`API_FUEL_TO_TABLE_32`/`API_FUEL_TO_TABLE_12` → Table-code 3 (10.30 /
9.46 p/kWh). NOT the legacy "LPG bottled": 5 entry — API code 5 =
anthracite, and `canonical_fuel_code` resolves the same-valued Table-32
code 5 to anthracite (3.64 p/kWh), so a 5 here mis-prices the dwelling
as cheap solid fuel (verified: a 5 mapping moved SAP the WRONG way,
42.33 → 45.11; code 3 moves it to -6.40 vs the worksheet's -6.6499).
Also add 3 to `_GAS_LPG_MAIN_FUEL_CODES` so the §15.0-lodged bottled-LPG
water fuel is adopted as the boiler's space-heating carrier (priority 1)
instead of the meter flag.
Effect: main_fuel_type=3 (bottled LPG) and water_heating_fuel=3 (was
None). Mains-gas certs still → 26 (full regression suite green bar the 3
pre-existing unrelated fails); the MissingMainFuelType tripwire still
fires for genuinely-undeterminable carriers.
Spec: SAP 10.2 Table 12 / RdSAP 10 Table 32 (PDF p.95) — bottled LPG
main heating fuel code 3.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`_elmhurst_dwelling_type` derived a flat's roof exposure from
`room_in_roof is not None`, so a top-floor flat whose roof is a plain
external "PS Pitched, sloping ceiling" (no room-in-roof) fell through to
"Mid-floor flat". The cascade's `_dwelling_exposure` then treats a
mid-floor flat's roof as a party ceiling (RdSAP 10 §5 / §3 — party
surfaces carry no heat loss) and drops the entire roof term: cert
001431's 105 m² roof at U=2.3 = 241.68 W/K (30) vanished, collapsing
(33) fabric heat loss 320.06 → 78.38 and over-rating SAP by ~5 points
(on top of the age-band roof-U bug — see prior commit).
Read the roof TYPE instead — the dual of the floor's "Another dwelling
below" signal. A flat's roof is a party ceiling only when its Elmhurst
code is S / A / NR (Same/Another dwelling or Non-residential space
above); F / PN / PA / PS are exposed external roofs, so the dwelling is
on the top storey. `has_exposed_roof = room_in_roof present OR
_elmhurst_roof_is_exposed(roof)` — which is exactly what the function's
own docstring already described as the intent ("RR present or external
roof"), now implemented.
With both upstream fixes the full chain (Summary PDF → extractor →
mapper → cert_to_inputs → calculator) reproduces the worksheet's §11a
unrounded SAP 56.3649 at abs < 1e-4, with (30)/(33)/(37) matching to
the decimal. Only flat fixture reclassified; 000784 (top-floor, RR) and
000910 (ground-floor) unchanged. Regression suite green bar the 3
pre-existing unrelated fails.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Forcing-function guards so a lodged-but-unmapped code surfaces loudly instead
of silently taking a wrong-but-plausible default (the class that hid single
glazing as U=2.5 until this session). Four silent fallbacks converted to raise
on PRESENT-but-unmapped codes, while keeping the legitimate ABSENT (None)
defaults:
- _api_glazing_transmission: unmapped glazing_type -> UnmappedApiCode (was
None -> u_window all-None default 2.5).
- _api_cascade_glazing_type: unmapped glazing_type -> UnmappedApiCode (was
pass-through -> wrong g-value slot).
- seasonal_efficiency: a lodged code/category resolving in neither
_SPACE_EFF_BY_CODE nor the category/room-heater fallbacks -> UnmappedSapCode
(was blind 0.80 gas-boiler default, which 'catastrophically misrates heat
pumps and storage' per the table comment). Data-free calls keep 0.80.
- water_heating_efficiency: WHC in no SAP 10.2 Table 4a HW row ->
UnmappedSapCode (was blind 0.78). Absent code keeps 0.78.
Zero current-corpus impact (909 computed / 0 raises, 56.66% within-0.5
unchanged) — the code/efficiency tables are complete for today's data, so
these are guards for the ongoing audit + future data refreshes. Verified the
WHC table already covers 908 (multi-point gas) and 950 (HW heat network), so
those are NOT unmapped-code bugs. 8 AAA tests, goldens + gate green, pyright
net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The g-value tables (_G_PERPENDICULAR_BY_GLAZING_TYPE solar g⊥,
_G_LIGHT_BY_GLAZING_CODE daylight g_L) are keyed on the SAP 10.2 Table 6b
cascade enum, but _api_cascade_glazing_type only translated code 1. Codes 4
and 5 sit in the 1-6 range where RdSAP-21 and the cascade enum disagree
(RdSAP-21 4=secondary/5=single vs cascade 4=double-low-E/5=secondary), so an
API single-glazed window read the cascade-5 secondary g (0.76/0.80) instead
of single (0.85/0.90), and a secondary window read cascade-4 double-low-E
(0.63). Added the {4:5, 5:1} remap entries the existing design comment
already anticipated ("only divergent codes need a remap").
Correctness fix: solar/daylight gains are second-order, so eval is unchanged
(56.66% within-0.5, 0 certs flip) — the dominant single-glazing error was the
U-value, closed in a0432977's Table 24 transmission map. This closes the
keying inconsistency to prevent future drift. 4 AAA tests, goldens + gate
green, pyright net-zero (38=38).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The API glazing-transmission table mapped only the double-glazing codes
[1,2,3,13,14]; single (5/15), secondary (4/11/12) and triple (6/8/9/10)
glazing codes returned None from _api_glazing_transmission, so the cascade
silently routed them to the u_window all-None default U=2.5 instead of their
RdSAP 10 Table 24 (spec p.50) value. Single glazing (U=4.8) was the worst:
modelled at half its true heat loss → systematic over-rate (cert 0370-2933,
7 single-glazed windows, +17 SAP).
Extended _API_GLAZING_TYPE_TO_TRANSMISSION + the gap-keyed override table
with the Table 24 (U, g, frame-factor) rows for every RdSAP-21 glazing code
(single 4.8/g0.85; secondary normal-E 2.9 / low-E 2.2 /g0.85; triple
pre-2002 2.4/2.1/2.0 by gap, 2002-2022 2.0, all g0.68/0.72; known-data
codes 7/8 alias their family default). 94 corpus certs carry an unmapped
glazing code (code 5 = 79); they sat at 32% within-0.5 vs 54.9% baseline.
Eval: within-0.5 54.90% -> 56.66% (net +16 certs: 22 in, 6 offsetting-error
out), within-1.0 70.2 -> 71.9%, mean|err| 1.224 -> 1.203, 909 computed / 0
raises. Spec-applied uniformly per the determinism principle. 7 AAA tests,
goldens + gate green, pyright net-zero (38=38).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Follow-up to the §2 MV-kind slice. Once MEV dwellings stopped
under-stating their ventilation HEAT loss, a +0.9 SAP over-rate residual
remained — the MEV FAN ELECTRICITY (§5 Table 4f line (230a),
`SFPav × 1.22 × V`, PCDB Tables 322 decentralised-MEV + 329 in-use
factors). `_mev_decentralised_kwh_per_yr_from_cert` already composes it,
but reads `epc.mechanical_ventilation_index_number` +
`epc.mechanical_vent_duct_type`, and the API builder
(`from_rdsap_schema_21_0_1`) never set either — so `pcdf_id is None`
short-circuited the fan energy to 0 on every API cert (the Summary/
Elmhurst path set them, so cert 000565 already billed it).
Wire both schema fields through the 21.0.1 API construction (the corpus
schema). Eval: the 9 MEV certs carrying a PCDB index closed +0.90 ->
+0.13 signed (fan electricity now billed); headline within-0.5 55.01% ->
55.12%, mean|err| 1.233 -> 1.232, 909 computed / 0 raises. Only those 9
certs move (clean diff). The 11 index-less MEV certs still sit at +1.36 —
they need the SAP Table 4h DEFAULT specific fan power (no PCDB record), a
separate slice.
New end-to-end test + fixture (cert 1300, Titon-class dMEV index 500777,
Flexible duct): from_api_response preserves the index + duct type and
(230a) resolves to a positive fan-energy contribution. Goldens + full
calc/epc regression green; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The profiler flagged `mechanical_ventilation=2` as a clean systematic
over-rate: 20 certs, signed +1.90 SAP, only 5% within 0.5 (every one
positive). Root cause: the API path (`from_api_response`) dropped the
doc-level `mechanical_ventilation` field, so `sap_ventilation.
mechanical_ventilation_kind` was always None and the §2 cascade
defaulted to NATURAL — under-stating the ventilation air-change rate
(and hence heat loss) for every mechanical system. (Only the Elmhurst/
Summary path mapped it, via `_ELMHURST_MV_TYPE_TO_KIND`.)
RdSAP-Schema-21 `mechanical_ventilation` enum (epc_codes.csv) →
MechanicalVentilationKind picking the SAP 10.2 §2 (24a..d) effective-ach
formula:
0 natural -> NATURAL (24d)
1 MV (no heat recovery) -> MV (24b)
2 mechanical extract, dc (MEV) -> EXTRACT_OR_PIV_OUTSIDE (24c)
3 mechanical extract, c (MEV) -> EXTRACT_OR_PIV_OUTSIDE (24c)
5 positive input from loft -> NATURAL (loft-sourced PIV adds no
system air change per RdSAP 10 §2.6)
6 positive input from outside -> EXTRACT_OR_PIV_OUTSIDE (24c)
Code 4 (MVHR, 24a) is DEFERRED — its formula needs the lodged
heat-recovery efficiency (PCDB Table 326) the API→cascade path doesn't
yet plumb; mapping it to MVHR with a null efficiency would mis-model it
as MV, so it stays NATURAL (3 scattered certs, accurate at the median).
Unmapped integers raise `UnmappedApiCode` (mirror of `_api_sheltered_
sides` / `_api_type_1_gable_kind`).
Eval: the extract cohort (mech_vent 2/3/6) moved +1.90 -> +0.9 median
(within-0.5 5% -> 35%); 20 improved / 3 regressed (offsetting). Headline
within-0.5 54.24% -> 55.01%, within-1.0 69.64% -> 70.08%, mean|err|
1.248 -> 1.233, 909 computed / 0 raises. The +0.9 residual on MEV is the
fan electricity (§2.6.4 SFP, PCDB Table 322) — a separate follow-up.
2 AAA tests; goldens + full calc/epc/parser regression green; pyright
net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Audit of the API-SAP error (53% within 0.5) localised the systematic
under-rate to ELECTRIC FLATS (houses sit at 60-66% within 0.5; electric
flats 13-19%). Decomposing the flat error showed it tracks space-heating
demand per m² — the worst certs reach 130-289 kWh/m² (accurate certs sit
at 14-110), i.e. a grossly over-stated fabric heat loss, amplified ~4x by
the electricity unit price and the steep low-band SAP log curve.
Root cause: the gov-EPC API lodges `sheltered_wall="Y"` on alternative
wall sub-areas (a sub-area adjacent to an unheated buffer — stair core,
adjoining structure), but the field was dropped by the schema + domain
dataclasses and the calculator billed the alt sub-area at its full
exposed U. RdSAP 10 Table 4 (PDF p.22) "Sheltered": such a wall carries
an added external surface resistance R=0.5 m²K/W → U_sheltered =
1/(1/U + 0.5) — the SAME adjustment the main wall already applies for
`gable_wall_type=2` (`gable_wall_sheltered`,
`_SHELTERED_GABLE_ADDED_RESISTANCE_M2K_W`). Cert 0340-2976 (band-A flat,
42 m² sheltered timber-frame alt) over-stated its wall channel by
~58 W/K → walls 128 -> 70 W/K.
Threads the field end-to-end: schema dataclasses (21.0.0/21.0.1) +
domain `SapAlternativeWall.is_sheltered` (default False — the Summary/
Elmhurst path leaves it False, sheltering rides through its lodged
U-value there, so goldens are untouched) + `from_api_response` mapping
`"Y"->True` + `_alt_wall_w_per_k` applying the 0.5 resistance on the
cascade path (lodged-U and basement alt-walls return before it).
140 certs (15% of the corpus) carry a sheltered alt-wall; they under-
rated at median -0.82 / mean signed -1.33 / 23% within 0.5. Eval: 102
improved, 38 regressed (offsetting-error cases — fix is spec-uniform per
[[feedback_software_no_special_handling]]); within-0.5 53.14% -> 54.24%,
within-1.0 67.99% -> 69.64%, within-2.0 81.85% -> 83.50%, mean|err|
1.312 -> 1.248, 909 computed / 0 raises. Goldens (6035, 000565) and full
calc/epc/parser regression green; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Pulls in 42 commits of calculator/mapper accuracy fixes from the per-cert
mapper-validation and floor/roof/heating fronts.
Conflict resolutions:
- mapper `_is_elmhurst_roof_window`: main dropped the branch's "wall location →
vertical" guard (it broke cert 000516's rooflight), but that re-broke cert
001431's two External-wall U>3.0 windows (which must stay vertical). The two
certs lodge a BYTE-IDENTICAL §11 row, so neither location nor U separates
them — the real discriminator is the room-in-roof context. Replaced the
unconditional U>3.0 backstop with one gated on the BP having a room-in-roof
(`_elmhurst_bp_has_room_in_roof`): 000516's Main BP has a "Room in roof type
1" (→ rooflight), 001431's does not (→ vertical). Validated against BOTH —
full Elmhurst worksheet suite 1038 pass + the 001431 window-extraction pin.
- property_postgres_repository: kept main's `ids_by_uprn` method + the branch's
`_restrictions_of` helper.
- sap_fuel.py: the branch relocated it to domain/billing/ (already carrying
main's to_table_32_code normalization), so kept the old path deleted.
Fallout from main's fabric fixes (validated by the boiler-3 real-cert pin which
still reproduces at delta 0):
- re-pinned the boiler-1 + boiler-instant-hw ASHP snapshot scores;
- main's §14.2 gas-boiler main-fuel derivation resolved the BGB/102 baseline
gap, so `test_gas_boiler_instant_hw_before_baselines` is now a passing test
(was an xfail tripwire).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Elmhurst §15.1 "Insulated: No Insulation" label was lodged but absent
from `_ELMHURST_CYLINDER_INSULATION_LABEL_TO_SAP10`, so
`_elmhurst_cylinder_insulation_code` raised UnmappedElmhurstLabel — blocking
the parse of every Solar PV example cert (the solar `before` lodges "No
Insulation"). An uninsulated cylinder has no insulation *type*, so per the
no-misleading-insulation convention it maps to `cylinder_insulation_type =
None` rather than naming a material; the lodged 0 mm thickness carries the
storage-loss signal the SAP 10.2 Table 2 dispatch needs.
Slice 1 of the Solar PV Recommendation Generator (ADR-0026).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The API `floor_heat_loss` code is authoritative — confirmed by joining each
single-BP cert's code to its independent `floors[].description` (which the
gov register publishes alongside the code):
code 1 ↔ "To external air" (exposed, 9/9)
code 2 ↔ "To unheated space" (semi-exposed, 6/6)
code 3 ↔ "(other premises below)" (partially htd, 9/9)
code 6 ↔ "(another dwelling below)" (party, 176/176)
code 7 ↔ "Solid"/"Suspended …" (ground, all)
Code 3 was mis-mapped to "To unheated space" (semi-exposed) and, on
mid-/top-floor flats, had its floor area zeroed entirely by the
dwelling-level exposure heuristic. RdSAP 10 §3.12 (PDF p.25) classes a
flat's floor over non-domestic "other premises … heated, but at different
times" as "above a partially heated space" → the §5.14 (PDF p.47) constant
U=0.7 W/m²K — distinct from semi-exposed (Table 20) and party (no loss).
Fix: the mapper sets `is_above_partially_heated_space` on the floor=0
dimension for code 3 (string → "(other premises below)" for fidelity), and
the heat-transmission step lets that per-BP lodgement override the flat
suppression upward (mirroring the existing exposed / "another dwelling
below" overrides). The cascade already routes is_above_partial → U=0.7.
Re-pins golden cert 7536-3827: its Ext2 (bp3) lodges code 3, but the cert's
lossy `floors[]` summary dropped that description, so a prior agent guessed
"code 3 = ground" (U=1.12) and concluded the residual was an irreducible
"register-rounding" artifact. It was this bug: Ext2 floor U 1.12 → 0.70,
PE -6.1952 → -5.6414, CO2 -0.1639 → -0.1492 (both toward 0), SAP unchanged.
Eval: 909 computed, 45.1% → 45.3% within 0.5, mean|err| 1.702 → 1.659,
<1.0 59.5% → 60.2%. 13 code-3 certs improve (0380 +3.71 → -0.63, 0350
+7.82 → +0.83, 2610 +7.47 → -1.29); the few that overshoot were already
failing and carry independent fabric bugs (9763's walls = 8 W/K for 60 m²).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
API floor_heat_loss=8 is observed on EXTENSION building parts whose
floor sits over a heated space within the SAME dwelling (an upper-storey
extension over a heated room). RdSAP 10 §3 gives an internal floor
between heated storeys no floor heat loss — mechanically identical to a
code-6 party floor. `_api_floor_type_str` had no entry for 8, raising
UnmappedApiCode and blocking certs 0370-2254-6520-2426-5971 and
0997-1206-9806-0715-2904.
Map code 8 to the code-6 no-heat-loss string "(another dwelling below)"
(consumed by heat_transmission's party-floor suppression; != "Ground
floor" so the §5 (12) suspended-timber rule stays inert). Empirically
confirmed against both certs: the no-heat-loss treatment lands them
within 0.5 of lodged (0370-2254 68.92 vs 69; 0997-1206 40.68 vs 41),
whereas Ground-floor / unheated / external mappings miss 0997 by ~4 SAP.
Eval computed 906→908. Regression green (only the pre-existing
test_total_floor_area fails); pyright net-zero (38=38).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A floor lodged API floor_heat_loss=6 ("another dwelling below") sits over
another heated dwelling, so it is a party floor with no heat loss (RdSAP
10 §3). The mapper mapped code 6 → None and the heat-transmission step
drove floor exposure solely from the dwelling-level `has_exposed_floor`
flag — which is keyed only on the dwelling_type label and defaults a
"Ground-floor flat" to an exposed floor. So a ground-floor flat above a
basement dwelling kept its full ground-floor heat-loss area.
Map code 6 → "(another dwelling below)" (still != "Ground floor", so the
§5 (12) suspended-timber rule stays inert) and have the cascade suppress
that BP's floor when its floor_type carries the signal, mirroring the
roof's existing "another dwelling above" per-BP party override.
Cert 2115-4121-4711-9361-3686 (ground-floor flat, floor_heat_loss=6):
floor_w_per_k 47.85 → 0; SAP -23.44 → -4.41. Cert 0350-…-6435 -12.38 →
-0.55; 0926-…-9024 -2.35 → -0.82. Eval mean |err| 1.982 → 1.944.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A Summary §14.0 Table 4b gas boiler (SAP code 101-119) lodges no §14.0
"Fuel Type" string in the newer Elmhurst export. The carrier was resolved
only from §15.0 "Water Heating Fuel Type" — fine when the same boiler
heats the water, but a gas boiler paired with a SEPARATE electric
immersion lodges §15.0 "Electricity", so `_elmhurst_gas_boiler_main_fuel`
returned None and the cascade strict-raised MissingMainFuelType.
Cert 001431 boiler-1/boiler-2 "before" variants are exactly this config:
§14.0 SAP code 102/104 (mains-gas boiler), §15.0 electric immersion
(code 909), §14.2 Meters "Main gas: Yes". The meter flag is the
authoritative carrier signal — a 101-119 boiler on mains gas burns mains
gas — so adopt it (SAP10 main_fuel 26 per _ELMHURST_MAIN_FUEL_TO_SAP10
"Mains gas") when §15.0 can't disambiguate. §15.0 gas/LPG still wins when
present (keeps LPG-vs-mains-gas precision); no mains-gas meter + non-gas
§15.0 still strict-raises rather than guessing.
Spec: SAP 10.2 Table 4b "Seasonal efficiency for gas and liquid fuel
boilers" (PDF p.168), rows 101-119. Both certs now resolve main_fuel=26
and compute (was: hard raise).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A "Pitched, sloping ceiling" (roof_construction == 8) lodges its
insulation in the dedicated `sloping_ceiling_insulation_thickness` field,
not `roof_insulation_thickness` (which stays None — the loft-joist field
is meaningless for a slope-following ceiling). The schema dataclasses
dropped that field, so `from_dict` discarded it and the cascade treated
the slope as uninsulated; worse, the pre-1950 None-fallback forced 0 mm
(U=2.30), over-stating roof heat loss ~74%.
Surface the field on SapBuildingPart (schemas 21.0.0 / 21.0.1) and prefer
it in `_api_resolve_sloping_ceiling_thickness` when it carries a NUMERIC
thickness: "100mm" now reaches Table 17 column (1a) "Insulated slope –
sloping ceiling, mineral wool/EPS" (RdSAP 10 §5.11.3 p.44 — 100 mm →
U=0.40) instead of 2.30. Categorical lodgements ("AB" As Built / "NI")
are not measured thicknesses, so they fall through to the existing
as-built rule (Table 18 col (3) via is_pitched_sloping_ceiling).
Cert 9884-3059-9202-7506 (code 8, age B, sloping 100 mm): SAP −5.54 → +0.06.
Cert 8036-2925-6600-0202: −4.94 → +1.55. No regressions in the roof-8
cohort (the "AB" certs are unchanged). Eval headline 43.8% → 44.3% within
0.5; golden fixtures incl. 6035 green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The 2026 API sample raised UnmappedApiCode on `gable_wall_type` 2 (10 certs)
and 3 (4 certs) — the two RR gable variants beyond Party(0)/Exposed(1).
Sim case 21 (an Elmhurst replica of API cert 2818-3053-3203-2655-9204:
gable_wall_type_1=2, gable_wall_type_2=3) lodges them as "Sheltered" and
"Connected", confirming **2=Sheltered, 3=Connected**.
- Mapper: `_API_TYPE_1_GABLE_TYPE_TO_KIND` gains 2 → `gable_wall_sheltered`,
3 → `connected_wall` (U=0, area deducts — already handled).
- Calculator: new `gable_wall_sheltered` branch. The API path lodges no
per-gable U, so the cascade DERIVES it as RdSAP 10 Table 4 (p.22)
Sheltered = 1/(1/U_wall + 0.5) — back-solved + validated against case 21
(U_wall 1.10 → 0.71) and case 20 (1.70 → 0.92). A lodged U (Summary path)
still rides through as an override.
API sample: 14 raises clear → `computed` 882 → 896, `raise:ValueError` 16 → 2.
Summary path unchanged (Sheltered stays `gable_wall_external` + lodged U, so
cert 000487's hand-built fixture is untouched). 2861 pass (lone
test_total_floor_area pre-existing); pyright strict net-zero (32=32 / 12=12).
NOTE: the derived Sheltered U on cert 2818 lands at 0.92 not 0.71 because the
cascade computes its 440 mm solid-brick wall U as 1.70 (the 220 mm default) —
a SEPARATE wall-U-vs-thickness bug (next slice, validated by case 21's 1.10).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
