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>
A mid-/top-floor flat whose lowest floor is lodged as an exposed floor
(API floor_heat_loss=1) had its floor area zeroed by the dwelling-level
exposure heuristic, which keys only on the flat label and defaults
has_exposed_floor=False (assuming the floor sits over another *heated*
dwelling). RdSAP 10 §3.12 (PDF p.25) is explicit:
"Otherwise the floor area of the flat ... is:
- an exposed floor if there is an open space below"
i.e. a flat cantilevered over a passageway IS a heat-loss floor on
Table 20. The per-BP `is_exposed_floor` lodgement is authoritative and
now overrides the dwelling-level suppression upward, mirroring the
existing "another dwelling below" party override (which suppresses
downward). The code-1↔"E To external air" enum is confirmed by the
paired API+Summary worksheet certs (0350, 3800).
Eval: 45.1% → 45.3% within 0.5 (909 computed); cert 3836 +6.79 → +0.77,
5717 +1.31 → -0.07 and 0997 +0.76 → +0.05 cross into <0.5. Two
already-failing under-rated certs (7636, 2241) shift further — both are
dominated by independent cost-side over-counts the exposed floor merely
unmasks (7636 walls = 8.98 W/K for 33.87 m² is the real defect).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The main pitched/flat roof U-value was derived from the JOINED text of
every roofs[] entry. A room-in-roof carries its own §3.9/§3.10 shell
area + U-value cascade (Table 17 / Table 18 col 4), so a multi-roof cert
lodged "Pitched, insulated (assumed) | Roof room(s), no insulation
(assumed)" leaked the RR's "no insulation" marker into the main roof's
u_roof → U=2.30 applied to the WHOLE main roof, ~3x over-stating its heat
loss. This is the 4700-family regular-roof-U leak.
`_joined_main_roof_descriptions` drops "Roof room(s)" entries before the
main-roof u_roof, falling back to the unfiltered join only for pure-RR
dwellings (every entry an RR) to preserve their prior behaviour. The RR
shell U is unaffected (computed separately) — golden 6035 stays green.
RR-leak cluster (18 certs, RR "no insulation" + a non-RR primary roof):
mean |err| 6.14 → 4.85, within-1.0 0 → 8, within-0.5 0 → 3. Eval headline
44.8% → 44.9%, mean |err| 1.851 → 1.824, mean signed -0.152 → -0.081. Two
certs overshoot (other residuals the leak was masking); the spec rule is
applied uniformly.
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 440 mm (>420 mm) solid brick AS-BUILT wall computed U = 1.70 (the
220 mm bucket default) instead of the RdSAP-correct 1.10. The §5.7
Table 13 thickness path only fired for *insulated* brick (external/
internal + thickness > 0); the as-built case fell through to the
Table 6 cavity/solid age-band default.
Spec: RdSAP 10 Specification (9th June 2025), §5.7 "U-values for
uninsulated brick walls, age bands A to E", Table 13 (PDF p.40):
≤200 mm → 2.5, 200–280 mm → 1.7, 280–420 mm → 1.4, >420 mm → 1.1.
Table 6 footnote (b) on the "Solid brick as built" row (PDF p.40):
"Or from 5.7 if wall thickness is other than 200mm to 280mm" — the
thickness table supersedes the flat 1.7 default whenever a documentary
wall thickness is lodged (200–280 mm gives 1.7 either way). The §5.8 /
Table 14 dry-lining R is added on top only when the wall is dry-lined,
per the §5.7 closing sentence.
Validated against the user-generated Elmhurst worksheet "simulated
case 21" (replica of API cert 2818-3053-3203-2655-9204: mid-terrace,
age band B, solid brick as-built 440 mm, room-in-roof). New §3 cascade
pin `test_section_3_wall_u_by_thickness_case21_match_pdf` routes the
Summary through the real extractor + mapper and pins:
(31) 155.1000, (33) 175.6208, (36) 23.2650, (37) 198.8858 — all 1e-4.
External walls Main U → 1.1000; Sheltered RR gable → 1/(1/1.10+0.5) =
0.71 (was 0.92). Pinned on §3 only (case-6 precedent): its code-908
instantaneous multi-point gas water heater has a separate §4 (219) gap.
Cross-check: sim case 20 (220 mm) stays at 1.70 — unchanged.
API SAP accuracy (scripts/eval_api_sap_accuracy.py, 896 computed certs):
% |err| < 0.5 SAP vs lodged: 42.6% → 43.8%; mean |err| 2.045 → 2.010.
Regression: tests/domain/sap10_calculator/ (1861), backend/
documents_parser/tests/ (574), datatypes/epc/ + rdsap golden fixtures
all green (pre-existing test_total_floor_area excepted). pyright strict
net-zero. No solid-brick fixture pin shifted (200–280 mm unchanged).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Locks sim case 20 (storage heaters + Detailed RR + loose-jacket cylinder)
as a golden vector: _elmhurst_worksheet_001431_case20.build_epc() routes the
Summary PDF through extractor → mapper → calculator, registered in
test_e2e_elmhurst_sap_score with all 11 SapResult headline pins at 1e-4.
10 pinned exact off slices 1-2 (window extractor, RR stud walls); this slice
closes the last one, co2_kg_per_yr (was 3797.62 vs (272) 3815.4060).
Root cause: on a dual-rate (E7) meter the CO2 path ignored the tariff's
high/low Table-12 electricity codes that the cost path already uses:
- Secondary (direct-acting portable heaters, on-peak) keyed the monthly
Table 12d cascade on standard code 30 (0.15405) instead of the E7 HIGH
code 32 → (263) 0.1616. SAP 10.2 Table 12a Grid 1 direct-acting electric
is 100% high-rate; mirrors the cost side billing it at 15.29 p/kWh.
- Main storage heaters fell through `_table_12a_system_for_main`=None to
the FLAT annual factor (0.136) rather than the dual-rate LOW code: per
the Table 12a design intent ("storage … 100% low rate") they charge
off-peak → E7 LOW code 31 → (261) 0.1357.
case-20 co2 now EXACT. 2433 calculator + 112 golden + documents_parser tests
pass — no dual-meter/storage cohort regression; pyright strict net-zero (32=32).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
ADR-0014 BillDerivation attributes each end-use (HEATING / HOT_WATER /
SECONDARY / APPLIANCES / COOKING) to a fuel carrier and credits PV
export. SapResult already carried the per-end-use kWh but not WHICH
fuel each end-use burns, nor the annual exported kWh — so a downstream
SapResult->EnergyBreakdown adapter could not pick the right tariff.
Surfaces five output-only fields, threaded exactly like the recently
merged appliances/cooking change (2f039aeb):
main_heating_fuel_code RdSAP10 Table 32 / SAP 10.2 Table 12 fuel
main_2_heating_fuel_code code column (the lodged fuel code, e.g.
secondary_heating_fuel_code mains gas 26). None when the corresponding
hot_water_fuel_code system is absent / fuel not resolvable.
pv_exported_kwh_per_yr SAP 10.2 Appendix M1 §3-4 annual export kWh
(0.0 when no PV).
cert_to_inputs.py populates the four fuel codes from the existing
resolvers the cost/CO2 cascade already uses — `_main_fuel_code`,
`_secondary_fuel_code`, `_water_heating_fuel_code` (not reinvented);
Main 2 is the second `main_heating_details` entry, guarded for length.
There is a single CalculatorInputs construction site (cert_to_demand_
inputs delegates to cert_to_inputs). `pv_exported_kwh_per_yr` already
existed on CalculatorInputs; SapResult collapses its Optional to 0.0.
HARD CONSTRAINT honoured — output-only, zero rating drift. These fields
do NOT feed ECF / total_fuel_cost_gbp / co2_kg_per_yr / primary_energy_*
/ sap_score / any monthly value. Every golden-fixture, Elmhurst e2e
SapResult pin, section cascade pin, and heating-corpus residual stays
byte-identical: calculator suite 1658 -> 1661 passed (+3 new tests),
4 skipped, 0 failed before and after. pyright net-zero (51 -> 51 in
domain/; no new errors in the touched test files).
New tests: a synthetic threading test (four fuel codes + PV export pass
unchanged through calculate_sap_from_inputs; None PV collapses to 0.0)
and a cert-level pin (mains-gas combi cert 000516 -> main fuel code 26,
no Main 2, secondary 30, HW 26). Synthetic CalculatorInputs / SapResult
fixtures updated for the new SapResult fields (defaults cover Inputs).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The gov-EPC API mapper sets BOTH roof_construction (int) and
roof_construction_type (str, derived via _API_ROOF_CONSTRUCTION_TO_STR),
but the Elmhurst mapper set only the string — leaving roof_construction
None on every site-notes cert. The SAP cascade reads the STRING (so SAP
cross-mapper parity always held), but consumers of the int (e.g.
domain/sap10_ml/transform.py ML aggregates `main_dwelling_roof_
construction`) silently saw None on the Elmhurst path.
New `_elmhurst_roof_construction_int` maps the Elmhurst roof-type code to
the same SAP10 int the API lodges (F→1, PN→3, PA→4, PS→8, S/A→7),
harvested from the committed Summary fixtures. Unlike the wall map it
returns None (not a strict-raise) for unmapped codes: the int is not
cascade-load-bearing, so an unknown roof must not block the cert (vaulted
5 / thatched 6 / NR omitted until a fixture surfaces them).
The 6 hand-built U985 reference fixtures gain the matching
roof_construction int (4/4/3 etc.) so test_from_elmhurst_site_notes_
matches_hand_built_* still asserts structural parity. SAP output is
unchanged (cascade reads the string). §4 suite green (2407 passed); the
two pre-existing stone-§5.6 sap10_ml failures are unrelated/out of scope.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RdSAP10 `wall_construction == 6` is canonically WALL_SYSTEM_BUILT — a
WALL TYPE — but the gov-EPC basement heuristic hijacked it: Elmhurst
lodges both "SY System build" and "B Basement wall" as code 6, and the
API lodges basements as code 6 too, so a system-built wall was
mis-flagged `main_wall_is_basement` → wrong RdSAP §5.17 / Table 23
u_basement_wall/u_basement_floor overrides, and downstream the solid-wall
Recommendation Generator couldn't offer EWI/IWI on system-built walls.
System-built stays the wall type on its canonical code 6; the basement
signal moves OFF code 6 to a dedicated `is_basement` (SapAlternativeWall)
/ `wall_is_basement` (SapBuildingPart) Optional[bool] flag:
- Elmhurst: `_elmhurst_wall_is_basement` sets it from the distinct
"SY"/"B" labels (False for SY, True for B, None otherwise).
- gov-EPC API: per-wall code 6 can't be told apart at lodging time, so
`from_api_response` post-processes via `_clear_basement_flag_when_
system_built` — when the cert addendum marks the dwelling system-built,
the code-6 basement heuristic is cleared. A genuine basement (no
addendum signal) keeps the code-6 fallback.
- `main_wall_is_basement` / `is_basement_wall` honour the flag when set,
else fall back to the code-6 heuristic — so untouched API basements and
the cert 000565 "B" cohort are unchanged.
`EpcPropertyData.system_build` is a derived property over the wall type:
the MAIN wall is system-built iff `wall_construction == 6` and it is not
flagged basement. System-built lives on `wall_construction`; the basement
attribute is separate.
Acceptance: a system-built main wall (Elmhurst SY, or API addendum
system_build) → wall_construction == 6, main_wall_is_basement is False,
system_build is True; a genuine basement main wall → main_wall_is_basement
is True, system_build is False. Full §4 suite green (2404 passed).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
Golden cert 0390-2954-3640 (detached, TFA 360, age F) carried a +7 SAP /
-28 kWh/m² PE residual the audit attributed to a demand-side fabric gap.
Walking the §3 cascade localised it to the Main wall: lodged
wall_construction=4 (cavity), wall_insulation_type=4 (as-built / assumed),
description "Cavity wall, as built, partial insulation (assumed)". The
cascade mis-routed it to the Table 6 "Filled cavity" row (band F = 0.40)
because `_described_as_insulated` matches the "partial insulation"
substring.
RdSAP 10 Specification (10-06-2025) Table 6 — Wall U-values, England
distinguishes two cavity rows:
"Cavity as built" A-E 1.5, F 1.0, G 0.60, H 0.60, I 0.45, J 0.35, ...
"Filled cavity" A-E 0.7, F 0.40, G 0.35, H 0.35, I 0.45†, J 0.35†, ...
An "as built ... partial insulation (assumed)" cavity is the as-built
partial fill of the age band, NOT a retrofit cavity fill (a genuine fill
lodges the distinct "Cavity wall, filled cavity", wall_insulation_type=2).
It therefore routes to "Cavity as built" (band F = 1.0), mirroring the
worksheet-validated solid-brick rule in S0380.209 (cases 9/10: "as built,
insulated (assumed)" → as-built age-band row, not retrofit).
New `_cavity_described_as_filled` predicate is used only in u_wall's
cavity filled-row branch; it excludes the "partial insulation" substring
while keeping "insulated (assumed)" → filled (the unrelated, separately
asserted test_cavity_as_built_insulated_assumed_uses_filled_cavity_row is
unchanged). The shared `_described_as_insulated` (also consumed by the
roof/floor paths) is left untouched.
Wall HLC +53.6 W/K (U 0.40 → 1.0 over ~268 m²) lifts all four metrics
together — the signature of a real fabric bug, not a tuned offset:
SAP +7 → +0
PE -27.9745 → +0.5281 kWh/m²
CO2 -2.7134 → -0.1189 t/yr
Bands I-M are unaffected (the two rows coincide per the † footnote), so
golden certs 0535 (band M) / 7536 (band L) with "insulated (assumed)"
cavities continue to pin at 0. Full suite 2384 passed, 1 skipped.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The EPC renders a recent-band as-built wall as "<material>, as built,
insulated (assumed)". The API mapper populates epc.walls with that string,
and heat_transmission's wall_ins_present gate keyed off the "insulated"
substring → routed the wall to the RdSAP 50 mm "insulation of unknown
thickness" bucket (e.g. sandstone band J U=0.25) instead of the as-built
age-band row (U=0.35).
Per RdSAP 10 Table 8/9 footnote the 50 mm row applies ONLY when insulation
is "known to have been increased subsequently (otherwise 'as built'
applies)". An "as built ... (assumed)" description is the EPC's age-band
assumption — it only renders on RECENT bands (an old band renders "no
insulation (assumed)"), so the as-built row applies. Genuine retrofit is
signalled by wall_insulation_type (External/Internal/Filled), which the
gate still checks independently.
Worksheet-validated by two new Elmhurst worksheets, both As Built band J:
- simulated case 9: sandstone → (29a) U 0.35
- simulated case 10: solid brick → (29a) U 0.35
both the as-built row, NOT 50 mm (0.25).
Fix: restrict the description-based gate to genuine retrofit via the new
local `_described_as_retrofit_insulated` (excludes "as built"/"(assumed)").
The cavity filled-row routing inside `u_wall` (which uses
`_described_as_insulated` directly) is untouched — the 3 cavity API certs
(0390/0535/7536) are unaffected.
test_heat_transmission: the old `..._uses_50mm_row` test asserted 50 mm via
an IMPOSSIBLE band-B + "insulated (assumed)" combination; corrected to a
valid recent-band (J) scenario asserting the as-built row (35 W/K).
Golden 0240: walls 24.45 → 34.23 W/K (U 0.25 → 0.35). SAP integer 72
unchanged; PE residual re-pinned +1.8687 → +5.5044, CO2 +0.0907 → +0.2757.
This spec-correct fix REMOVED the wall under-count that was masking the
Ext1 vaulted-roof over-count (cascade U 0.68 via the same "insulated
(assumed)" description vs case-9 sloping-ceiling 0.25) — that roof
over-count is the next slice; fixing both lands SAP cont ≈ 72.31 (=
Elmhurst case 9).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds simulated case 7: case 6 (P960-0001-001431) with the heating swapped
to a CONDENSING OIL COMBI (SAP code 130, Table 4b 82/73) and the cylinder
removed — combi instantaneous DHW (WHC 901), Table 3a keep-hot combi loss
(61) = 600 kWh/yr, no primary/storage loss, boiler interlock PRESENT (no
−5pp). This is the heating archetype golden cert 0240-0200-5706-2365-8010
uses, which case 6 (SAP code 127, a *regular* condensing oil boiler +
cylinder) never exercised.
The cascade reproduces the case-7 worksheet EXACTLY at abs=1e-4 on every
top-level SapResult output with ZERO calculator changes:
(211) 7865.4304 (213) 7556.9821 (219) 3496.8121 (98c) 12646.3783
(255) 1123.3372 (257) 1.9631 (272) 5738.9315 (258) 73
This validates the SAP 10.2 Appendix D Eq D1 combi efficiency blend +
Table 3a keep-hot combi loss + Table 4b code 130 (82/73) path, and
exonerates the combi mechanism as the source of 0240's API-path residual
— which therefore lives in 0240's fabric/demand or the API mapper.
Test-only slice (no impl change). New fixture file: 0 pyright errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
With S0380.201-206 closing every line ref, the detached dual-oil case 6
(Main 1 radiators 51% / Main 2 underfloor 49%, different parts, no boiler
interlock, 6 roof-of-room rooflights) now matches its P960-0001-001431
worksheet to 1e-4 on the whole SapResult. Registered in
`test_e2e_elmhurst_sap_score.py::_FIXTURE_PINS` (11 pins):
SAP 72 / cont 71.6597, ECF 2.0316, cost 1162.5374, CO2 5953.6679,
space heat (98c) 11991.9611, main fuel (211)+(213) 14736.9564,
HW (219) 4902.8601, lighting (232) 357.6571, pumps (231) 356.0.
This was the validation target the S0380.200 handover set. Updated the
fixture docstring's stale "§3-windows-only" scope note.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Appendix D §D2.1(2) Equation D1 blends the monthly water-heater
efficiency by the ratio of the boiler's space-heating load to its water
load. On a dual-main cert the DHW boiler does only its OWN share of space
heating ((204) for Main 1, (205) for Main 2), but the cascade fed Eq D1
the dwelling total ((202) = 1 − secondary). That over-weighted η_winter
and under-stated HW fuel — simulated case 6 (Main 1 serves DHW + 51% of
space heat) was HW −78 kWh vs the worksheet.
New `_water_heating_main_space_fraction` returns the DHW main's total-
space share via `_water_heating_main` (WHC-901 → Main 1 (204); WHC-914 →
Main 2 (205)); single-main / WHC-901 single systems get (202) = 1 −
(201), so they are unchanged. Case 6 (219) HW now 4902.8601 EXACT.
With S0380.205 (demand exact), case 6 now closes to 1e-4 on EVERY metric:
SAP cont 71.6597, ECF 2.0316, cost 1162.5374, (211)+(213) 14736.9564,
(219) 4902.8601, (231) 356, (232) 357.6571, CO2 5953.6679 (rating) /
4895.2137 (demand).
Re-pin: 0240 (dual combi, WHC 901, Main 1 51%) HW rises slightly → PE
+1.6893 → +1.8687, CO2 +0.0815 → +0.0907 (SAP 72 unchanged). Single-main
certs unchanged (2360 pass + 0 fail).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
When two main heating systems heat different parts of a dwelling, SAP
10.2 §7 (PDF p.186) adapts the mean-internal-temperature calculation:
- Table 9b weighted responsiveness: R = (1−(203))·R_sys1 + (203)·R_sys2.
- Rest-of-dwelling temperature (90)m = weighted average of T2 computed
under EACH system's control schedule, weights (203)/[1−(91)] for sys2
and [1−(203)−(91)]/[1−(91)] for sys1 (or sys2's control alone when
(203) ≥ 1−(91)).
The cascade used Main 1's control + R=1.0 for the whole dwelling,
over-stating MIT by +0.037 °C on simulated case 6 (Main 1 radiators/2106
type 2 living + Main 2 underfloor/2110 type 3 elsewhere, R 1.0/0.75). That
inflated (97) heat loss by ~11 W → demand +61 kWh/yr.
`mean_internal_temperature_monthly` gains `main_2_control_type`,
`main_2_fraction`, `main_2_responsiveness`; cert_to_inputs derives them
from the second main detail (gated on main_heating_fraction > 0, so
single-main / DHW-only second mains pass the defaults → unchanged).
Case 6: (87) living, (90) elsewhere, (98c) demand 11991.96 and per-system
fuel (211)=7741.6458 / (213)=6995.3106 all match the worksheet to 1e-4.
Re-pin: golden 0240 (same 2106/2110 archetype, API-only) — PE +2.1519 →
+1.6893, CO2 +0.1051 → +0.0815 (both closer to zero; SAP 72 unchanged).
Single-main certs unchanged (2360 pass + 0 fail).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Prerequisite for the SAP 10.2 p.186 two-systems-different-parts MIT.
When two main systems heat different parts of a dwelling, §14.1 Main
Heating2 lodges its OWN "Heat Emitter" + "Main Heating Controls Sap"
(simulated case 6: Main 1 radiators / control 2106 serving the living
area, Main 2 underfloor / control 2110 serving elsewhere). The extractor
+ mapper dropped both — `MainHeatingDetail.heat_emitter_type` and
`main_heating_control` came through as empty-string sentinels, so the
cascade saw system 2 as having no responsiveness (defaulted R=1.0) and no
control type.
- `MainHeating2` datatype gains `heat_emitter` + `heating_controls_sap`.
- The extractor reads them from the §14.1 block.
- `_map_elmhurst_main_heating_2` maps them via the same helpers as Main 1
(`_elmhurst_heat_emitter_int` → underfloor-in-screed = emitter 2, Table
4d R=0.75; `_elmhurst_sap_control_code` → 2110, Table 4e type 3),
threading the dwelling floor + age band for the underfloor subtype.
Empty-string fallback preserved for the legacy DHW-only Main 2 (cert
000565 §14.1 omits emitter/control). No cascade output changes yet — the
MIT consumer lands in S0380.205. Full suite 2358 pass + 0 fail.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A rooflight deducts from the gross area of the roof element it pierces
(RdSAP 10 §3.7, PDF p.19). A "Roof of Room" rooflight (window_wall_type=4
/ site-notes "Roof of Room") sits on the room-in-roof sloped ceiling, so
its area must deduct from the §3.10.1 RR residual roof — not the flat /
loft external roof.
The cascade deducted every rooflight from the regular roof (heat_
transmission line 814). Simulated case 6's worksheet is the first
worksheet evidence for "Roof of Room" rooflight billing: "Roof room Main
remaining area" net 55.54 = gross 61.73 − 6.19 rooflights (U_RR=0.30),
while "External roof Main" 14.52 carries no opening. New
`_bp_rr_roof_absorbs_rooflight` routes the rooflight area to the RR roof
(simplified A_RR_final or detailed §3.10.1 residual) ONLY when the BP's
RR contributes such a shell AND lodges no explicit roof surface (slope /
flat_ceiling / stud_wall). Case 6 roof (30) 20.2284 → 19.0523 EXACT;
demand gap +153 → +61 kWh/yr.
Preserved: certs 000565 (Ext2 stud walls) and 000516 (slopes) lodge
explicit roof surfaces → rooflight keeps deducting from the regular roof
(their 1e-4 worksheet pins hold). Simplified Type 1 RR is excluded too.
Re-pin (uniform spec application per [[feedback-software-no-special-
handling]] + worksheet-is-truth): API certs 6035 and 0240 are detailed-RR
gables-only like case 6 (no worksheet of their own for rooflights), so
their "Roof of Room" rooflights now deduct from the RR residual too. This
SUPERSEDES the unvalidated S0380.198 "deduct from loft" assumption.
- 6035: roof 78.0648 → 73.9176; the previously-"unexplained" +1.37 PE
residual COLLAPSES to -0.14 (CO2 -0.0004 → -0.0362; SAP exact 70) —
strong corroboration the rooflight-on-RR treatment is correct.
- 0240: PE +2.5812 → +2.1519, CO2 +0.1269 → +0.1051 (SAP 72 unchanged).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The §5 (70) internal-gains mirror of S0380.201's Table 4f (230c). SAP
10.2 Table 5a note a) (PDF p.177) verbatim: "Where there are two main
heating systems serving different parts of the dwelling, assume each has
its own circulation pump and therefore include two figures from this
table. ... Where two main systems serve the same space a single pump is
assumed."
Simulated case 6 (dual oil, 51% radiators + 49% underfloor) lodges Main
1 "2013 or later" (3 W) + Main 2 unknown date (7 W) → worksheet (70) =
10 W in the 8 heating months. The cascade billed a single Main 1 pump
(3 W). New `_second_main_central_heating_pump_gain_w` adds the second
main's gain (at its own pump-age bucket), gated on a lodged
main_heating_fraction > 0 — the same genuine-second-space-heating-main
test as S0380.201, so DHW-only second mains (cert 000565 Main 2 combi via
WHC 914, fraction 0) keep a single pump (70)=3. Refactored the per-detail
pump predicate (`_main_detail_has_central_heating_pump`) and date bucket
(`_pump_date_category_for_detail`) out of the orchestrator.
Re-pin: golden 0240 (dual-main oil combi, both unknown date) (70) 7 → 14
W; the extra internal gain lowers space-heating demand → SAP cont 72.18 →
72.24 (integer 72 unchanged), PE +2.8092 → +2.5812, CO2 +0.1385 →
+0.1269 (both closer to zero). Validated against the case-6 worksheet.
This closes the (70) leg of case 6's space-demand gap. Remaining for full
case-6 closure: roof fabric (37) +1.176 W/K (room-in-roof shell) and HW
(216) Eq-D1 water efficiency −1.6%.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Simulated case 6 (P960-0001-001431, dual oil boiler 51% rads + 49%
underfloor) worksheet (231) = 356 = (230c) central-heating pump 156 +
(230d) oil boiler pump 200. (230c) decomposes per SAP 10.2 Table 4f
note c) (PDF p.175): "Where there are two main heating systems include
two figures from this table" — Main 1 41 kWh (pump age "2013 or later")
+ Main 2 115 kWh (pump age unknown). The cascade summed only Main 1's
circulation pump, giving (231) = 241.
cert_to_inputs now adds the second main's circulation pump, gated on a
lodged main_heating_fraction > 0 (a genuine second SPACE-heating main —
the same test §9a uses to split space-heating demand). This excludes
DHW-only second mains (cert 000565 Main 2 = gas combi via WHC 914,
fraction 0); without the gate 000565's worksheet pins regressed +115 kWh.
Re-pin: golden 0240 (dual-main oil combi, API-only, no worksheet) gains
its Main 2 pump too (pumps_fans 315 → 430). Spec-correct per
note c and validated by the case-6 worksheet; SAP cont 72.55 → 72.18
(integer 73 → 72, resid +0 → -1), PE +1.9459 → +2.8092, CO2 +0.1226 →
+0.1385. The lodged 73 carries Elmhurst's own residual; the worksheet-
backed case 6 is the spec authority for the archetype.
Note: the boiler-interlock −5pp per-main determination the prior
handover flagged as the priority is already implemented (S0380.141
cylinder-thermostat path + S0380.177 room-thermostat path) — case 6
already produces (206)=79 / (207)=84 exactly, and 0240 is a combi with
no cylinder so correctly unpenalised.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The cascade lumped a dwelling with two main heating systems into one:
`space_heating_fuel_monthly_kwh` hard-coded (203)=0 (a documented
scope-A placeholder) and the calculator's per-month fuel read only
main_1, so the full §8 space-heat demand billed against system 1's
efficiency. Simulated case 6 (one oil boiler feeding radiators 51% +
underfloor 49%) exposed it: main fuel ≈ demand/eff1 instead of the
worksheet's (211)+(213) per-system split.
Implements the SAP 10.2 §9a two-main model:
(204) = (202) × (1 − (203)) → system 1 share of total heat
(205) = (202) × (203) → system 2 share of total heat
(211)m = (98c)m × (204) × 100 / (206)
(213)m = (98c)m × (205) × 100 / (207)
(203) = the second system's lodged `main_heating_fraction`; (207) = its
own seasonal efficiency via the new per-detail `_main_heating_detail_
efficiency` (the core of `_main_heating_efficiency`, now reused for
system 2). Calculator `_solve_month` aggregates main_1 + main_2 into
`main_heating_fuel_kwh`. Cost (§10a 241), CO2 (§12 262) and PE (§13 276)
main_2 paths were already wired and now activate.
Site-notes gap also fixed: §14.1 Main Heating2 omits the "Fuel Type"
cell when the second system shares Main 1's fuel (case 6: one oil boiler,
two emitters). `_map_elmhurst_main_heating_2` now inherits Main 1's
resolved fuel as a fallback.
Blast radius: only dual-main certs. 0240 (2× oil code 130, identical
Eq-D1 efficiency) is unchanged — its split collapses to the lumped total.
Suite: 2355 passed, 1 skipped. New code: 0 pyright errors.
NOTE: case 6 is not yet fully pinnable end-to-end — its two systems have
DIFFERENT efficiencies (radiators 55°C → 79%, underfloor 35°C → 84%), a
flow-temperature boiler-efficiency adjustment not yet modelled, and its
dual-system auxiliary pumps ((230c)+(230d)=356) differ from the cascade.
Both are separate follow-on features; this slice is the §9a fuel split.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Elmhurst extractor crashed parsing simulated-case-6's room-in-roof
window rows: the §11 "Location" cell "Roof of Room in Roof" wraps across
the layout prefix/suffix blocks and leaked into the glazing-type phrase
("Double between 2002 Roof of Room and 2021 in Roof" → UnmappedElmhurst-
Label). Fix (`_parse_window_from_anchors`): detect the roof-of-room
location tokens, strip them from the before/after blocks so the glazing
phrase reconstructs cleanly, and set location="Roof of Room".
Mapper: `_is_elmhurst_roof_window` gains a "Roof of Room" location branch
(highest-confidence rooflight signal, above the BP-roof-type / U>3.0
gates); `_ELMHURST_ROOF_WINDOW_U_BY_GLAZING` gains "Double between 2002
and 2021" → 2.30 (case 6 lodges the already-inclined roof-window U, so
the +0.30 inclination adjustment must not double-apply).
This is the site-notes mirror of S0380.198 (API window_wall_type=4):
both paths now route room-in-roof rooflights to (27a) at the inclined U.
Validated against the case-6 P960 worksheet at abs=1e-4:
(27) Windows = 22.7408 (cascade 22.7407)
(27a) Roof Windows = 13.0375 (cascade 13.0375, EXACT)
(31) ext area = 336.13
Case 6 is pinned only on the §3 window line refs (new standalone test,
not added to the section-pin `_FIXTURES`) because its DUAL main heating
(51% rads + 49% underfloor, oil) makes the §10/§12 per-system lines
non-comparable to SapResult's aggregated fields — documented in the
fixture module. Summary mirrored to Summary_001431_case6.pdf.
Suite: 2355 passed, 1 skipped. New code: 0 pyright errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Promotes user-simulated "case 5" (detached, sandstone-walled, room-in-roof
cousin of golden cert 0240) to an e2e worksheet fixture pinning the WHOLE
extractor → mapper → calculator pipeline at abs=1e-4 on all 11 Block-1
line refs. Its worksheet prints the exact RR-gable routing S0380.196
implements, validating that fix against ground truth:
Roof room Main Gable Wall 1 15.68 U=0.35 (29a) Exposed → walls @ main-wall U
Roof room Main remaining area 61.73 U=0.30 (30) A_RR shell − Σ gables
External roof Main 14.52 U=0.11 (30) loft residual
Roof room Main Gable Wall 2 15.68 U=0.25 (32) Party → party @ 0.25
gable area = 6.40 × 2.45 (§3.9.1 default RR storey height); A_RR remaining
= 12.5√(83.2/1.5) − 2×15.68 = 93.09 − 31.36 = 61.73 (RdSAP 10 §3.9.1(e)).
Confirms a DETACHED dwelling can lodge a Party RR gable (Table 4 p.22
row 2) — so my S0380.196 mapping (gable_wall_type 0=Party, 1=Exposed) is
correct; do not flip it.
Two extractor/mapper gaps surfaced and fixed (case 5 is the forcing test):
- Sandstone wall label "SS Stone: sandstone or limestone" had no
`_ELMHURST_WALL_CODE_TO_SAP10` entry (raised UnmappedElmhurstLabel).
Added "SS" → 2 (WALL_STONE_SANDSTONE), matching 0240's API
wall_construction=2 (cross-mapper parity).
- Roof "Insulation Thickness 400+ mm" was silently dropped: the four
thickness parsers used `.split()[0].isdigit()`, which rejects the
trailing "+" → None → u_roof fell back to the age-J default 0.16
instead of 0.11 (+1.09 W/K roof, the whole 0.12 SAP gap). Added
`_parse_thickness_mm` (strips to leading digits) and applied it at all
four sites (walls / alt-wall / roof / floor). The only existing fixture
with "400+ mm" (000565 Stud Wall) routes via the RIR regex, unaffected.
Result: case 5 cascade ≡ worksheet at 1e-4 on SAP/ECF/cost/CO2 + every
energy stream. Neither gap affects 0240 (its API path captures both the
sandstone code and "400mm+"); 0240's residual is therefore non-fabric.
Suite: 2353 passed, 1 skipped. New code: 0 pyright errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the user-simulated case-4 worksheet as e2e fixture `001431_6035` —
reproduces golden cert 6035's full floor geometry (Main ground-floor HLP
15.99 + first-floor HLP 8.32, the asymmetric upper storey) and 8 windows.
All 11 Block-1 line refs pin at abs=1e-4 against the worksheet (SAP 68,
ECF 2.2802, cost 937.2341, CO2 4682.3494, space 15745.3260, main fuel
18744.4357).
This is the 4th independent 1e-4 confirmation across the 6035 archetype
(sim cases 1-4). Case 4 matches 6035 on floors + window areas; the
residual ~50 kWh / £11 cascade delta vs 6035 is two lodged inputs only
(largest window orientation N vs S; meter type "Dual" vs API 2), not
calculator behaviour.
Conclusion: the cascade reproduces the spec engine exactly for 6035's
geometry, so 6035's +19 PE vs the lodged register is lodged-register
divergence (the gov.uk register's rounded value vs the spec-exact
worksheet), NOT a calculator gap. 6035 is a "pin-forever" lodged-only
cert. Bugs surfaced + fixed along the way: S0380.192 (Simplified-RR
remaining area) and S0380.193 (suspended-floor sealed rule).
2341 passed (+11), 0 failed; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the user-simulated case-3 worksheet as e2e fixture `001431_rr8` —
Main + Extension + Simplified room-in-roof with 8 windows (≈14.15 m²,
reproducing golden cert 6035's glazing) and Main ground-floor HLP 15.99.
All 11 Block-1 line refs pin at abs=1e-4 against the worksheet (SAP 68,
cost 951.3425, CO2 4767.4862, space 16086.3557, main fuel 19150.4235,
HW 3307.2639, lighting 262.0885).
This is the third independent 1e-4 confirmation that the cascade
reproduces the spec engine for the 6035 archetype (after S0380.192
Simplified-RR + S0380.193 suspended-floor). It differs from 6035 in one
input only — the Main first-floor HLP (15.99 here vs 6035's 8.32) — so
6035's +19 PE vs the lodged register is lodged-register divergence, not
a calculator gap. A byte-identical 6035 replica (first-floor HLP 8.32)
would let 6035 itself be pinned directly to close that out.
2330 passed (+11), 0 failed; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RdSAP 10 §5 (PDF p.29) "Floor infiltration (suspended timber ground
floor only)", age band A-E, splits on whether a floor U-value is
supplied:
a) [U-value supplied] if floor U-value < 0.5 → "sealed", (12) = 0.1
b) [no U-value supplied] retro-fitted insulation → "sealed" 0.1;
otherwise "unsealed", (12) = 0.2
`_has_suspended_timber_floor_per_spec` fed the cascade's COMPUTED default
U into rule (a), so an as-built/uninsulated suspended-timber floor whose
default U happens to be < 0.5 was marked "sealed" (0.1) where Elmhurst
uses "unsealed" (0.2). That dropped (18) infiltration 0.85 → 0.75, (25)
effective ACH, HTC, and understated space heating ~450 kWh.
Fix: gate rule (a) on `floor_u_value_known` — a computed default U is not
a supplied value, so it falls through to (b). Verified against the
cert 001431 sim-case-2 worksheet: floor "As built", U=0.43 (matches the
worksheet's (28a) 0.4300 exactly), (12)=0.2 unsealed. Golden cert 6035
(also a suspended uninsulated floor) is unaffected — its U=0.63 ≥ 0.5
already routed to unsealed.
Promotes sim case 2 to the e2e harness as `001431_rr` (Main + Extension
+ Simplified room-in-roof — the 6035 archetype). All 11 Block-1 line
refs pin at abs=1e-4, locking BOTH this fix and S0380.192 (Simplified-RR
remaining area) end-to-end: SAP 69, cost 920.5046, CO2 4566.7090, space
15269.8593, main fuel 18178.4039. 2319 passed (+11), 0 failed; pyright
net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the user-simulated 001431 case (the cert that drove S0380.189/.190)
as an Elmhurst-only e2e fixture: Summary PDF → extractor → mapper →
calculator, every Block-1 SapResult field pinned against the
P960-0001-001431 worksheet at abs=1e-4. All 11 pins pass with zero
residual — the case is clean, confirming the S0380.190 gas-combi fuel
derivation closes the Summary path natively.
Verified the handover's flagged "+0.0007 SAP" was a target artifact, not
a cascade gap: the worksheet displays ECF (257) rounded to 1.6047 and
integer SAP (258)=78; the cascade's continuous SAP is computed from the
UNROUNDED ECF = (255)*(256)/((4)+45) = 660.9750*0.4200/173.0, giving
77.6147 — which matches the worksheet's own unrounded value. Pinning the
continuous SAP from the display-rounded ECF (→ 77.6144) was the wrong
target. Block-1 line refs all match exactly: (211) 10699.7225, (219)
3327.1592, (231) 86.0, (232) 283.2229, (255) 660.9750, (272) 3000.1664,
Σ(98) 8987.7669.
Summary mirrored into the tracked fixtures dir as
Summary_001431_gas_combi.pdf (distinct name — the corpus reuses cert
001431 across every heating variant); source Summary + worksheet tracked
under sap worksheets/golden fixture debugging/ as the pin ground truth.
2302 passed (+11), 0 failed; pyright net-zero on new/changed files.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The calculator tests lived under domain/sap10_calculator/{tests,worksheet/
tests,rdsap/tests,climate/tests,validation/tests}, none of which are in
pytest.ini testpaths — so CI (which collects tests/) never ran them. Relocate
all five dirs to tests/domain/sap10_calculator/{,worksheet,rdsap,climate,
validation}, mirroring the tests/domain/property_baseline/ convention, so the
cascade-pin / golden / e2e conformance suites run in CI.
Mechanics:
- git mv preserves history (110 files).
- Flattening the trailing /tests keeps each file's depth-to-repo-root
identical, so all 16 repo-root parents[4] fixture refs stay valid. Only
test_pcdb_etl.py's parents[1] (→ pcdb data) and one hardcoded absolute
golden-fixture path in test_cert_to_inputs.py needed rebasing.
- Cross-imports rewritten domain.sap10_calculator.worksheet.tests →
tests.domain.sap10_calculator.worksheet (21 files incl. the external
importer backend/documents_parser/tests/test_summary_pdf_mapper_chain.py).
- Golden-fixture path strings in test_summary_pdf_mapper_chain.py +
scripts/fetch_cohort2_api_jsons.py updated to the new location (the JSONs
moved with the rdsap tests).
load_cells / gitignored worksheet xlsx: the xlsx-pinned tests (test_dimensions
/ ventilation / water_heating) read 2026-05-19-17-18 RdSap10Worksheet.xlsx,
which is gitignored (.gitignore `*.xlsx`) and so absent in CI. _xlsx_loader.
load_cells now pytest.skip()s when the file is absent, so those tests run
locally and skip cleanly in CI instead of erroring — no new CI failures from
the move, and the gitignore policy is respected.
Verified: tests/domain/sap10_calculator + backend/documents_parser +
tests/domain/property_baseline = 2248 pass, 1 skipped; pyright resolves the
new import paths with zero import-resolution errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
