SAP 10.2 Appendix G4 (PDF p.72-73). A PV diverter routes surplus PV
generation (the would-be export EPV,m × (1 − βm)) to an immersion heater
in the hot-water cylinder. Per G4 step 4:
SPV,diverter,m = EPV,m × (1 − βm) × 0.8 × fPV,diverter,storageloss
(0.8 = cylinder heat-acceptance; fPV,diverter,storageloss = 0.9 for the
higher storage temperature), clamped to ≤ (62)m + (63a)m, and entered as
the negative worksheet (63b)m (step 5). The β factor is computed on the
PRE-diverter (219) per the §3a note (lines 5485-5486). Effects:
- (64)m = (62)m + (63b)m → less main-system water-heating fuel (219);
- export drops to EPV,ex,m = EPV,m(1 − βm) + (63b)m / 0.9 (§4 p.94
line 5501); the onsite dwelling portion EPV,m × βm is unchanged.
Inclusion (G4 step 1) requires ALL of: a PV system connected to the
dwelling; a cylinder larger than (43) average daily HW use; no solar
water heating; no battery — else the diverter is disregarded.
Three layers:
- extractor reads Summary §19 "Diverter present"; schema 21.0.0/21.0.1
SapEnergySource gains `pv_diverter` (API `sap_energy_source.pv_diverter`);
- `Renewables.pv_diverter_present` + domain `SapEnergySource.pv_diverter_present`,
set in both the Elmhurst and API mapper paths;
- `_pv_diverter_monthly_kwh` applies the G4 math after the β split;
`cert_to_inputs` recomputes (219) and the PV export.
On simulated case 19 (electric storage heaters, 7-hour, PV + diverter):
SAP continuous 50.33 → 51.34 (worksheet 51.2221; both round to the
lodged 51), cost (255) 1847.5 → 1812.3 (ws 1816.6), CO2 (272) 3331 →
3120 (ws 3126), with (233a) dwelling 1280.6 (ws 1280.4). The residual
+0.11 SAP is an upstream winter Appendix-M monthly-EPV-shape gap +
fabric (33) +1.0, tracked as the next case-19 cause. Suite: 2412 pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Appendix M1 §6 (PDF p.94, lines 5510-5513): "apply the normal
import electricity price to PV energy used within the dwelling and the
'electricity sold to grid, PV' price from Table 12 to the energy
exported. In the case of the former, use a weighted average of high and
low rates (Table 12a)."
`_pv_dwelling_import_price_gbp_per_kwh` was returning the bare off-peak
LOW rate (5.50 p/kWh on a 7-hour tariff) for the PV-used-in-dwelling
credit. PV self-consumption displaces the dwelling's "all other uses"
electricity (lighting / appliances / pumps), which on an off-peak tariff
bills at the Table 12a Grid 2 ALL_OTHER_USES weighted blend, not the low
rate. On simulated case 19 the worksheet (252)/(269) credits
PV-used-in-dwelling at 14.3110 p/kWh = 0.90 × 15.29 + 0.10 × 5.50; we
credited it at 5.50, under-crediting onsite PV by ~£0.088/kWh on every
off-peak PV cert.
Fix delegates to `_other_fuel_cost_gbp_per_kwh(tariff, prices)` (the same
ALL_OTHER_USES rate): STANDARD tariff still returns the flat Table 32
code 30 13.19 p/kWh (golden cohort unchanged — all 2412 tests pass);
off-peak returns the weighted high/low blend. Call sites now pass the
resolved `_rdsap_tariff(epc)`. The now-unused
`_off_peak_low_rate_gbp_per_kwh_via_meter_heuristic` (its only caller)
is removed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Appendix M1 §3a (PDF p.93, lines 5470-5476): "E_space,m =
(211)m + (213)m + (215)m, where (211), (213) and/or (215) should be
included only where the fuel code applied to them in Section 10a of the
SAP worksheet is 30, 32, 34, 35 or 38 (i.e. electricity not at the
low-rate)."
The PV-eligible demand D_PV,m was adding 100% of the main space-heating
fuel (211)m whenever the main's Table-12 code was in the eligible set
(30, …), ignoring the off-peak high/low split that §10a already bills
via `_space_heating_fuel_cost_gbp_per_kwh`. Electric STORAGE heaters on
a 7-hour tariff are charged wholly at the low rate (Table 12a Grid 1 SH
fraction 0.00; worksheet (240) high-rate cost = 0), so none of (211)
may enter D_PV — but the cascade counted it all, inflating R_PV,m =
E_PV,m / D_PV,m and therefore the β onsite-PV split in the heating
months.
Fix mirrors the cost-side rate split: `_main_space_heating_high_rate_
fraction(main, tariff)` returns the high-rate portion (1.0 for
non-electric / STANDARD, the published Grid 1 SH fraction otherwise,
0.0 when the Grid 1 SH row is unwired → 100% low rate), and
`_pv_eligible_demand_monthly_kwh` scales the (211)m contribution by it.
Backward-compatible: STANDARD-tariff electric mains and the gas-main /
electric-secondary PV cohort are unchanged (fraction 1.0).
On simulated case 19 (electric storage heaters, 7-hour, PV) this takes
β_Jan 0.894 → 0.792, matching the worksheet 0.791, and the summer months
(no main heating) already pinned exactly.
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>
RdSAP 10 §12 (PDF p.62) Dual-meter dispatch: "the choice between 7-hour
and 10-hour is made by the main heating type ... if the main system is a
direct-acting electric boiler (191), or electric room heaters ... it is
10-hour tariff." The electric room-heater codes — Table 4a 691 (panel/
convector/radiant), 692 (fan), 693 (portable), 694 (water-/oil-filled),
699 (assumed) — were missing from `_RULE_3_TEN_HOUR_CODES` (the long-
standing TODO there), so a Dual-meter room-heater cert fell through to
Rule 4 (7-hour default).
Compounded with S0380.230 (which routes room heaters to Table 12a
OTHER_DIRECT_ACTING_ELECTRIC): at 7-hour the high-rate fraction is 1.00
(all at 15.29 p), but at the correct 10-hour it is 0.50 split over the
10-hour rates (14.68 / 7.50 p) → blended ~11 p. Without this fix .230
over-charged and flipped the cluster from over- to under-rating.
1,000-cert 2026 API sample: cat-10 mean |err| 7.11 → 5.26, signed mean
+5.08 → -0.86 (now balanced, 22 over / 26 under — the systematic
directional bias is gone). Overall mean |err| 2.16 → 2.04. Full §4 suite
green (2406 passed).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Table 12a Grid 1 (PDF p.191): an electric room heater (RdSAP
main_heating_category 10, e.g. SAP code 691) is direct-acting electric,
so it sits on the "Other systems including direct-acting electric" row —
7-hour high-rate fraction 1.00, 10-hour 0.50. It runs on demand, mostly
at the HIGH rate; it does NOT earn the 100%-low-rate of overnight storage
charging (which is category 7).
`_table_12a_system_for_main` only mapped ASHP, so an electric room heater
fell through to the "100% low-rate" fallback (5.50 p, £0.0550), under-
charging space heating by ~9.79 p/kWh and systematically OVER-rating the
cluster. Now maps electric cat-10 mains to OTHER_DIRECT_ACTING_ELECTRIC
(gated on `_is_electric_main`, so gas/solid-fuel cat-10 room heaters are
excluded). The same Table 12a fraction flows through cost, CO2 (Table
12d) and PE (Table 12e) — all three callers already pre-gate on electric.
Mirror of S0380.228 (same fallback bug for electric SECONDARY heating).
1,000-cert 2026 API sample (no worksheet for this cluster — ±0.5-vs-lodged
fallback bar): cat-10 mean |err| 9.49 → 7.11, %<0.5 10.4% → 16.7%;
headline %<0.5 42.5% → 42.9%, overall mean |err| 2.29 → 2.16. cat-7
(storage) and cat-2 (gas) unchanged. Full §4 suite green (2405 passed).
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>
SAP 10.2 Table 3 (PDF p.160) row 1: primary circuit loss applies when
"hot water is heated by a heat generator (e.g. boiler) connected to a
hot water storage vessel via insulated or uninsulated pipes". The Table
4a hot-water-only codes (PDF p.166) 911 gas / 912 liquid / 913 solid
boiler-circulator + 921-931 range cooker with boiler are each a heat
generator feeding the cylinder through a primary loop.
`_primary_loss_applies` keyed only off the resolved DHW `main` — but for
these certs `_water_heating_main` returns the SPACE main (e.g. electric
storage heaters, SAP code 402, which has no primary loop), so every
boiler branch missed the gas water-boiler's primary circuit and (59)m
went to zero. New branch keys off `water_heating_code` ∈
`_WATER_HEATING_BOILER_CIRCULATOR_CODES`. 941 (electric HP for water
only) is excluded — HP DHW vessels follow the Table 3 integral-vessel
rules.
Simulated case 19 (electric storage main + WHS 911 + 210 L cylinder):
(62)m total HW demand 2493.30 → 3169.98 kWh/yr, matching the worksheet
(the missing 676.68 kWh/yr = the worksheet's (59) primary-loss annual
sum, h=5/p=0). The remaining (64)/(219) gap is the PV diverter (63b),
deferred to its own slice.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Table 12a Grid 1 (PDF p.191): secondary heating is a direct-
acting electric room heater (RdSAP 10 §A.2.2 default), on the "Other
systems including direct-acting electric" row — 7-hour high-rate fraction
1.00, 10-hour 0.50. A room heater runs on demand, mostly at the high
rate; it does NOT earn the 100%-low-rate of overnight storage charging.
`_secondary_fuel_cost_gbp_per_kwh` previously returned the flat off-peak
LOW rate (5.50 p, £0.0550) for every off-peak electric secondary, under-
charging by 9.79 p/kWh. New `_secondary_off_peak_rate_gbp_per_kwh` mirrors
`_space_heating_fuel_cost_gbp_per_kwh`: it blends the Table 12a high-rate
fraction (OTHER_DIRECT_ACTING_ELECTRIC) against the Table 32 high/low
rates, with the 18-/24-hour fallback to the low rate.
Simulated case 19 (electric storage main + electric secondary, Dual/7-hour
meter) is the worksheet case (242): "Space heating - secondary
(1.00*15.29 + 0.00*5.50)" → 15.29 p/kWh = £0.1529. This was the primary
cat-7-cluster cost driver: total cost 1485.68 → 1835.53 (worksheet
1816.58), SAP cont 60.11 → 50.67 (worksheet ~51.22). Remaining +19 cost
is HW/space-heating kWh (next slices).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Table 2b note b (PDF p.159) applies the ×0.9 temperature-factor
reduction only when DHW is "separately timed" relative to space heating
on a SHARED heat generator ("boiler systems, warm air systems and heat
pump systems"). Per RdSAP 10 §10.5.1 (PDF p.55) a separate boiler/
circulator providing DHW only (water-heating code 911 = "Gas boiler/
circulator for water heating only") is NOT the main space-heating system
— so there is no shared timer to apply the ×0.9 against. `_separately_
timed_dhw` now returns False when water_heating_code is not "from main /
2nd-main system" ({901,902,914}), mirroring the existing WHC 903 electric-
immersion carve-out.
Simulated case 19 (electric storage main SAP 402 + WHS 911 + 210 L
loose-jacket cylinder) is the worksheet case. The single flag drives both:
- (53) Temperature factor: 0.54 → 0.6000 (worksheet base, no ×0.9)
- (55) storage loss/day: → 3.4531; (56)/(57)m Jan → 107.0456 (1e-4)
- (59)m primary loss: h=3 (43.31) → h=5 (Jan 64.5792), worksheet-exact
This also worksheet-pins S0380.224's loose-jacket storage loss magnitude
at 1e-4, previously only direction-validated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The §10.7 no-water-heating default cylinder raised UnmappedSapCode for
age bands A-F (2 certs in a 2026 sample, bands B + C) because Table 29's
"A to F: 12 mm loose jacket" row wasn't plumbed — the loose-jacket
storage-loss branch didn't exist. S0380.224 added it, so this slice
completes the Table 29 lookup.
Restructure _TABLE_29_DEFAULT_CYLINDER_INSULATION_BY_AGE to carry
(cylinder_insulation_type, thickness_mm) per band — A-F → (loose jacket,
12), G/H → (factory, 25), I-M → (factory, 38) per RdSAP 10 Table 29
(PDF p.56) — and have the default read both, setting the loose-jacket
type for A-F instead of hardcoding factory. The strict-raise is retained
only for an absent / out-of-A-M age band (no Table 29 row).
Validated: certs 2211 (band B, SAP 49.8 vs lodged 52) and 3420 (band C,
11.2 vs 11) now compute. §4 + golden suite 2395 passed — the corpus
"no system" cert (age G, 25 mm factory) is unchanged. cert_to_inputs.py
pyright unchanged at 32; new test suppresses reportPrivateUsage.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`_cylinder_storage_loss_override` returned None for any cylinder whose
cylinder_insulation_type wasn't 1 (factory), so a loose-jacket cylinder
(code 2, RdSAP 10 field 7-11) fell to the cascade's zero-storage-loss
combi/instantaneous default — its real storage loss vanished. SAP 10.2
Table 2 Note 1 gives loose jacket a SEPARATE, ~2× higher loss factor
(L = 0.005 + 1.76/(t+12.8) vs factory 0.005 + 0.55/(t+4)); the
cylinder_storage_loss_factor_table_2 helper already implements it — only
the dispatch was missing.
Fix: a `_cylinder_storage_loss_insulation_label` resolver maps the lodged
code to the Table 2 branch (1 → factory_insulated, 2 → loose_jacket;
None/0/unknown → None, keeping the conservative no-loss default). The
override and the HW storage call now route through it instead of
hardcoding "factory_insulated".
Evidence + validation: a random 2026 register sample has 22 loose-jacket
certs that over-predicted SAP by +2.29 mean (18/22 too high, 1/22 within
0.5) — the exact signature of under-counted HW storage loss. After the
fix their mean error collapses to +0.45 and 11/22 land within 0.5, with
ZERO regression across the worksheet-validated cohort (§4 + golden suite
2394 passed — no validated cert lodges loose jacket, so none shifts).
Also unblocks the §10.7 A-F no-water-heating default (next slice) which
needs the loose-jacket branch. cert_to_inputs.py pyright unchanged at 32.
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>
Two certs fetched fresh from the GOV.UK EPB register, each with an
Elmhurst Summary PDF (input) and a dr87 worksheet PDF (the (1)..(286)
ground truth):
0340-2467-9260-2006-6521 (Summary_000922 / dr87-0001-000922)
5500-5070-0822-0201-3663 (Summary_000920 / dr87-0001-000920)
Both run through BOTH front-ends — from_api_response and
from_elmhurst_site_notes — and through the rating + demand cascades.
Cross-mapper parity holds: the two paths agree to <1e-4 on continuous
SAP, fuel cost, CO2 and PE. Both paths reproduce the worksheet exactly:
0340: (255) cost 776.4295, (272) CO2 2875.0498, (286) PE 16474.5616;
fabric (33) 171.6188, (37) 205.9358; SAP int 70 = lodged.
5500: (255) cost 751.8295, (272) CO2 2423.4547, (286) PE 14397.0118;
fabric (33) 141.1226, (37) 167.3696; SAP int 66 = lodged.
Pinned in two tables of test_golden_fixtures.py:
- _EXPECTATIONS / test_golden_cert_residual_matches_pin — SAP/PE/CO2
residual vs the integer-rounded lodged register (SAP resid +0 both).
- _WORKSHEET_PE_CO2 / test_golden_cert_pe_co2_matches_worksheet —
PE (286)/(4) and CO2 (272) vs the worksheet at +0.0000 (the
load-bearing 1e-4 check; lodged register is integer-rounded).
Dropped-field audit (raw JSON keys vs the schema-21.0.1 dataclass
fields consumed by from_dict) re-run on both fresh JSONs: no new
silently-dropped fields — only created_at metadata and the
shower_outlet_type/shower_wwhrs keys already handled by
_normalize_shower_outlets (mapper.py:2047). No calculator or mapper
change required; this is pure validation + regression-pinning.
Full §4 suite: 2392 passed, 1 skipped.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Updated 2130's pin notes with the case-18 finding: our cascade reproduces
the worksheet PV split to the decimal (gen 2684.17 / onsite 970.77 / export
1713.40), so the Appendix M1 β-split is exact, not the suspected bug. With
the gas PE factor also exact (1.13) and the wall measurement now wired
(S0380.215), 2130's +2/-11.72 is the irreducible API-only lodged residual
(0240-like), not a closable calculator bug. Notes-only; pin unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The schema-21 SapBuildingPart never declared `wall_insulation_thickness_
measured`, so `from_dict` silently discarded it. When a cert lodges
`wall_insulation_thickness == "measured"` the actual value (mm) lives in
that dropped field, so the cascade fell back to the 50 mm "insulation
present, unknown thickness" default instead of the lodged measurement.
Cert 2130 Ext1 lodges solid brick band B + INTERNAL insulation
"measured"/100 mm. Per RdSAP 10 §5.7 Table 8 (insulated-wall U by age band
+ insulation thickness) the 100 mm row gives U=0.32; the unknown-thickness
fallback gave 0.55. New `_api_resolve_wall_insulation_thickness` substitutes
the measured value for the "measured" sentinel; the existing
`_insulation_bucket`/Table-8 path then computes the correct U. Field added
to schema 21.0.0/21.0.1 SapBuildingPart; domain field widened to
Union[str, int] to match `roof_insulation_thickness`. Isolated: 2130 Ext1
is the only bp lodging "measured" across all 47 fixtures.
This spec-correct fix EXPOSED an offsetting under-count it had been masking
(per the repo's no-special-handling rule — the pre-fix +1 was two bugs
cancelling): 2130 cont SAP 83.35 → 83.78 (resid +1 → +2), PE -7.56 →
-11.72, CO2 -0.045 → -0.095. The exposed -11.72 PE (~-746 kWh/yr) is the
deferred gas-combi-PE + PV-β-credit under-count from S0380.45/.49, now
un-masked — the next slice. Re-pinned 2130 with the cause documented.
Suite: 2391 passed, 1 skipped. Zero new pyright errors (mapper 32=32).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
After three faithful-worksheet iterations (simulated cases 15/16/17), the
7536 +1 SAP residual is confirmed 0240-like — an Elmhurst register-rounding
residual not reproducible from the API-only JSON, not a calculator bug.
Case 17 is faithful on windows (Main 16.98 / Ext1 13.59 / Ext2 1.89) and
ground floors; every per-element value matches our cascade: walls
0.70/0.28/0.40, roofs 0.40/0.18/0.68 (S0380.214), window U-eff
2.4368/1.8519, ground floors 0.97/0.26/1.12. The only worksheet divergences
were manual-entry artifacts: case-16 inverted the floor order (put the
50.98 m² upper floor as ground), and case-17 auto-derived spurious "to
external air" exposed floors from the small-ground/big-upper geometry —
real 7536 lodges floor_heat_loss 2/7/3 (unheated-space / ground), none is
code 1 (exposed). Our spec-correct cont SAP is 68.924; lodged 68 carries
Elmhurst's own residual.
Notes-only; pin unchanged (resid +1, PE -6.1952, CO2 -0.1639). Suite green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A "Pitched, sloping ceiling" roof (roof_construction code 8) lodged with
"As Built" insulation (no measured thickness → None) was wrongly routed to
RdSAP 10 Table 18 column (1) "insulation between joists or unknown". A
sloping ceiling has no joist void, so per RdSAP 10 §5.11 roof-input item
5-5 ("Sloping ceiling insulation … unknown / as built → Table 18") and
Table 18 note (b) ("Applies also to roof with sloping ceiling") it takes
column (3) — band F = 0.68, band L = 0.18 (vs col 1 0.40 / 0.16).
Discriminator is the code-8 "sloping ceiling" string only: code-5 vaulted
ceilings stay on column (1) per the 33 cohort-2 "ND" vaulted certs
(S0380.211), and the "NI"/"ND" unknown case is untouched. New
`is_pitched_sloping_ceiling` flag threaded from heat_transmission to
`u_roof`; pre-1950 bands already reach the same col (3) value (2.30) via
the mapper's thickness=0 → Table 16 row-0 override, so the new branch
carries the post-1950 bands where col 1 ≠ col 3.
Worksheet-validated by simulated case 15 (the 7536 replica): our cascade
on its Summary matches the P960 worksheet exactly — roof HLC 29.17 W/K,
cont SAP 65.04 vs 65. Re-pins golden cert 7536: roof 26.77 → 29.17, cont
SAP 69.071 → 68.924, PE -7.0776 → -6.1952, CO2 -0.1875 → -0.1639 (SAP
integer 68, resid +1 unchanged — the remaining +0.92 is a diffuse demand
under-count needing a fully-faithful worksheet). Blast radius: 7536 only.
Suite: 2388 passed, 1 skipped (main); sap10_ml 233 passed + 2 pre-existing
stone-formula failures (out of scope). Zero new pyright errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Cert 9390 (community mains-gas boiler, API main_fuel_type=20) drew £0
standing charge → fuel cost under-counted → SAP read +4 high (71 vs 67).
Root cause: the standing-charge logic (`additional_standing_charges_gbp`)
only knows the GAS branch (`_is_gas_code`) and the off-peak-electric branch.
A heat-network community fuel is not a Table-32 gas code — EPC 20 = "mains
gas (community)" normalises to Table-32 code 20 (biomass), so
`_is_gas_code(20)` is False and the standing came out £0. The Summary path
masks this because it lodges community gas as Table-32 code 1 (ordinary
mains gas), which IS gas-recognised and already draws the £120 gas standing
— so the CH1-6 corpus was unaffected while the API path lost the charge.
Spec basis (verified against SAP 10.2 spec PDF):
- Table 12 (p.191) "Heat networks" row standing charge = £120/yr, note (k).
- Note (l): "Include half this value if only DHW is provided by a heat
network."
- §C3.2 (p.58): the full charge applies when the space heating is also a
heat network.
Worksheet-validated: simulated case 14 (community boilers + mains gas,
space + water) → worksheet (351) Additional standing charges = £120.
Fix: new `_heat_network_standing_charge_gbp(epc, main)` returns the
heat-network standing (£120 full when the space main is a heat network;
£60 when only DHW is on the network) or None otherwise. Applied at both
fuel-cost call sites, REPLACING the fuel-based `additional_standing_charges
_gbp` for heat-network mains (NOT additive) so a Summary-path community-gas
main — already £120 via the gas branch — is not double-counted to £240. The
CH1-6 community corpus stays exactly £120 (59 corpus tests pass).
9390 SAP +4 → -2 (cont 65.39 vs lodged 67): the spec-correct £120 standing
EXPOSES a separate ~7% demand over-count (also visible as PE 220 vs lodged
205) — a heat-source-efficiency-default / fabric residual, follow-up scope.
9390 is unpinned (retired P2.2 per ADR-0010 §10); helper locked by 2 unit
tests. Full suite 2386 passed, 1 skipped.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Cert 9390-2722-3520 (community mains-gas boiler scheme, sap_main_heating_
code=301, main_fuel_type=20) emitted CO2 0.44 t vs lodged 2.8 t — 6.4x low.
Root cause: the EPC `main_fuel_type` enum and the SAP Table 12 / Table 32
fuel-code numbering COLLIDE in the 18-25 range. Per
`datatypes/epc/domain/epc_codes.csv` (RdSAP-Schema-17.0) EPC fuel
20 = "mains gas (community)", but Table 12/32 code 20 is a solid biomass
fuel (CO2 0.028, PE 1.046, wood-logs price). The factor lookups
(`co2_factor_kg_per_kwh` / `primary_energy_factor` / `unit_price_p_per_kwh`)
check the Table-12/32 dict FIRST, so the EPC community fuel 20 silently
returned the biomass factor instead of translating 20 -> Table 12 code 51
(community mains gas: CO2 0.210, PE 1.130, mains-gas price).
Fix: new `_heat_network_factor_fuel_code(main)` translates the EPC community
fuel to its Table-12 code via `API_FUEL_TO_TABLE_12`, but ONLY for
heat-network mains (`_is_heat_network_main`) — a genuine biomass boiler
(non-community) keeps its raw Table-12 factor. Applied at the five
heat-network factor sites: space-heating CO2 / PE / unit-price and
water-heating (WHC 901) CO2 / PE. The Summary path is unaffected (it maps
"Mains gas - community" to code 1, no collision), so the community-heating
corpus (CH1-6) is untouched.
Worksheet-validated against simulated case 14 (community boilers + mains
gas, SAP code 301): worksheet (367) CO2 factor 0.2100, (467) PE factor
1.1300 — exactly the Table-12 code-51 values the translator now reaches.
9390 CO2 0.44 -> 3.03 t (lodged 2.8; spec-correct factors over the API-only
register residual per [[feedback-worksheet-not-api-reference]]), PE 204 ->
220 (the spec-correct 1.13 factor; the prior 204≈205 match was the
collision coinciding with the register residual). 9390 is unpinned (retired
at P2.2 per ADR-0010 §10); the translator is locked by two unit tests.
REMAINING (separate follow-up): 9390 SAP +4 is a cost-side gap — the
heat-network cost path does not apply the 1/heat_source_eff (1/0.80)
scaling that the CO2/PE paths do, so community fuel cost under-counts.
Suite: 2616 passed, 1 skipped (community corpus green); the 2
test_rdsap_uvalues stone-formula failures are pre-existing (HEAD 58ff7d88).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Closes the Ext1 vaulted-roof over-count that S0380.209 exposed on golden
cert 0240-0200-5706. BP2 lodges roof_construction=5 (vaulted ceiling),
roof_insulation_thickness="NI" (parsed to 0), description "Pitched,
insulated (assumed)", band J. The cascade returned U=0.68 — the RdSAP 10
§5.11.4 (p.44) retrofit-50 mm "insulation at joists" row. A vaulted /
sloping ceiling has no ceiling-joist void, so that row does not apply; per
RdSAP 10 §5.11 Table 18 (p.45) it takes the column (1) age-band default
(band J = 0.16).
The arbiter is the cohort, not the spec text alone: 33 cohort-2 certs
lodge "ND" (thickness None) vaulted roofs (roof_construction=5, band D)
that already pin to their dr87 worksheets at U=0.40 = Table 18 col (1) by
falling through the age-band default. 0240's only difference is the "NI"
sentinel (insulation present, unknown thickness) which uniquely hit the
0.68 override. (The S0380.209 note's predicted "cont ≈ 72.31" assumed a
col-3 0.25 value; the cohort's ND vaulted roofs disprove that — they use
col (1), so 0240 lands at cont 72.4617.)
Implementation: new `u_roof(is_sloping_ceiling=...)` flag, threaded from
heat_transmission for roof_construction_type containing "sloping ceiling"
(code 8) or "vaulted" (code 5). It fires only for the NI case
(thickness 0 + "insulated (assumed)"), routing to the col (1) age-band
default; the "ND"/None path is untouched (already col 1) and a NORMAL
pitched-with-loft roof still takes the §5.11.4 50 mm row (flag defaults
False). roof 76.93 → ~68 W/K → 0240 PE +5.5044 → +1.5181, CO2 +0.2757 →
+0.0728 (SAP integer 72 unchanged — the true value; lodged 73 needs the
unpreserved 2013+ pump).
Also corrects test_u_wall_cavity_as_built_partial_insulation_routes_to_
filled_cavity_row → ..._routes_to_as_built_row: a missed S0380.210
follow-up. That test (in domain/sap10_ml/tests/, which the AGENT_GUIDE §4
suite command does not run) asserted the pre-S0380.210 "partial insulation
→ filled" behavior on legacy-map parity, not worksheet evidence; S0380.210
corrected it to the as-built row per RdSAP 10 Table 6 + golden cert 0390's
four-metric closure.
Suite: 2614 passed, 1 skipped; the 2 remaining failures in
test_rdsap_uvalues.py (stone §5.6 thin-wall formula vs Table-6 1.7 cap)
are pre-existing (fail at HEAD 58ff7d88, before this branch's work).
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>
Cert 0240's SAP residual (-1) and a chunk of its PE/CO2 was an API-mapper
bug: it flattened ALL windows into sap_windows, so the 6 windows lodged
with window_wall_type=4 — the RdSAP code for a roof window ("Roof of Room"
rooflight / inclined glazing) — were billed as vertical wall glazing on
worksheet (27) at U=2.0, instead of roof windows on (27a) at the Table 6e
Note 2 inclination-adjusted U (DG 2002+ vertical 2.0 + 0.30 = 2.30) with
45°-inclined solar gains.
window_wall_type=4 is the discriminator, NOT window_type=2 (certs 0390 /
7536 lodge window_type=2 on ordinary main-wall windows). Fix: partition
the 21.0.1 API window list into sap_windows (wall_type≠4) + sap_roof_
windows (wall_type=4); `_api_sap_roof_window` mirrors the site-notes
`_map_elmhurst_roof_window` (vertical U from the glazing Table-24 lookup +
0.30 inclination; 45° pitch; g/FF from the same lookup).
Validated against the simulated-case-6 worksheet, which bills these
identical windows on (27a) at U_eff 2.1062 (= 2.30 with the §3.2 R=0.04
curtain transform). The inclined solar gain dominates the higher U-loss,
RAISING the SAP:
- 0240: SAP cont 72.14 → 72.55 (resid -1 → +0 EXACT), PE +3.91 → +1.95,
CO2 +0.22 → +0.12
- 6035: 2 wall_type=4 rooflights — SAP still +0 exact, PE +1.84 → +1.37,
CO2 +0.01 → -0.0004
Blast radius is exactly these two certs (only golden fixtures with
wall_type=4). Suite: 2354 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>
Golden cert 6035's residual (SAP -2 / PE +19.16 / CO2 +0.42t) was a real
API-mapper bug, NOT lodged divergence (prior claim retracted).
The API `room_in_roof_type_1` block lodges gable walls by length only (no
height). The mapper carried just the scalar `gable_*_length_m`, and the
cascade's `_part_geometry` gable formula silently drops height-less gables
(needs a height) -> the whole A_RR shell `12.5√(A_RR_floor/1.5)` billed as
roof at U_RR=2.30 instead of the §3.9.1(e) residual
`A_RR − Σ gables`. On 6035 that over-counted roof by 22.78 m² × 2.30 =
+52.4 W/K (roof 130.73 -> 78.33, matching the site-notes case-4 replica at
1e-4 — cross-mapper parity).
RdSAP 10 §3.9.1(e) (PDF p.21): "the area of the room-in-roof gable walls
... is deducted from A_RR to give the residual roof area." Fix: route the
Type 1 gables through `detailed_surfaces` (gable area = L × the §3.9.1
default RR storey height 2.45 m; gable_wall_type 0=Party->gable_wall U=0.25,
1=Exposed->gable_wall_external "as common wall" per Table 4 p.22) so the
cascade's Detailed-RR residual fires — the same path the site-notes mapper
already uses.
Re-pinned golden residuals:
- 6035: SAP -2 -> +0 (exact), PE +19.16 -> +1.84, CO2 +0.42 -> +0.01
- 0240: same fix applies (2 Party gables L=6.4); PE +5.80 -> +3.91,
CO2 +0.32 -> +0.22, SAP integer unchanged
Also corrected the stale "gable_wall_type 0 = external" schema comment
(6035's Summary proves 0=Party, 1=Exposed) and added a strict
UnmappedApiCode raise for unknown gable_wall_type codes.
Suite: 2342 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>
A Simplified room-in-roof (RdSAP 10 §3.9.1, PDF p.21) does NOT measure
its slope / flat-ceiling / stud-wall surfaces — the Elmhurst Summary
lodges placeholder Length/Height cells (a 40 m flat-ceiling height, a
32 m slope on a 4.65 m-wide gable). The spec instead derives one
timber-framed "remaining area" from the floor area:
A_RR = 12.5 × √(A_RR_floor / 1.5) §3.9.1(d)
A_RR_final = A_RR − ΣA_RR_gable/other §3.9.1(e)
The cascade already computes A_RR_final itself (heat_transmission.py:
`12.5 × √(A_RR_floor/1.5) − rr_walls_in_a_rr_area` residual), but only
when `detailed_surfaces` carries no roof-going kind (`has_roof_lodgement`
gate). `_map_elmhurst_rir_surface` emitted the placeholder slope/ceiling
rows as raw L×H for every assessment type, flipping that gate and billing
1024 m² + 160 m² of explicit roof area — a 7.5× fabric-heat-loss
explosion (cert 001431 sim case 2: SAP −14.6 vs worksheet 69, space
heating 114 378 vs ~15 000 kWh).
Fix: for a Simplified assessment, drop the roof-going surfaces in the
mapper so the cascade's residual formula fires. This matches how the API
path already (correctly) handles the same Simplified RR — scalar gable
fields, no roof-going detailed_surfaces (golden cert 6035) — and the
gables-only cert 000565. Detailed (§3.10) assessments still measure these
surfaces and keep them.
With the fix, sim case 2 total external area = 232.94 (worksheet exact),
roof 78.33 (was 2725.89), SAP 69.29 → worksheet integer 69. A small
residual (~450 kWh main fuel) remains — a separate fabric gap to walk
next. 2308 passed (+2), 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 newer Elmhurst Summary export lodges a gas combi as §14.0 "Fuel Type"
empty + "Main Heating SAP Code" 104 (EES "BGW"), with no fuel string. The
site-notes mapper left `main_fuel_type=''`, so `cert_to_inputs` raised
`MissingMainFuelType` — blocking the whole gas-combi Summary path
(reproduced on the simulated 001431 case).
SAP 10.2 Table 4b (PDF p.168) rows 101-119 are "Gas boilers (including
mains gas, LPG and biogas)": the code fixes the boiler type/efficiency but
NOT the carrier, so 104 alone can't distinguish mains gas from LPG. The
disambiguator is §15.0 "Water Heating Fuel Type" — a combi/boiler heats
space + water from one appliance — exactly mirroring the existing
liquid-fuel (codes 120-141) fallback. `_elmhurst_gas_boiler_main_fuel`
adopts the §15.0 carrier only when the SAP code is in 101-119 AND §15.0
resolves to a gas/LPG fuel, so a regular boiler + electric immersion
(§15.0 = "Electricity") still strict-raises rather than mis-billing gas
as electric.
2291 passed (+1), 0 failed; pyright net-zero on both files.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The §7 mean-internal-temperature cascade hardcoded the thermal mass parameter
(TMP) to 250 kJ/m²K at all 5 call sites, ignoring construction. RdSAP 10
§5.16 Table 22 (PDF p.48) makes TMP construction-dependent:
100 kJ/m²K — timber frame, cob, park home (regardless of internal
insulation); OR masonry (stone/solid brick/cavity/system
built) WITH internal insulation.
250 kJ/m²K — masonry WITHOUT internal insulation.
A too-high TMP inflates the §7 time constant τ = Cm/(3.6·H) (e.g. 40 h vs
16 h), under-cuts the temperature reduction between heating periods, and
over-states mean internal temperature → over-states space heating.
`_thermal_mass_parameter_kj_per_m2_k(epc)` classifies the MAIN building's
wall via the RdSAP `wall_construction` codes (5/7/8 = timber/cob/park) and
`wall_insulation_type` codes (3/7 = internal); unknown/curtain fall back to
the masonry 250 (no regression on unlisted classes). 17-case parametrised
test covers every Table 22 branch.
Diagnosis (per-line walk vs the user-simulated 001431 worksheet, same
archetype as golden cert 6035): fabric (26-37), internal gains (73), climate
(96)m and HTC (39) all EXACT; the entire +8.78 PE / -1.76 SAP gap was §7 MIT
(92) +0.71 °C, traced to TMP 250 vs Table 22's 100 (solid brick WITH internal
insulation). Fix closes the simulated case to 1e-4 on PE and CO2.
Blast radius: only golden cert 6035 re-pins (solid brick + internal
insulation) — SAP resid -6 → -2, PE +46.42 → +19.16, CO2 +1.07 → +0.42. The
47 dr87 cohort, 6 U985 fixtures and 41-variant heating corpus are all
masonry-no-internal → TMP unchanged at 250, all still pass. 2290 pass
(+17 new), 0 fail; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Appendix M1 §3a (p.93) defines PV-eligible demand as
D_PV,m = E_L,m + E_A,m + E_cook,m + E_ES,m + (231)·n_m/365 + E_space,m + E_water,m
where E_L,m is the lighting ELECTRICITY (Appendix L eq L10, = line (232)).
The cascade fed `internal_gains_result.lighting_monthly_w` — the L12 internal
heat GAIN G_L,m = E_L,m × 0.85 ("assuming 15%" of lighting energy does not
become internal heat) — into D_PV, understating it by 15% of lighting on
every PV cert. That depressed the monthly β onsite/export split and
under-credited PV primary energy uniformly across the year.
Same gain-vs-electricity class as the cooking fix S0380.73 (L18 gain vs L20
electricity). Fix: scale the (shape-identical) lighting gain profile to the
annual E_L `lighting_kwh_per_yr` (= (232)), mirroring the (219)m hot-water
scale-to-annual. Magnitude-only, so the shape-weighted lighting CO2/PE
effective factor (Σkwh×f/Σkwh, magnitude-invariant) is unchanged; appliances
need no scaling (G_A = E_A, no 0.85). Diagnosis was empirical first (calc
lighting D_PV 95.1 vs worksheet (232) 111.88, ratio exactly 0.85) then
confirmed against the spec text (L9d/L10/L12, M1 §3a).
Impact (calc − full-precision dr87 worksheet): ALL 47 worksheet certs now
match at <1e-4 on BOTH PE (max |Δ| 0.0000 kWh/m²) and CO2 (max |Δ| 0.0000 kg)
— the convergence target, met cohort-wide. Combined with S0380.187 this
closes the entire gas+PV + ASHP PV residual. Re-pinned 47 worksheet residuals
to 0.0000 and 31 drifted lodged residuals (PV certs). SAP integers unchanged;
chain SAP 1e-4 intact (164 pass). 2273 pass, 0 regressions; pyright net-zero.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The PV onsite/export β-split (SAP 10.2 Appendix M1 §3a, p.93) divides PV
generation by the monthly PV-eligible electricity demand D_PV,m. The cascade
included main and water electricity (when those fuels are electric) but had
no term for SECONDARY space heating. For the 10 cohort-2 gas-main +
electric-secondary + PV certs, the (215)m secondary electric fuel was dropped
from D_PV,m — understating demand in the heating months only, depressing the
monthly β, and under-crediting onsite PV primary energy.
Spec: Appendix M1 §3a counts E_space,m as the dwelling's TOTAL electric
space-heating demand; for a gas-main/electric-secondary dwelling that is the
secondary fuel. Diagnosis was decisive: E_PV (generation) matched the
worksheet exactly every month, the onsite (233a) split diverged ONLY in
heating months (Jun-Sep near-exact), and all 10 affected certs have PV while
all clean gas certs have none. Empirically adding (215)m to D_PV closed cert
3136 onsite 726.9 → 790.3 (worksheet 792.1).
Impact (calc − full-precision dr87 worksheet), the 10 certs:
PE +0.5..+1.5 → +0.02..+0.046 kWh/m²; CO2 −0.5..−1.1 → +0.002..+0.0095 kg.
The whole 47-cert cohort now matches at PE <0.05 / CO2 <0.025. SAP integers
unchanged; chain SAP 1e-4 pins intact (164 pass). The uniform ~0.03 PE remnant
on PV certs is the separate (233a)/(233b) summer-month D_PV discrepancy.
Re-pinned the 10 worksheet + 9 lodged golden residuals (improvements).
2273 pass, 0 regressions; pyright net-zero (file's 32 errors pre-existing).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The existing golden test compares calc PE/CO2 against the integer-rounded
lodged register values (energy_consumption_current / co2_emissions_current),
which conflates real calculator gaps with register rounding. This adds a
parallel pin against each cert's Elmhurst dr87 worksheet (286)/(272) at full
precision — a clean calculator-vs-Elmhurst signal for the 47 worksheet-backed
certs (9 ASHP + 38 cohort-2).
Findings at capture (calc − worksheet, on the worksheet's own decimal TFA):
- 37/47 exact on both PE (<0.05 kWh/m²) and CO2 (<0.02 kg).
- 10 higher-consumption gas certs carry PE +0.5..+1.5 kWh/m² AND
CO2 -0.5..-1.1 kg simultaneously. PE-over + CO2-under on the same
certs is the fingerprint of a small gas→electricity fuel-split
difference (elec PE 1.51 > gas 1.13, but elec CO2 0.136 < gas 0.21),
not a factor-value error — next slice candidate.
An earlier "41/47 PE gaps" reading was a JSON-integer-TFA division artifact;
comparing on the worksheet's decimal TFA (which the calculator also uses)
collapses it to the real 10. Worksheet values frozen as literals (the dr87
PDFs are untracked, so not parsed at test time) per the worksheet_unrounded_sap
convention. Also replaced a pre-existing pytest.approx with abs-diff to keep
the file at zero pyright errors (feedback_abs_diff_over_pytest_approx).
106 passed (was 59); pyright 0 errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 worksheet block 12b/13b (367)/(467) for a community heating
electric heat pump (Table 4a code 304 → Table 12 fuel 41 "heat from
electric heat pump"). The HP meters grid electricity, so per Table 12
note (s)/(t) + block 12b/13b footnote (a) its emission/PE factor is the
MONTHLY Table 12d/12e cascade (fuel 41 = standard-electricity profile),
weighted by the network heat profile, then × 1/heat-source-eff (1/COP):
(367)/(467) = [(307)+(310)] / COP × Σ((307+310)_m × factor_m)/Σ(...)
Per-line walk of CH3 (the displayed (367) 0.1535 / (467) 1.5717 are PDF
artifacts; the (373)/(473) totals reconcile only with):
CO2 factor = 0.15040 (monthly Table 12d wtd) vs cascade annual 0.136
PE factor = 1.55692 (monthly Table 12e wtd) vs cascade annual 1.501
Pre-slice the cascade routed code 304 through the non-electric branch
(`_co2_factor_kg_per_kwh(main) × 1/COP` = annual × scaling). New
`_is_heat_network_electric_main` (heat-network main whose fuel has a
Table 12d monthly set — i.e. fuel 41) routes all four factor helpers
(main + HW, CO2 + PE) through the monthly cascade × 1/COP. Non-electric
heat networks (gas 51 / oil 53 / coal 54) have no monthly set → annual
path unchanged (CH1, CH6 untouched).
Closure (CH3 was already SAP+cost EXACT):
CH3 (HP/Elec) CO2 −75.32→+0.0000 (= [(307+310)/3]×(0.1504−0.136)),
PE −249.32→−0.0000 (× (1.5569−1.501)) — FULLY EXACT
Corpus now 40/41 EXACT on all four metrics. Only CH6 remains: its
worksheet lodges a manual DLF=1.0 ("two adjoining dwellings") absent
from the Summary PDF (byte-identical to CH4 bar fuel type) — an
architectural limit, not a cascade gap. 2226 pass + 1 skip + 0 fail
(tolerances 1e-4 all metrics); pyright net-zero 43→43.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 worksheet block 12b (CO2) / 13b (PE) for community heating
"CHP and boilers" (SAP code 302). Per unit of network heat fuel
H = (307)+(310) the effective generation factor is:
chp×100/(362)×f_fuel − chp×(361)/(362)×f_disp + (1−chp)×100/(367)×f_fuel
(363)/(463) CHP fuel = chp_frac × 100/heat_eff × f_fuel
(364)/(464) less credit = −chp_frac × elec_eff/heat_eff × f_disp
(368)/(468) boiler fuel = (1−chp_frac) × 100/boiler_eff × f_fuel
f_fuel = Table 12 heat-network fuel factor (the CHP unit and the back-up
boilers burn the same community fuel — verified vs CH2 gas / CH4 oil /
CH6 coal worksheets (363)/(368)); f_disp = Table 12f (PDF p.196) credit
for the CHP-generated electricity. RdSAP 10 §C (p.58) defaults: heat eff
50% (362), electrical eff 25% (361), boiler eff 80% (367); CHP heat frac
0.35 per-cert via community_heating_chp_fraction.
New `_heat_network_code_302_effective_factor` + Table 12f flexible
constants (0.420 CO2 / 2.369 PE) + RdSAP §C efficiency constants, wired
into all four factor helpers (main + HW, CO2 + PE) ahead of the existing
single-fuel / 1-over-heat-source-eff path. The worksheet (368)/(468)
boiler emissions DISPLAY rounded/mis-aligned in the PDF, but the
(373)/(473)/(386)/(486) totals reconcile only with the boiler at the
full Table 12 factor — verified EXACT.
Two spec citations applied:
- Table 12f flexible-operation default for RdSAP community CHP is an
Elmhurst engine choice (Table 12f notes make "standard" the default);
mirrored per [[feedback-software-no-special-handling]] and documented
in SAP_CALCULATOR.md §8.3.
- Table 12 heat-network oil/biodiesel CO2 (codes 53/56) corrected
0.298 → 0.335 per Table 12 (p.189) "assumes 'gas oil'"; the code-302
oil cascade (CH4) was the first to exercise it. PE 1.180 was already
correct. No other variant uses these codes (no regression).
Closures (CO2 + PE only — the CHP credit does not touch cost/SAP):
CH2 (CHP/Gas) CO2 −1411.49→+0.0000, PE +1331.23→+0.0000 EXACT
CH4 (CHP/Oil) CO2 −4378.24→−0.0000, PE +319.81→−0.0000 EXACT
CH6 (CHP/Coal) CO2/PE re-pinned (+2411.54 / +5023.48) — its worksheet
lodges a manual DLF=1.0 the Summary doesn't carry, so
cascade DLF=1.45 over-scales H; same root as the CH6
SAP −7.49 / cost +£172 (separate DLF front).
CH2/CH4 are now CO2+PE-exact but still carry the heat-network cost/SAP
residual (+0.5277 SAP / −£12.16 cost, exposed by S0380.175 — cost-side,
untouched here). CH3 unchanged (code 304 community-HP COP front).
Corpus state: 37 variants EXACT on all four metrics (incl. CH1);
remaining residuals are CH2/CH4 cost+SAP, CH3 CO2+PE (HP COP), CH6
all-metric (DLF quirk). 2223 pass + 1 skip + 0 fail (tolerances 1e-4 all
metrics per S0380.181); pyright net-zero 43→43.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SAP 10.2 Appendix C §C3.2 (PDF p.51), verbatim: "CO2 emissions and
Primary Energy associated with the electricity used for pumping water
through the distribution system are allowed for by adding electrical
energy equal to 1% of the energy required for space and water heating."
Worksheet line (313) = 0.01 × [(307)+(310)]; its CO2 (372) and PE (472)
bill on the Table 12d/12e monthly factors for fuel code 50 ("electricity
for pumping in distribution network"), weighted by the monthly heat
profile per worksheet footnote (a). (307)m/(310)m = (space_demand +
hw_output) / efficiency (the cascade models a heat network's generator
efficiency as 1/DLF).
This un-defers the (372)/(472) front the post-S0380.179 handover flagged
"don't guess until the factor source is identified": the source is
§C3.2 + Table 12d/12e code 50, NOT an empirical constant. The apparent
0.1994/0.2114 "factor" is an Elmhurst DISPLAY artifact — the worksheet
shows the (372) energy column as 0.01×(307) (space only) while computing
emissions on 0.01×(307+310) per the §C3.2 text. Verified EXACT line-by-
line against the CH2 corpus worksheet: (372)=23.6007 CO2 (rating),
(472)=208.2267 PE (demand).
New `_heat_network_distribution_electricity` helper (gated on
`_is_heat_network_main`) precomputes the energy + effective CO2/PE
factors; three new CalculatorInputs fields + calculator.py CO2/PE
summation terms (0.0/None → no-op for individually-heated certs).
Closures:
CH1 (Boilers/Gas) CO2 −23.60→−0.00, PE −208.23→+0.00 — FULLY EXACT
CH3 (HP/Elec) CO2 −98.92→−75.32, PE −457.54→−249.32 (distribution
component closed; code-304 community-HP COP remains)
CH2/CH4/CH6 gain their (372)/(472) component (CO2 +23.6, PE
+208.2); dominant CHP displaced-electricity credit
residual (Table 12f + block 12b/13b) is next slice.
No regression on the other 36 corpus variants (helper returns None off
heat-network mains) + golden + U985 fixtures. 2223 pass + 1 skip + 0
fail; pyright net-zero 43→43.
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>
