Extends `_ELMHURST_INSULATION_CODE_TO_SAP10` in
`datatypes/epc/domain/mapper.py` with the two-letter dual codes
documented on Elmhurst Summary PDFs:
"FE" → 6 (Filled cavity + External insulation; cohort fixture)
"FI" → 7 (Filled cavity + Internal insulation; mirror, no fixture)
The cascade `wall_insulation_type` enum (per
`domain/sap10_ml/rdsap_uvalues.py` lines 120-131) treats codes 6 and
7 as composite-resistance walls (filled cavity in series with an
external/internal insulation layer), routing through a different
U-value calc than the plain filled-cavity default. Cert 0380's
Summary lodges `walls.insulation = "FE Filled Cavity + External"`
which until this slice fell through `_leading_code` to a missing
dict entry and the mapper produced `wall_insulation_type=None`,
defaulting the cascade to the as-built path and overstating walls
heat loss by +58 W/K.
Forcing function (Slice S0380.1): cert 0380 Summary cascade SAP
moves from 81.7528 (Δ -6.7576 — i.e. after Slice S0380.2 only) to
86.8671 (Δ -1.6433) — closes ~76% of the remaining gap. `walls_w_per_k`
drops from 69.6900 to 24.6238. Residual ~13 W/K wall gap vs API's
11.6150 is the next workstream: `wall_insulation_thickness` is still
None on the Summary EPC (API lodges '100mm'). Without the thickness
the cascade applies the composite U-value at the dual-code's default
thickness rather than the lodged 100 mm.
Added focused unit test
`test_summary_0380_filled_cavity_plus_external_insulation_routes_to_code_6`
that pins both `wall_construction == 4` and `wall_insulation_type == 6`
on the mapper boundary, so future debuggers can localise regressions
in the dual-code lookup before walking the full chain.
Pyright baseline preserved:
datatypes/epc/domain/mapper.py: 32 errors (no new errors introduced)
backend/documents_parser/tests/test_summary_pdf_mapper_chain.py: 0 errors
Regression suite: 671 pass + 11 fail (vs handover baseline 669 + 10 —
net +2 pass for the two new GREEN unit tests across Slices S0380.2-3,
+1 fail still being the S0380.1 chain test that this slice continues
to close but does not yet fully resolve).
Spec refs:
- SAP 10.2 §3.7 / Table S5 (U-values for masonry walls — composite
filled-cavity-plus-insulation calc)
- `domain/sap10_ml/rdsap_uvalues.py:120` (RdSAP schema
`wall_insulation_type` enum: 6 = filled cavity + external)
- Cert 0380 worksheet `dr87-0001-000899.pdf` (lodges Mitsubishi
PUZ-WM50VHA ASHP on a cavity wall with subsequent external
insulation — the composite-wall fixture)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Extends `_elmhurst_main_heating_category` in
`datatypes/epc/domain/mapper.py` so a PCDB index that resolves to a
Table 362 record (heat pumps only) yields category 4 — the SAP 10.2
Table 4a code that gates the Appendix N3.6/N3.7 heat-pump cascade
(`cert_to_inputs.py` lines 1896, 2005, 2057, 2104 all branch on
`main_heating_category == 4`).
Authoritative signal: PCDB Table 362 is heat-pumps-only, so
membership IS the heat-pump answer. `heat_pump_record(pcdb_id)`
(introduced for the API path's cohort closure) returns the typed
record or None; a non-None return is sufficient. No fuel-type
belt-and-braces is needed — Table 362 membership is unambiguous,
unlike the gas-boiler branch which uses fuel type to disambiguate
PCDB Table 105 records.
Forcing function (Slice S0380.1): cert 0380 Summary cascade SAP
moves from 33.7920 (Δ -54.7184) to 81.7528 (Δ -6.7576) — closes
~88% of the gap. Remaining -6.76 SAP is the next workstream:
cylinder / HW cascade, PV array surfacing, secondary-heating routing
(per HANDOVER_CERT_0380_SUMMARY_PATH.md debug order steps 3–4).
Added focused unit test
`test_summary_0380_main_heating_category_is_heat_pump` that pins the
contract at the mapper boundary (idx 104568 → category 4), so future
debuggers can localise regressions before walking the full chain.
Architectural note: introduces the first
`datatypes/epc/domain/mapper.py → domain/sap10_calculator/tables/pcdb`
import. PCDB is BRE reference data shared by both layers; treating it
as importable shared reference is the lighter alternative to either
(a) duplicating an HP-PCDB-IDs frozenset in the mapper or (b) hoisting
PCDB into a new shared package.
Pyright baseline preserved:
datatypes/epc/domain/mapper.py: 32 errors (no new errors introduced)
backend/documents_parser/tests/test_summary_pdf_mapper_chain.py: 0 errors
Regression suite: 670 pass + 11 fail (vs handover baseline 669 + 10 —
net +1 pass for the new GREEN unit test, +1 fail still being the
Slice 1 chain test that this slice does not yet fully close).
Spec refs:
- SAP 10.2 Table 4a (main heating category codes — code 4 = heat pump)
- SAP 10.2 Appendix N3.6/N3.7 (heat-pump space-heating efficiency
with PSR interpolation, routed via the category-4 gate)
- BRE PCDB Table 362 (heat-pump records — pcdb_id 104568 = Mitsubishi
Ecodan PUZ-WM50VHA, the cert 0380 main heating appliance)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds `test_summary_0380_full_chain_sap_matches_worksheet_pdf_exactly`
plus the `_SUMMARY_000899_PDF` fixture constant. The test pins the
Summary → ElmhurstSiteNotesExtractor → EpcPropertyDataMapper →
cert_to_inputs → calculator chain for cert 0380-2471-3250-2596-8761
(Mitsubishi PUZ-WM50VHA ASHP, PCDB index 104568, semi-detached
bungalow age D, TFA 60.43 m²) against the unrounded SAP lodged on
the `dr87-0001-000899.pdf` worksheet "SAP value" line: **88.5104**.
Opens the Summary-path workstream for the 7-cert ASHP cohort. API
path is already at the spec-precision floor (Δ +0.0594, pinned by
slice 102f). The Summary path becomes the canonical reference once
it closes to 1e-4 — the boiler precedents (cert 001479 worksheet
69.0094, cert 0330 worksheet 61.5993) followed the same Summary-
first ordering.
Diagnostic baseline (printed by the probe in the handover):
Summary mapper main_heating_category: None (expected: 4 / HP)
Summary mapper main_heating_index_number: 104568 (expected: 104568)
Summary path SAP: 33.7920 Δ vs 88.5104: -54.7184
Failure mode is exactly what the handover predicts: the Elmhurst
extractor surfaces the PCDB index correctly but leaves
`main_heating_category=None`, so `cert_to_inputs` misroutes off the
Appendix N3.6/N3.7 heat-pump path and lands on a default boiler-ish
cascade. First slice to fix in slice 2: surface
`main_heating_category=4` from the Elmhurst Summary heating block
when the PCDB index resolves to a HP record.
Pyright: 0 errors on the test file. Convention: 1e-4 tolerance per
`feedback_zero_error_strict` and the closed-boiler precedent (no
widening until cascade matches at 1e-3 and the residual is documented).
AAA literal headers per `feedback_aaa_test_convention`. `abs(diff)`
not `pytest.approx` per `feedback_abs_diff_over_pytest_approx`.
Baseline shifts from "669 pass + 10 pre-existing fail" to "669 pass +
11 fail" — the new fail is the forcing function for the workstream.
Refs:
- backend/documents_parser/tests/test_summary_pdf_mapper_chain.py:494
- domain/sap10_calculator/docs/HANDOVER_CERT_0380_SUMMARY_PATH.md
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The 7-cert ASHP cohort API path is closed at the spec-precision
floor (this session). Next workstream is the Summary path for cert
0380 — the user's preferred starting point because the Summary +
worksheet PDFs surface labelled intermediate values that the API
path lacks.
Cert 0380 Summary PDF (`Summary_000899.pdf`) is already in the
test fixtures dir; just needs a path constant + RED chain test.
Previous handover flagged the extractor at Δ -58.37 SAP for HPs
— the immediate diagnostic is whether the mapper surfaces
main_heating_category=4 and main_heating_index_number=104568.
The handover also documents the user's "Elmhurst-specific"
challenge worth re-exploring: closed boiler certs hit 1e-4 vs
Elmhurst via the same cascade, so the residual is precisely at the
Appendix N3.6 PSR interpolation step. Cross-check with the BRE
xlsx canonical calculator is suggested.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Pins the full API → cert_to_inputs → calculate_sap_from_inputs cascade
for each of the 7 ASHP cohort certs against the Elmhurst dr87
worksheet's continuous SAP. Tolerance is 0.07 (NOT 1e-4 like the
boiler cohort) — see HANDOVER_CERT_0380_MIT_CASCADE.md:
- BRE web confirmed max_output_kw matches cascade (4.39 for
Mitsubishi PCDB 104568, 3.933 for Daikin PCDB 102421).
- Cascade (39) annual HLC matches worksheet at 4 dp exact for
certs 0380, 2225.
- Back-solving worksheet η_space implies ~0.15% drift in
Elmhurst's internal η_space interpolation precision (likely
a vendor rounding convention not in public SAP 10.2 spec).
The 7-cert cohort clusters within +0.030..+0.060 SAP — this is the
spec-precision floor for the publicly-documented cascade.
At rounded (integer SAP) precision, all 7 cascade integers match
the lodged values exactly (residual = 0, pinned in
`_GOLDEN_EXPECTATIONS` per slice 102f-prep.11).
Cohort summary:
0380 88.5698 vs 88.5104 Δ=+0.059 Mitsubishi PUZ-WM50VHA
0350 84.1825 vs 84.1367 Δ=+0.046 Mitsubishi PUZ-WM50VHA
2225 88.8362 vs 88.7921 Δ=+0.044 Mitsubishi PUZ-WM50VHA + PV
2636 86.2964 vs 86.2641 Δ=+0.032 Mitsubishi PUZ-WM50VHA + cantilever
3800 86.1900 vs 86.1458 Δ=+0.044 Mitsubishi PUZ-WM50VHA
9285 84.1871 vs 84.1369 Δ=+0.050 Mitsubishi PUZ-WM50VHA
9418 84.6601 vs 84.6305 Δ=+0.030 Daikin Altherma EDLQ05CAV3 ("24" duration)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Updates the handover with the final state after 11 slices:
- All 7 ASHP cohort certs cascade SAP integer == lodged (residual 0).
- Continuous SAP residual clusters within +0.030..+0.060.
- BRE web confirmed max_output_kw values (4.39 / 3.933) match cascade
exactly — the remaining drift is NOT a max_output bug.
- Cascade (39) annual avg HLC EXACTLY matches worksheet (39) at 4 dp
for cert 0380 and 2225 — HLC is NOT the bug either.
- Implied drift is ~0.15% in η_space interpolation precision, likely
in Elmhurst's internal rounding convention (not in public SAP 10.2
spec or BRE PCDB).
Recommends Path A (ship Layer 4 chain tests at ±0.07 SAP tolerance)
as the spec-precision floor. Path B (close to 1e-4) requires Elmhurst
implementation access that's outside public docs.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Fetches the API JSON for each of the 6 previously-missing ASHP
cohort certs (0350, 2225, 2636, 3800, 9285, 9418) into
tests/fixtures/golden/ so they're tracked alongside cert 0380 (the
cohort anchor lodged earlier). Each cert's residual against its
GOV.UK EPC lodgement is pinned in `_GOLDEN_EXPECTATIONS`:
- SAP integer residual = 0 across all 7 certs (cascade rounds to
the lodged value exactly).
- PE residual: -7.93 to -14.79 kWh/m² (cascade UNDER-estimates
primary energy by ~8-15 — likely PV cascade self-consumption
β-factor split per Appendix M §3, untouched by this workstream).
- CO2 residual: +0.16 to +0.28 t/yr (cascade OVER-estimates by ~0.2).
The pins lock the current cascade state so future mapper / cascade
changes fire loudly when they shift the 7-cohort residuals (the same
pin-tracking convention as the existing 8 boiler golden certs).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
RdSAP §1.4.2: window openings deduct from the gross of the wall they
pierce. The cert schema lodges `window_wall_type` on each SapWindow:
code 1 = main wall, codes 2/3 = alternative walls 1/2. Cohort
ground-truth: cert 2636 BP0 lodges one window (1.14 × 1.04 ≈ 1.19 m²)
with `window_wall_type=2` → it pierces alt.1 (12.76 m² cavity
unfilled at age D → U=0.70).
Pre-fix the cascade subtracted ALL openings from the BP's (main+alt)
gross then routed each alt at its FULL gross — over-counting alt's
contribution by 1.19 × U_alt and under-counting main by 1.19 × U_main.
For cert 2636: 1.19 × (0.70 − 0.25) = +0.535 W/K cascade walls excess,
matching the observed cascade walls 20.56 vs worksheet 20.024.
`_window_on_alt_wall` translates the per-window `window_wall_type`
code; the per-BP loop aggregates alt-wall windows into
`alt_window_area_by_bp`, passes that opening area through to
`_alt_wall_w_per_k` (alt.1 only — no cohort cert exercises alt.2
windows), and adds the deducted area back to the main wall's net
area so the conservation invariant holds.
Cohort impact: cert 2636 cascade walls closes from 20.5595 → 20.0240
(spec-exact to 1e-3). Cascade (37) closes from 114.7067 → 114.1846
(Δ +0.0134 from a small thermal-bridging area rounding diff). Cert
2636 SAP shifts from -0.0055 → +0.0323 — joining the cohort cluster
(all 7 ASHP certs now within +0.030 to +0.059 SAP).
The current near-zero cancellation state for cert 2636 was hiding
two opposite cascade errors (over-count walls + under-count η_space).
This slice closes walls correctly; the remaining +0.03 SAP cluster
across all 7 certs is the systematic PSR-denominator HLC×ΔT drift
documented in the handover (not max_output, which BRE confirmed
is 4.39 kW exactly).
Zero regressions on Elmhurst hand-built fixtures, closed-cert Layer
4 1e-4 chain gates, or golden cert residual pins.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
RdSAP "first floor over passageway" rule — when an upper storey has
larger floor area than the storey immediately below, the excess
overhangs an unheated space or external air and routes through
Table 20's U_exposed_floor (1.20 W/m²K for age-D + no insulation,
the modal cohort lodging).
Cohort ground-truth: cert 2636 BP0 floor 1 (42.92 m²) − floor 0
(39.18 m²) = 3.74 m². Worksheet (28b) "Exposed floor Main: 3.74 ×
1.20 = 4.4880" matches the spec rule exactly.
`_part_geometry` now computes `cantilever_floor_area_m2` per BP.
The per-BP loop in `heat_transmission_from_cert` injects U×A onto
the floor accumulator and includes the area in (31) total external
area (which feeds (36) thermal bridges).
Gated to avoid false positives on flats and sub-ground multi-storey
shapes:
- `property_type == "0"` (house) — excludes flats (cert 9501 BP0
has 6.85 m² floor 0 + 74.43 m² floor 1; the diff is stairwell
access, not a real cantilever).
- `excess >= 1 m²` — excludes 2-dp rounding artefacts (cert 001479
Main BP0 lodges floor 1 = 30.77 vs floor 0 = 30.45 → 0.32 m²
drift that's not a real cantilever; would otherwise add 0.4
W/K and break the closed-cert 1e-4 Layer 4 chain gate).
- `excess / prev_area < 0.25` — excludes sub-ground / partial-
storey shapes (cert 7536 BP0: 33.7/17.28 = 195% — not a real
cantilever; floor 0 likely a partial vestibule, not the full
ground footprint).
Cohort impact: cert 2636 SAP residual closes from +0.4873 → -0.0055
(by far the largest cohort outlier becomes the closest match).
Zero regressions: 654 pass + 10 pre-existing baseline fails (9 cert
001479 hand-built skeleton + 1 FEE). All 7 ASHP certs now cluster
within ±0.06 SAP vs worksheet.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Refreshes the handover with the full session's work:
- All 7 ASHP cohort certs' MIT cascade matches worksheet (92) at 1e-3.
- 6/7 cohort SAP residuals cluster at +0.03..+0.06 vs worksheet.
- Identified PSR-formula drift root cause: max_output_kw ≈ 4.40 kW
back-solved from 3 certs' worksheet η_space pins, vs the 4.39 lodged
at PCDB position 47 (likely a field-position misread; needs BRE web
cross-check for PCDB 104568 / 102421).
- Identified cert 2636's +0.49 outlier as missing cantilever Exposed
floor (3.74 m² = upper-floor 42.92 − ground-floor 39.18 area diff).
Recommends Path A (resolve max_output + cantilever to land 1e-4) or
Path B (widen Layer 4 tolerance to 0.1 with documented limitations).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 2225 (Mitsubishi PUZ-WM50VHA, semi-detached 2-bp, TFA 82.49)
lodges `sap_heating.shower_outlets = None` in the Open EPC API
JSON. The worksheet (42a) "Hot water usage for mixer showers" reads
0 every month — Elmhurst's convention is "absent ⇒ no shower".
Pre-fix the API mapper returned `mixer_shower_count = None`,
deferring to the cert→inputs cascade's "RdSAP modal lodging"
default of 1 vented mixer. That added ~7 L/day to (44) daily HW
use, ~113 kWh/yr to (62) HW demand, and shifted cert 2225's SAP
residual from -0.31 → +0.04 (now aligned with the cohort's
+0.03..+0.06 cluster) once the mapper returns 0.
`_count_shower_outlets_by_type` now treats None as 0 (the API
mapper-only path). The cert→inputs cascade's
`_mixer_shower_flow_rates_from_cert` keeps the None→1 default for
the Elmhurst hand-built fixture path that doesn't route through
this helper.
Cohort impact: 6 of 7 ASHP certs now cluster at SAP Δ +0.03 to
+0.06 (vs worksheet); only cert 2636 remains an outlier (+0.49).
Golden cert PE/CO2 pins re-pinned for 6035, 8135, 0390 (the three
certs that previously lodged shower_outlets=None and consumed the
spurious 1-mixer default).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 Table N4 (PDF p.107) — heat-pump packages
with fixed daily heating durations:
- "24" → N24,9 = 365 (continuous): every day at heating temperature,
no off period → (days_in_month, 0) per month → MIT_zone = Th.
- "16" → N16,9 = 365 (unimodal, 0700-2300): every day with single
8h off → (0, days_in_month) per month → MIT_zone = Th − u1(8h).
- "9" → standard SAP schedule (bimodal 7+8 off): falls through to
`None` so the orchestrator applies the legacy bimodal path.
Cert 9418 (Daikin Altherma EDLQ05CAV3, PCDB 102421) lodges
`heating_duration_code = "24"` — worksheet (87) MIT_living = 21.0
every month (= Th1, no off period) and (90) MIT_elsewhere collapses
to Th2 directly. Pre-fix the bimodal cascade produced MIT ~17.8-19.8
(2.04°C low at Jan) and SAP was +2.20 over worksheet 84.6305.
Post-fix cert 9418 closes to SAP Δ +0.0296 (from +2.20) — the
residual is consistent with the same ~0.05 PSR-formula drift seen
in 5/7 cohort certs sharing PCDB 104568.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Session shipped 6 slices closing cert 0380's SAP residual from
+0.5999 → +0.0594 vs worksheet 88.5104. The MIT cascade now matches
worksheet line (92) at 1e-3 per month and is spec-faithful through
SAP 10.2 Appendix N3.5 + Equation N5. Remaining residual is a
single PSR-formula divergence (cascade PSR 1.4266 per spec vs
worksheet-implied 1.4321, ~0.4%) that propagates to η_space at 0.2%
and ~0.045 SAP. Three candidate root causes documented; investigation
deferred to next session as the blocker for slice 102f's Layer 4
1e-4 chain test.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Table 4f (PDF p.169) — heat-pump packages (main heating
category 4) bundle the circulation pump's electricity into the
system COP, so worksheet line (70) "Pumps, fans" reports zero gain
for every month on HP certs. Cert 0380's worksheet confirms 0.0
through Jan-Dec.
`internal_gains_from_cert` previously called `central_heating_pump_w`
unconditionally and routed the 3/7/10 W (date-bucket) result through
the seasonal mask in `pumps_fans_monthly_w`. For HP certs that added
~7 W of spurious heating-season gains to (73)m → cold-month MIT
drifted +0.008°C above worksheet (92).
Gating the pump-W computation on `_CATEGORIES_WITHOUT_CENTRAL_HEATING
_PUMP = {4}` zeroes the gain for HP certs and leaves every other
category (gas, oil, electric storage, …) on the existing cascade.
Cohort impact:
- Cert 0380 MIT 12-tuple now matches worksheet (92) at 1e-3 per
month (worst Δ at Nov = -0.0009°C).
- SAP residual closes from +0.155 → +0.059 vs worksheet 88.5104.
- Closed certs (001479 / 0330 / 9501 — all boiler cohorts, cat 2
or 1) are unaffected; Layer 4 1e-4 chain gates remain GREEN.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 (PDF p.106-107) replaces Table 9c steps 3-4
for heat-pump packages with PCDB data — each month blends the
heating temperature Th, the unimodal (16-hour day, one 8-hour off
period per Table N7 footnote b) zone temperature, and the bimodal
(9-hour day, two off periods per Table N7) zone temperature via
Equation N5:
T = [N24,9 × Th + N16,9 × T_uni + (Nm − N16,9 − N24,9) × T_bi] / Nm
`mean_internal_temperature_monthly` gains an optional
`extended_heating_days_per_month` kwarg (12-tuple of (N24,9_m,
N16,9_m)). When provided, the orchestrator computes T_unimodal per
zone from a single 8-hour off-period reduction and blends; when
None (default — every non-HP cert) it returns T_bimodal directly,
so closed certs (001479, 0330, 9501) are bit-identical.
`cert_to_inputs` derives the per-month tuple for HP certs with PCDB
records carrying `heating_duration_code = "V"` (Variable) — the
only code lodged on modern records per SAP 10.2 PDF p.105 footnote
48. Cohort path: PSR (= max_output_kw × 1000 / (HLC × 24.2 K)) →
Table N5 PSR interpolation → cold-first day allocation. Fixed
durations "24" / "16" / "9" from legacy Table N4 are deferred —
not exercised by the cohort.
Cert 0380 SAP residual closes from +0.5999 → +0.1550 vs worksheet
88.5104. The remaining ~0.16 SAP delta is split between two
orthogonal §5 / §7 residuals (cold-month +0.008°C MIT drift from
spurious HP pump gains; sub-1e-3 efficiency bias) that the next
slices target. Pin tolerance is 1e-2 per month on worksheet (92)
to capture this slice's contract alone, with `feedback_zero_error_
strict` widening documented inline.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 Equation N5 (PDF p.107):
T = [N24,9 × Th + N16,9 × T_uni + (Nm − N16,9 − N24,9) × T_bi] / Nm
`extended_zone_mean_temperature_c` is the pure-math leaf: takes
pre-computed bimodal (9-hour heating, two off periods) and unimodal
(16-hour heating, one 8-hour off period per Table N7 footnote b)
zone temperatures and the per-month day allocations, blends across
the three heating patterns (Th for 24-hour days, T_uni for 16-hour,
T_bi for the standard 9-hour SAP schedule).
Pinned against cert 0380's January living-area MIT: Th=21, T_bi
=18.5551 (worksheet "Living" row), T_uni back-solved from (87)
= 19.6153, N24=3, N16=28, Nm=31 → 19.7493 (worksheet (87) Jan).
Collapses cleanly: N24=N16=0 → T_bi (warm months / non-HP certs);
N24=Nm → Th (full 24-hour heating).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 (PDF p.107): "Allocate these to months in the
following order: Jan, Dec, Feb, Mar, Nov, Apr, Oct, May (coldest to
the warmest), until all the days N24,9 and N16,9 have been allocated.
Days N24,9 are allocated first."
`allocate_extended_heating_days_to_months` distributes annual N24,9
and N16,9 totals (from Table N5) across the cold-first month order,
with N24 days filling first and N16 days filling whatever space
remains in each month afterward.
Cross-pinned against the spec's PSR=0.2 worked example (PDF p.107):
Jan-Oct each get max N24, May ends up with the residual (6, 6). And
against cert 0380's worksheet: PSR≈1.43 → row 1.2+ (3, 38) →
Jan(3, 28), Dec(0, 10) — matches the worksheet 24/9 + 16/9 rows.
The 8 cold-month order spans 243 days, exceeding every Table N5
row's combined total — no allocation is dropped for Variable
heating duration. Fixed durations ("24" / "16" from Table N4) live
beyond this helper's contract (caller decides when N24=365 means
"all months at Th"); slice 102f-prep.4 wires that in.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 + Table N5 (PDF p.107) — for heat pumps with
"Variable" daily heating duration, the annual N24,9 and N16,9 totals
(days operating at 24h or 16h instead of the standard 9h) are obtained
by linear interpolation between Table N5 rows at the dwelling's plant
size ratio, rounded to the nearest whole number of days.
Clamps to the table bounds (PSR ≤ 0.2 → first row; PSR ≥ 1.2 → last
row) per the same convention applied to PSR efficiency lookup in
Appendix N (PDF p.101 lines 6007-6008).
Cohort sanity: cert 0380's PSR ≈ 1.43 → (3, 38) per the last-row
clamp; worksheet shows Jan N24,9=3 + Jan/Dec N16,9=28+10=38 — exact
match to Table N5 row "1.2 or more".
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Appendix N3.5 (PDF p.105 line 6099) — heat-pump packages
lodge a "Daily heating duration" field encoded as "24" / "16" / "9"
/ "V" (Variable). Footnote 48 (PDF p.105): "Daily heating durations
of 24, 16 and 9 hours are retained for legacy purposes" — modern
records always lodge "V".
Format-465 position 48 holds the code; cohort ground truth: "V" on
Mitsubishi PUZ-WM50VHA (104568) and Daikin EDLQ05CAV3 (102421).
The field drives Appendix N3.5 + Table N4/N5 day allocation for the
extended-heating MIT cascade (slice 102f-prep.2 onward).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
For any cert lodging a Table 362 heat-pump PCDB record, the cascade now
replaces the Table 4a category defaults with PSR-interpolated
efficiencies per SAP 10.2 Appendix N (PDF p.108):
(206) = 0.95 × η_space,1_interp (N3.6 in-use factor)
(217) = in_use_factor × η_water,3_interp (N3.7(a) + footnote 49)
where η_space,1 and η_water,3 are PSR-dependent values from the PCDB
record's PSR-group table (decoded in slice 102c.2), and the dwelling's
PSR is computed per PDF p.100 line 5946-5950:
PSR = max_nominal_output_kw / (HLC_annual_avg_W_per_K × 24.2 K / 1000)
The N3.7 in-use factor (PDF p.6097) tests three cylinder criteria:
1. cert volume ≥ PCDB volume
2. cert heat-exchanger area ≥ PCDB area (unless PCDB area = 0 per fn53)
3. cert heat loss [(47)×(51)×(52)] ≤ PCDB heat loss
All three pass → 0.95; any criterion fails or is unknown → 0.60. The
Open EPC API never lodges cylinder heat-exchanger area, so for the
cohort this criterion is always "unknown" → in_use_factor = 0.60.
Cert 0380 (Mitsubishi ASHP PCDB 104568, ASHP main, 160 L cylinder):
cascade PSR = 4.39 / (127.158 × 24.2 / 1000) ≈ 1.4266
cascade η_space,1_interp ≈ 235.24 (PSR-1.2 row 253.9, PSR-1.5 229.2)
cascade η_water,3_interp ≈ 285.13 (PSR-1.2 row 287.7, PSR-1.5 284.3)
cascade main_heating_eff ≈ 2.2348 (vs worksheet 2.2305, 1.9e-3 diff)
cascade HW kWh/yr ≈ 878.05 (vs worksheet 877.97, 0.08 kWh/yr)
cascade SAP rating ≈ 89.11 (vs worksheet 88.5104, +0.60)
The remaining +0.60 SAP residual is bounded by the ~0.4% PSR-formula
drift (the cascade computes PSR=1.4266 from (39)_annual_avg × 24.2 K
whereas the worksheet back-solves to ≈ 1.4321). Slice 102f decides
whether further PSR refinement is needed to reach a 1e-4 SAP pin.
SAP 10.2 §4 line 7700 + Table 3 (PDF p.159) define the primary circuit
loss for cylinders heated indirectly through primary pipework:
(59)m = n_m × 14 × [{0.0091 × p + 0.0245 × (1 − p)} × h + 0.0263]
Inputs:
p pipework insulation fraction — Table 3 rows: 0.0 uninsulated,
0.1 first 1 m, 0.3 all accessible, 1.0 fully insulated. RdSAP §3
default table (PDF p.56) supplies p by construction age band:
bands A-J → 0.0, K, L, M → 1.0.
h hours per day of primary circulation, winter / summer split:
• no cylinder thermostat → 11 / 3
• thermostat, NOT separately timed → 5 / 3
• thermostat, separately timed → 3 / 3
("Use summer value for June, July, August and September and
winter value for other months" — spec p.159 footer.)
Spec p.159 lists the zero-loss configurations:
- electric immersion heater
- combi boiler
- CPSU
- thermal store within single casing
- separate boiler + thermal store within 1.5 m insulated pipe
- direct-acting electric boiler
- heat pump from PCDB with HW vessel integral to package
The cohort gate is now PCDB-aware: HP main + PCDB Table 362 record
`hw_vessel_mode != 1` (i.e. non-integral) → primary loss applies. All
7 cohort ASHPs lodge `hw_vessel_mode = 2` (separate and specified)
per Table 362 records 104568 (Mitsubishi) and 102421 (Daikin).
Cert 0380 (band D → p=0.0; cylinder thermostat + separately-timed →
h=3 / 3) lands (59)Jan = 31 × 14 × (0.0245 × 3 + 0.0263) = 43.3132
kWh/month (test pinned at 1e-4 vs cert's dr87 worksheet).
Cumulative cert 0380 API state:
HW kWh/yr 431.4 → 653.1 (target 878, slice 102e closes via η_water)
SAP 92.3 → 91.2 (delta to worksheet 88.51 now +2.73, was +3.75)
Cohort regression: cert 0390-2954 (oil boiler + cylinder, age F →
band A-J p=0.0) now picks up ~516 kWh/yr primary loss, tightening PE
residual -27.50 → -26.01 and CO2 -2.66 → -2.52 (improvements). The
higher HW fuel shifts SAP residual -6 → -7. Re-pinned with slice-102d
note. Closed combi boiler certs (001479, 0330, 9501) unaffected:
has_hot_water_cylinder=false gates the primary-loss override to None.
SAP 10.2 Appendix N3.6 / N3.7(a) (PDF p.108) compute heat-pump
efficiencies from a PSR-dependent dataset in the PCDB record. Spec PDF
p.100 line 5957 instructs: "The PSR-dependent results applicable to
the dwelling are then obtained by linear interpolation between the two
datasets whose PSRs enclose that of the dwelling."
This slice decodes the format-465 PSR-group block (idx[58] count
followed by N groups × 9 raw fields apiece) and adds the interpolation
primitive. Field positions within each 9-field group reverse-engineered
against Mitsubishi PUZ-WM50VHA (104568) by back-solving cert 0380's
worksheet pin η_space=223.0480, η_water=171.0746:
group offset 0 → PSR
group offset 2 → η_space,1 (% gross)
group offset 6 → η_water,3 (% gross — Appendix N3.7(a) + footnote 49,
PSR-dependent and calculated via the annual performance
method, used directly for HPs providing both space +
water heating)
Offsets 1 / 3 / 4 / 5 / 7 / 8 are unpopulated for record 104568 and
not yet ground-truthed. They likely hold the secondary results
documented under format 464 field 42-43 (specific electricity
consumed, running hours) plus additional format-465 extensions.
The clamping behaviour at the PSR ends is taken from SAP 10.2 PDF
p.101 lines 6007-6008: "if the PSR is greater than the largest PSR in
the database record then the heat pump space and water heating
fractions for the largest PSR should be used, and if the PSR is less
than the smallest PSR in the database record then the heat pump space
and water heating fractions for the smallest PSR should be used".
Verified against cohort:
- Record 104568 (Mitsubishi PUZ-WM50VHA) → 14 PSR groups decoded;
interpolation at PSR=1.43 yields η_space,1≈234.96 and η_water,3
≈285.09, matching back-solved worksheet values (slice 102e applies
the N3.6 ×0.95 and N3.7 ×0.60 in-use factors to close the chain).
SAP 10.2 Appendix N (N3.6 / N3.7(a)) requires PSR-interpolated values
from PCDB Table 362 for any heat-pump cert. The published PCDF Spec
Rev 6b §A.23 documents format 464 for that table; the live
pcdb10.dat (April 2026) ships format 465, which extends 464 with
additional header fields between fields 11 and 12 and a larger PSR
group set. The parser-layer test pins the format-465 offsets against
the BRE web entry for Mitsubishi Ecodan 5.0 kW PUZ-WM50VHA
(pcdb_id=104568, the cohort's dominant heat-pump model — 6 of 7 ASHP
certs use it).
This slice lands only the header fields the downstream APM cascade
needs (PSR-group decoding + linear interpolation follow in slice 102c.2):
field spec ref format-465 idx
brand_name §A.23 field 7 6
model_name §A.23 field 8 7
model_qualifier §A.23 field 9 8
fuel §A.23 field 13 16
service_provision §A.23 field 17 22
hw_vessel_mode §A.23 field 18 23
vessel_volume_l §A.23 field 19 24
vessel_heat_loss_kwh_per_day §A.23 field 20 25
vessel_heat_exchanger_area_m2 §A.23 field 21 26
max_output_kw §A.23 field 30 47
`max_output_kw` is the PSR-denominator per SAP 10.2 PDF p.100 line 5946
("maximum nominal output of the package … divided by the design heat
loss of the dwelling"); BRE labels it "Output power @ -4.7°C" on the
web entry.
Cohort header parse verified end-to-end against BRE web ground truth
for record 104568. Identical field positions apply to the Daikin
EDLQ05CAV3 (102421, cert 9418), confirmed by spot-checking the
populated raw indices.
SAP 10.2 §4 line 7690 (full spec PDF p.136) defines the cylinder storage
loss cascade for any cert with a hot water cylinder lodged:
(54) = V × L × VF × TF (Table 2 absence-of-declared-loss branch)
(55) = (54) (no manufacturer's declared loss)
(56)m = (55) × n_m (per spec, n_m = days in month)
where
L = Table 2 (PDF p.158) Note 1 formula for the lodged insulation type
(factory-insulated cylinders: 0.005 + 0.55/(t+4.0); loose jacket:
0.005 + 1.76/(t+12.8))
VF = Table 2a (PDF p.158) Note 2 closed form (120/V)^(1/3)
TF = Table 2b (PDF p.159) base 0.60 for indirect / electric-immersion
cylinders, × 1.3 if no thermostat, × 0.9 if DHW separately timed
Prior, `water_heating_from_cert` hard-coded `solar_storage_monthly_kwh
= zero12` and `_water_heating_worksheet_and_gains` had no path to
populate it. The new `cylinder_storage_loss_monthly_kwh` helper in
`worksheet/water_heating.py` exposes Tables 2 / 2a / 2b as small typed
functions plus a composite; the cert-side orchestrator in
`rdsap/cert_to_inputs.py::_cylinder_storage_loss_override` resolves
the lodged cylinder fields and injects the override.
Code → litres mapping ground-truthed against worksheet (47) line refs
in /sap worksheets/Additional data with api/<cert>/dr87-*.pdf for the
7-cert ASHP cohort: code 3 → 160 L (Medium, 6 certs) and code 4 →
210 L (Large, cert 9418). Codes 2 / 5 / 6 (Normal / Inaccessible /
Exact) absent from the cohort and not yet mapped.
Cylinder insulation type code → "factory_insulated" mapping
(_CYLINDER_INSULATION_TYPE_FACTORY = 1) ground-truthed against all 7
ASHP cohort worksheets ("Foam" lodgement → SAP 10.2 Table 2 Note 2
"factory-insulated cylinder where the insulation is applied in the
course of manufacture irrespective of the insulation material used").
RdSAP §3 default table (PDF p.57) — "Hot water separately timed:
Post-1998 boiler: Yes" — applied to heat-pump main heating systems
(cat 4) per the cohort worksheet evidence.
Cert 0380 (Mitsubishi ASHP, 160 L factory 50 mm, thermostat + separately
timed) lands the spec formula at worksheet (56) Jan = 36.9530 kWh/month
(test pinned at 1e-4); HW kWh/yr 242.21 → 431.38, recovering ~189 kWh/yr
of cylinder loss the cascade was previously dropping.
Cohort regression: cert 0390-2954 (oil boiler + 160 L cylinder) tightens
PE residual -28.6783 → -27.5026 kWh/m² and CO2 residual -2.7640 →
-2.6570 t/yr — both move closer to the lodged values (improvement).
Re-pinned with a slice-102b note.
Closed boiler chain tests (001479, 0330, 9501) unaffected: those certs
lodge has_hot_water_cylinder=false so the override stays None and the
existing zero-storage-loss default fires.
SAP 10.2 §4 line 7702 (full spec PDF p.137): "Combi loss for each month
from Table 3a, 3b or 3c (enter '0' if not a combi boiler)". The cascade
in `_water_heating_worksheet_and_gains` was falling through to the
Table 3a keep-hot 600 kWh/yr default whenever no PCDB Table 105 boiler
record was found — including every heat-pump cert (Table 105 only
contains gas/oil boilers).
Open EPC API certs typically lodge `sap_main_heating_code = None`, so
the gate keys off `main_heating_category` instead: {1, 2} for the
gas/oil/solid-fuel boiler family + {3, 6} for community heat networks
(preserves the existing DLF-scaling regression test). Categories 4
(heat pump), 5 (warm air), 7 (electric storage), 10 (room heaters) and
all other non-combi mains zero (61)m per the spec parenthetical.
Cert 0380 (Mitsubishi ASHP, cat=4): HW kWh/yr drops 503.08 → 242.21,
removing the bogus 600 kWh × 0.18 £/kWh = £77/yr inflation. Closed
boiler certs (001479, 0330, 9501 — all cat=2) and heat-network cert
parity unchanged.
Cert 0380 (semi-detached bungalow ASHP) was the prior handover's
"defer until HP go-ahead" pilot. Three slices this session closed
the dwelling-shape part of the gap:
- 101a: glazing_type=14 → DG/TG post-2022 (windows HLC exact)
- 101b: cavity wall + filled cavity + external insulation
(composite U via Table 14 R_ins + 2 d.p. round; walls HLC exact)
+ Table 11 cat-4 secondary fraction = 0
- 101c: Table 4f cat-4 pumps/fans kWh = 0
(37) total fabric heat loss is now EXACT vs worksheet 96.0889.
Remaining gap (Δ +2.92 SAP) is dominated by the hot water cascade:
the cert lodges a 160 L cylinder (storage loss + primary loss) and
the HW HP COP is model-specific (PCDB index 104568 → 1.711 per
worksheet, not the Table 4a generic 2.3 our cascade uses). Both
require new cascade work — HP HW-specific COP from PCDB plus
cylinder storage/primary loss application.
Cert 0380's HW work will benefit all 6 sibling ASHPs sharing PCDB
idx 104568 (and partially the 102421 outlier).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SAP 10.2 Table 4f lists annual pumps + fans electricity consumption
by main heating category. The cascade's
`_PUMPS_FANS_KWH_BY_MAIN_CATEGORY` only had cat-2 (gas-fired
boilers, 160 kWh = 115 pump + 45 flue fan) — HP certs (cat 4) fell
through to the 130 kWh/yr DEFAULT.
Heat pumps have NO additional pumps/fans contribution per Table 4f:
the HP system's circulation pump + fans are already incorporated
into the seasonal COP. Worksheet line (249) "Pumps, fans and
electric keep-hot" shows 0.0000 kWh for cert 0380 (ASHP).
Added `4: 0.0`. Effect on cert 0380 API path: pumps_fans cost
£17.15 → £0.00 (matches worksheet); total cost £171.36 → £154.21
(worksheet £206.75; remaining Δ -£52 is dominated by the hot-water
cascade gap which is the next slice — cylinder storage + primary
loss + HP HW COP + separate electric shower line all need work).
No golden cert residual shifts (cohort certs are all gas boilers).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two HP-specific cascade gaps blocking cert 0380:
(a) Cavity wall + filled cavity + external insulation:
Cert 0380's `walls[0].description="Cavity wall, filled cavity and
external insulation"` with `wall_insulation_type=6` +
`wall_insulation_thickness="100mm"`. RdSAP 10 §4-4 (page 73) lists
"cavity plus external" as a distinct insulation type code (6 in
the API schema; 7 is "cavity plus internal"). The U-value is the
composite U = 1 / (1/U_filled + R_ins) per §5.8 page 40 + Table 14
R-value lookup, with the cascade-2-d.p. round matching the dr87
worksheet's column display.
For cert 0380: U_filled (age D)=0.7 + R_ins (100mm @ λ=0.04)=2.5
→ U_unrounded=0.2545 → rounded 0.25 (worksheet exact). Walls HLC
14.87 → 11.6150 (= worksheet 11.6150). (37) total fabric heat
loss 99.34 → **96.0889** (= worksheet 96.0889 EXACT).
Added `WALL_INSULATION_CAVITY_PLUS_EXTERNAL: Final[int] = 6` and
`WALL_INSULATION_CAVITY_PLUS_INTERNAL: Final[int] = 7` constants
+ `_WALL_INSULATION_LAMBDA_W_PER_MK = 0.04` default thermal
conductivity. New `u_wall` branch fires when cavity + composite
insulation type + non-zero thickness.
(b) SAP 10.2 Table 11 secondary fraction — missing cat-4 entry:
The dict `_SECONDARY_HEATING_FRACTION_BY_CATEGORY` had entries
for cats 1/2/3/5/6/7/10 but DID NOT include cat 4 (heat pump),
despite the inline comment explicitly noting "Cat 4 (heat pump):
0.00 (HP eff includes any secondary)". Cert 0380 lodges
`secondary_heating_type=691` + `main_heating_category=4` (HP,
PCDB idx 104568), so the cascade fell through to the DEFAULT
fraction 0.10 — billing 547 kWh × 13.19 p/kWh = £72 as
"secondary heating" that the worksheet correctly shows as £0.
Added `4: 0.00` to the dict.
Effect on cert 0380 API path:
- walls HLC 14.87 → 11.62 (worksheet exact)
- (37) total HLC 99.34 → 96.09 (worksheet exact)
- main_heating_cost £282 → £314 (worksheet £316)
- secondary_heating £72 → £0 (worksheet £0)
- sap_continuous 87.62 → 90.48 (Δ -0.89 → +1.97 — over-correcting
because hot-water cascade is still cascade-£66 vs worksheet £204
including electric shower; HP HW-COP + electric-shower cost are
the next slices).
No golden cert residual shifts (cohort certs don't lodge HP cat 4
or composite cavity+EWI walls).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 0380 (ASHP semi-detached bungalow, worksheet SAP 88.5104)
lodges glazing_type=14 on all windows. The worksheet uses U=1.3258
(post-curtain) for line (27), back-calculating to a raw U=1.40 —
the SAP10.2 Table 24 row for "Double or triple glazed, 2022 or
later" (England/Wales 2022+ / Scotland 2023+ / NI 2022+). Without
code 14 in `_API_GLAZING_TYPE_TO_TRANSMISSION` the cascade falls
back to `u_window`'s default (~U=2.50 post-curtain), inflating
windows HLC by 5 W/K on cert 0380 (6.80 → 11.68).
Added `14: (1.4, 0.72, 0.70)` — same U/g/frame as code 13. Codes
13 and 14 are schema siblings within the post-2022 product family
(the cert lodgement integer differentiates between DG and TG
sealed-unit variants but Table 24 collapses them to the same row).
Effect on cert 0380 API path:
- windows HLC 11.68 → 6.80 (= worksheet 6.80 exact)
- (37) total HLC 104.22 → 99.34 (worksheet 96.09; Δ +3.25 left
on walls — next slice closes it)
- sap_continuous 86.82 → 87.62 (Δ -1.69 → -0.89; closer to
worksheet 88.51)
No golden cert residuals shifted (cohort + 9501 don't lodge
glazing_type=14).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 9501 (top-floor flat + RR + measured PV) is now CLOSED on both
Summary and API paths at 1e-4 vs worksheet 68.5252 (Slices 99a-99e
on Summary + 100a-100c on API). Three boiler certs in total now
have Layer 4 production gates.
Updated handover lists the 7 ASHP workstream (still deferred), the
8 cohort certs without worksheets (residuals tightened by Slice
100c's gap-aware DG-pre-2002 glazing lookup), and captures the 7
key learnings from cert 9501 closure as guidance for the HP
workstream.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two final API gaps to close cert 9501 at 1e-4:
(a) PV array surfacing — third shape variant:
Schema-21 EPCs carry `photovoltaic_supply` as one of three shapes:
- legacy `{"none_or_no_details": {...}}` (PV absent / roof-only)
- nested list `[[{...}], ...]` (cohort cert 2130)
- dict wrapper `{"pv_arrays": [{...}]}` (cert 9501)
The schema's `PhotovoltaicSupply` modelled only `none_or_no_details`
— cert 9501's measured arrays under `pv_arrays` were silently
dropped (Δ -£250 PV credit → -9.32 SAP). Added
`SchemaPhotovoltaicArray` dataclass + `pv_arrays:
Optional[List[...]]` sibling field on `PhotovoltaicSupply`; updated
`_map_schema_21_pv` to dispatch on the new shape.
(b) Gap-aware glazing lookup (RdSAP 10 Table 24 row 2):
DG pre-2002 spec U varies by gap: 6mm=3.1 / 12mm=2.8 / 16+=2.7.
The mapper's flat `_API_GLAZING_TYPE_TO_TRANSMISSION[3]` returned
U=2.8 unconditionally — cert 9501 lodges `glazing_gap="16+"` so
the worksheet uses 2.7. Added `_API_GLAZING_TYPE_GAP_TO_
TRANSMISSION` keyed by (type, gap) with the spec-table values for
code 3; `_api_glazing_transmission` consults the per-gap dict
first, falling back to type-only when no gap entry exists.
Refactored the inline `SapWindow(...)` build into
`_api_sap_window` helper (also nets one pyright error: net-zero
actually improved 33 → 32 on mapper.py).
Effect on cert 9501 API path:
- sap_continuous 59.20 → **68.525161** (= worksheet 68.5252 exact;
Δ -0.000039 — well within 1e-4)
- total_fuel_cost £1101 → £849.21 (= worksheet 849.21 exact)
- pv_export_credit £0 → £250.02 (= worksheet 250.02 exact)
Re-pinned residuals (5 cohort certs with glazing_gap="16+" or 6 now
pick up the spec-correct DG-pre-2002 U):
- 0300: PE +8.44 → +8.28, CO2 -0.23 → -0.25
- 6035: PE +48.30 → +47.85, CO2 +1.10 → +1.09
- 7536: PE -6.51 → -7.08, CO2 -0.17 → -0.19
- 8135: PE -5.31 → -3.66 (gap=6 spec U=3.1), CO2 -0.07 → -0.04
- 2130: PE -38.18 → -38.63, CO2 +0.30 → +0.30
Layer 4 chain test `test_api_9501_full_chain_sap_matches_worksheet
_pdf_exactly` added — third production gate after cert 001479 +
cert 0330. First flat-shaped cert in the production gate set.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`_total_floor_area_from_building_parts` previously summed only
`sap_floor_dimensions[*].total_floor_area`; the RR floor area lives
under `sap_room_in_roof.floor_area` per RdSAP §3.9 convention and
was dropped from the per-bp TFA sum. Cert 9501 (113.08 m² real
TFA, of which 31.8 m² is RR) showed TFA 81.28 on the API path —
the cascade then under-computed occupancy N (Appendix J), HW kWh
(Appendix J), lighting kWh (Appendix L), and internal gains.
Add the RR contribution to the sum. The top-level
`schema.total_floor_area` scalar (integer-rounded for cert 9501:
113 vs raw 113.08) is still the fallback when no per-bp dims are
lodged.
Re-pinned residuals (improvements — TFA now includes the previously-
dropped RR storey):
- 0240: SAP -15 → -14, PE +15.69 → +12.49, CO2 +0.90 → +0.70
- 6035: PE +49.51 → +48.30, CO2 +1.14 → +1.10
Effect on cert 9501 API path: TFA 81.28 → 113.08 (= worksheet
113.08 exact). SAP delta still -9.32 vs worksheet — the remaining
gap is dominated by the missing PV credit (£250 — next slice).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two RR shapes coexist in real-API JSON: cohort certs (6035, 0240,
schema test 21_0_1.json) lodge `room_in_roof_type_1` (RdSAP §3.9.1
Simplified Type 1 — gable lengths only, cascade applies the 2.45 m
default storey height); cert 9501 lodges `room_in_roof_details`
(RdSAP §3.9 Detailed RR — per-surface lengths + heights + flat-
ceiling detail). The schema only modelled the Simplified-Type-1
wrapper, so `from_dict` parsed cert 9501's Detailed-RR block as
None and the API mapper built `SapRoomInRoof` with `detailed_
surfaces=None`. The cascade then defaulted to Simplified Type 2
"all elements" (RR floor area × Table 18 col(4) age-B U=2.30) for
the whole RR → roof HLC 149.43 W/K vs worksheet 18.10 (Δ +131.32).
Changes:
- Add `RoomInRoofDetails` dataclass to both schema 21.0.0 and 21.0.1
with the 10 fields the JSON lodges: gable_wall_type_{1,2} +
gable_wall_length_{1,2} + gable_wall_height_{1,2} + flat_ceiling_
length_1 + flat_ceiling_height_1 + flat_ceiling_insulation_
type_1 + flat_ceiling_insulation_thickness_1. `SapRoomInRoof`
gains a sibling `room_in_roof_details` field next to the legacy
`room_in_roof_type_1`; both shapes are now lossless.
- Extract `_api_build_room_in_roof` mapper helper that reads from
whichever block is present and populates
`SapRoomInRoof.detailed_surfaces` from the Detailed-RR block.
Gables route to `gable_wall_external` for flats (top-floor flats
with RR sit at the end of the building, no neighbour above) and
to `gable_wall` (party at U=0.25) otherwise — mirrors the Summary
mapper's `_map_elmhurst_rir_surface` heuristic.
- Replace both inline `SapRoomInRoof(...)` builds in
`from_rdsap_schema_21_0_0` and `from_rdsap_schema_21_0_1` with
the helper.
Effect on cert 9501 API path:
- roof HLC 149.43 → 18.10 (= worksheet 18.10 exact)
- walls HLC 168.74 → 218.81 (= worksheet 218.81 exact)
- (37) total HLC 382.19 → 297.54 (worksheet 296.68; Δ +0.86)
- sap_continuous still -9.27 vs worksheet because TFA on the API
path is still 81.28 (missing the 31.8 m² RR floor area) — next
slice closes that.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`EpcPropertyData.PhotovoltaicArray.pitch` is the RdSAP 10 §11.1
integer code (1=0°, 2=30°, 3=45°, 4=60°, 5=90°) — NOT degrees. The
cascade's `cert_to_inputs._PV_PITCH_DEG_BY_CODE` reads the code, not
the value. Slice 99d's mapper passed the raw degrees (45) directly,
which fell through to the default 30° lookup (Appendix U3.3 S(SW,
30°) ≈ 1029 kWh/m²/yr vs S(SW, 45°) ≈ 1004 — 2.5% over-credit on
the PV generation, manifesting as -£6.27 over-credit on total cost
→ +0.23 SAP delta).
Added `_elmhurst_pv_pitch_code` helper that maps the lodged degrees
to the nearest tabulated code (snap-to-nearest fallback for non-
tabulated tilts; defaults to code 2 / 30° per the cascade's own
`_PV_PITCH_DEG_DEFAULT`).
Effect on cert 9501 Summary path:
- pv_export_credit £256.30 → £250.02 (= worksheet 250.02 exact)
- total_fuel_cost £842.94 → £849.21 (= worksheet 849.21 exact)
- sap_continuous 68.7577 → **68.5252** (= worksheet 68.5252 exact;
Δ -0.0000 at 1e-4)
`test_summary_9501_full_chain_sap_matches_worksheet_pdf_exactly`
added — the second flat-shaped cert pinned to worksheet SAP at 1e-4
after the cert 0330 / 001479 boiler-house chain tests. Third boiler
validation cert closed.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 9501 lodges measured PV: 2.36 kWp South-West, 45° pitch, "None
Or Little" overshading. The worksheet's §10a credit (-250.02 GBP =
PV used in dwelling £-129.49 + PV exported £-120.53) depends on the
Appendix M / Appendix U3.3 cascade reading these from
`SapEnergySource.photovoltaic_arrays`. The prior extractor only
captured the `photovoltaic_panel: "Panel details"` label — the
actual kW / orientation / elevation / overshading were silently
dropped, so the cascade computed total cost ~£250 too high → ECF
2.92 vs worksheet 2.26 → SAP 59.26 vs 68.53 (Δ -9.27).
Changes:
- Extend `surveys.elmhurst_site_notes.Renewables` with 4 new
optional fields: pv_peak_power_kw / pv_orientation /
pv_elevation_deg / pv_overshading.
- Add `ElmhurstSiteNotesExtractor._extract_pv_array_detail` —
anchors on "Photovoltaic panel details" then reads the 4
consecutive value lines (kWp, orientation, elevation, overshading).
- Add `_elmhurst_pv_arrays` mapper helper to build the
`[PhotovoltaicArray(...)]` list when all 4 values are present;
return None for the "PV absent" path the cascade already handles.
- Add `_ELMHURST_PV_OVERSHADING_TO_RDSAP` map: "None Or Little" → 1
(ZPV=1.0 per cert_to_inputs._PV_OVERSHADING_FACTOR), "Modest" →
2, "Significant" → 3, "Heavy" → 4. RdSAP omits SAP10.2 Table M1's
5th "Severe" bucket.
- Wire `photovoltaic_arrays=_elmhurst_pv_arrays(survey.renewables)`
into `from_elmhurst_site_notes`'s `SapEnergySource(...)` call.
Effect on cert 9501 Summary path:
- sap_continuous 59.2585 → 68.7577 (target 68.5252; Δ +0.23)
- total_fuel_cost £1099 → £843 (worksheet £849; -£6 over-credit)
- ECF 2.92 → 2.24 (worksheet 2.26; -0.02 over-credit)
The remaining +0.23 SAP / +£6 cost drift is a precision gap in the
Appendix M cost-offset cascade for measured PV (not a missing-data
gap); next slice closes it to 1e-4.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 9501 worksheet line (29a) lodges both RR gable walls (13.50 +
15.95 m²) as EXTERNAL walls at U=1.7 (the main-wall U for age B
Solid Brick), contributing +50.07 W/K on top of the 168.74 W/K main-
wall HLC for a (29a) total of 218.81 W/K. Two mapper gaps blocked
this:
1. The Summary mapper defaulted un-typed RR gable walls
(`surface.gable_type=None`) to `gable_wall` (party, U=0.25 per
RdSAP Table 4 row 2). For flats with RR — top-floor dwellings
that sit at the end of a building block with no neighbour above
— the gable walls are exposed external, not party. Threading
`is_flat=property_type.lower()=='flat'` through
`_map_elmhurst_building_parts` → `_map_elmhurst_room_in_roof` →
`_map_elmhurst_rir_surface` switches the default for un-typed
gables on flats to `gable_wall_external` (cascade falls through
to main-wall U `uw`).
2. The Elmhurst wall-construction code map was missing "SO Solid
Brick" (newer Elmhurst PDF variant; the cohort certs lodge "SB
Solid Brick"). Cert 9501's main wall fell through to
wall_construction=None → cascade uw=1.5 (Table-18 unknown-cons
age-B default) instead of 1.7 (Table-18 solid-brick age-B).
Added "SO": 3 alongside "SB": 3 — same SAP10 mapping.
Joint effect on cert 9501 Summary path:
- walls HLC 148.89 → 218.81 (exact worksheet match)
- party_walls HLC 7.36 → 0.00 (gables no longer route to party)
- (37) total HLC 229.71 → 296.68 (exact worksheet match)
Cohort regression check: 259/0 mapper-chain + extractor + golden
tests pass. Houses keep the historical un-typed-gable → party
default. Houses lodging "SO" instead of "SB" now also pick up the
correct solid-brick U-value.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
For flats, `EpcPropertyData.dwelling_type` needs a "Top-floor" /
"Mid-floor" / "Ground-floor" prefix so the cascade's
`_dwelling_exposure` (cert_to_inputs.py) gates floor + roof party-
surface routing correctly per RdSAP 10 §5. Before Slice 99a, the
broken `built_form` ("2.0 Number of Storeys:") meant cert 9501's
`dwelling_type` was "2.0 Number of Storeys: flat" — never matched
any flat-prefix in the cascade, so the cert was treated as a fully-
exposed dwelling (worksheet had floor U=0 / party-ceiling-down, but
cascade routed both as exposed → Δ +9.25 W/K on floor alone). After
99a's empty-attachment fix the prefix was just " flat" — still no
match.
Slice 99b composes the position prefix from the Summary's lodged
floor location + RR presence:
- floor.location lodges "dwelling below" → floor is party
- + RR present → Top-floor (roof exposed)
- + no RR → Mid-floor (roof party)
- floor.location doesn't lodge dwelling below → Ground-floor
For cert 9501: floor.location="A Another dwelling below" + RR
present (cert lodges Room-in-Roof with gable walls + flat ceiling).
Resulting `dwelling_type` = "Top-floor flat" — matches the cascade's
`_dwelling_exposure` "top-floor" prefix → has_exposed_floor=False,
has_exposed_roof=True, the worksheet's exposure shape.
Houses keep the historical contract: `f"{built_form}
{property_type.lower()}"` — cohort hand-builts and the 2 boiler
chain tests (001479 + 0330) unchanged.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 9501 (Summary_000784.pdf) is a flat. The Elmhurst Summary's
§1.0 "Property type" section lodges the built-form descriptor
("M Mid-Terrace", "D Detached", ...) only for houses — flats have no
attachment line, and the §2.0 "Number of Storeys" header follows
immediately after the "F Flat" property-type value.
The extractor's prior `_extract_attachment` regex captured the line
right after the property-type value unconditionally, so cert 9501
ended up with `attachment="2.0 Number of Storeys:"` — section-header
noise that the mapper surfaced on `EpcPropertyData.built_form`.
Downstream, this broke the cascade's `_dwelling_exposure` routing
(no prefix match → defaulted to fully-exposed houses) and so the
cert 9501 Summary path was Δ -5.25 SAP vs worksheet 68.5252.
Detect section-header noise via the leading `<digit>.<digit> `
pattern and the "Number of Storeys" substring; return "" in that
case so flats produce empty `built_form`. Houses still pick up their
real attachment (cohort 0330's "M Mid-Terrace" remains correct).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Captures session state after cert 0330 closed both Summary and API
Layer 4 1e-4 gates (Slices 96-98). Cert 9501 fixtures are staged
(commit 5d1778ac) but the Summary path is RED at Δ -5.25 SAP because
the cert is a flat with RR + party-floor / party-ceiling — a
fundamentally different cascade shape from the boiler houses we've
validated.
Handover quantifies the cascade-component gaps (-69.92 W/K on walls
because RR gables aren't surfaced, +9.25 W/K on floor because the
party-floor exposure isn't recognised, +7.36 W/K on party walls
because U_party=0 isn't being applied), lists the 4 fixes likely
needed in slice order, and leaves the heat-pump workstream sketch
intact for when the user gives the go-ahead.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
API JSON + Summary PDF for cert 9501-3059-8202-7356-0204. RR/Mid-
terrace flat, 4 building storeys, TFA 113.08 m², mains gas boiler
(PCDB idx 19007), age band B. Worksheet target unrounded SAP
**68.5252**.
Second boiler cert per the per-cert mapper validation workflow:
Summary path proves itself against the worksheet (Layer 2 1e-4 pin),
then the API path catches up (Layer 4 1e-4 pin) — mirrors the cert
0330 cycle.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the cert 0330 API path Layer 4 gate (Δ -0.000011 vs worksheet
SAP 61.5993) by surfacing two previously-broken inputs to the HW
cascade plus aligning the wall-net-deduction with the worksheet's
2-d.p.-per-window rounding convention.
(a) RdSAP schema 21.0.x `shower_outlets` shape mismatch:
real-API certs lodge `[{"shower_outlet_type": N, "shower_wwhrs":
M}, ...]` (a list of bare ShowerOutlet dicts), but the schema
modelled it as `[ShowerOutlets]` with nested
`{"shower_outlet": {...}}` wrappers. `from_dict` silently dropped
every bare element's payload (left `shower_outlet=None`),
blanking the cascade's mixer/electric counts on cert 0330 (and 4
other golden fixtures). Normalisation in `from_api_response`
rewrites the bare list shape to the wrapped form before
`from_dict` parses, so the schema's `ShowerOutlets` dataclass
sees the data it expects — no schema-class breakage downstream.
New helper `_count_shower_outlets_by_type` walks the normalised
list and counts outlets by integer code:
- code 1 → mixer (drives `mixer_shower_count`)
- code 2 → electric (drives `electric_shower_count`)
Empirically derived from the golden cohort + Summary mapper
cross-check (cert 0330 lodges code 2 + Summary surfaces "Electric
shower"; cert 0240 lodges multiple code-1 outlets on a
conventional oil-boiler + cylinder dwelling). No spec page
reference found.
Wired into both `from_rdsap_schema_21_0_0` and
`from_rdsap_schema_21_0_1`. Effect on cert 0330 API path:
`mixer_shower_count` 1 (cascade default) → 0; `electric_shower_
count` None (= 0) → 1; HW kWh 3172.65 → 2111.93. SAP Δ +2.1155
→ -0.0012.
(b) Per-window 2-d.p. area rounding in wall-net deduction:
RdSAP 10 §15 rounds per-window area at 2 d.p. before any sum.
The cascade's `windows_w_per_k_total` branch already rounds
per-window for the curtain transform; the wall-net deduction
branch (computing `gross_wall - windows - door` for the (29a)
line) was rounding the SUM once, which for cert 0330's 9 Main
windows yields 12.22 m² vs the worksheet's per-window-rounded
12.23 m² — Δ +0.01 m² × U=1.5 = +0.015 W/K on (29a). Aligned
both branches to round per-window, matching worksheet line (27).
SAP Δ -0.0012 → -0.000011.
Layer 4 chain test added:
- `test_api_0330_full_chain_sap_matches_worksheet_pdf_exactly` pins
cert 0330 API path SAP at 1e-4 vs worksheet 61.5993. This is the
second boiler validation cert with a Layer 4 1e-4 gate (cert
001479 is the first).
Re-pinned golden cert residuals (shifted by changes (a) and (b)):
- 0300: PE +7.52 → +8.44, CO2 -0.27 → -0.23 (Slice 98a — electric
shower count surfaced; cert has 1 electric + 1 mixer outlets)
- 2130: PE -38.17 → -38.18, CO2 +0.305 → +0.304 (Slice 98b —
window rounding edge)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 0330 API path was at Δ +1.68 SAP after Slice 96 because all 11
windows (`sap_windows[*].glazing_type = 2`) fell through
`_API_GLAZING_TYPE_TO_TRANSMISSION` (which only covered codes 3 +
13) to the cascade's `u_window` default (~U=2.5). The cert's actual
glazing is "Double, England/Wales 2002 or later (before 2022)" per
RdSAP 10 Table 24 page 79 → U=2.0, g=0.72 (PVC/wooden frame).
RdSAP 10 Table 24 verbatim:
Glazing Installed Gap U-value g
Double or England/Wales: 2002 or later 2.0 0.72
triple Scotland: 2003 or later any
glazed N. Ireland: 2006 or later
The cascade's curtain-transform path (`U_eff = 1/(1/U + 0.04)`)
takes U_raw=2.0 to U_eff=1.8519 — matching the worksheet's per-
window (27) U value column to 4 d.p. across all 11 windows.
Effect on cert 0330 API path:
- Windows HLC 36.4545 → 29.7407 (= worksheet exact)
- (37) total fabric heat loss 244.48 → 237.77 (≈ worksheet 237.75)
- SAP Δ +1.68 → +2.12 (windows fix unmasks the standalone HW gap,
which the next slice closes)
Re-pinned residuals (5 affected golden certs):
- 0240: PE +17.85 → +15.69; CO2 +1.01 → +0.90; SAP unchanged at -15
- 0300: PE +7.76 → +7.52; CO2 -0.25 → -0.27; SAP unchanged at +0
- 0390-2954: PE -26.46 → -28.68; CO2 -2.56 → -2.76; SAP unchanged
- 7536: SAP +0 → +1; PE -3.45 → -6.51; CO2 -0.09 → -0.17
- 8135: PE -2.41 → -5.31; CO2 -0.02 → -0.07; SAP unchanged at +0
The PE/CO2 widening on some certs (vs lodged GOV.UK values) reflects
the cascade now using the spec table U=2.0 where those certs may have
lodged a higher project-specific U — the spec-table is the right
floor for the API path; per-window measured U overrides would belong
on the cert's window_transmission_details.u_value field, which the
API JSON doesn't surface uniformly.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 0330 (mid-terrace boiler, Summary_000897.pdf) Summary path was at
Δ +0.4667 SAP vs worksheet 61.5993 because Ext1's flat roof fell through
`_ROOF_BY_AGE` (Table 18 column (1), pitched-roof "between joists"
defaults) to 0.40 W/m²K for age D — the spec value is 2.30 W/m²K from
column (3) "Flat roof" (RdSAP 10 spec page 45).
RdSAP 10 §5.11 Table 18 column (3) verbatim:
Age A,B,C,D → 2.30; E → 1.50; F → 0.68; G → 0.40; H,I → 0.35;
J,K → 0.25; L → 0.18; M → 0.15.
Footnote (a): "If the roof insulation is 'none' use U = 2.3 (all roof
types, except for thatched roofs)" — confirms the col-3 entries for
old ages are the uninsulated row, applied because cert 0330's Ext1
lodges "Flat" construction with no measured insulation thickness.
Changes:
- `_FLAT_ROOF_BY_AGE` added in rdsap_uvalues.py
- `u_roof` gains `is_flat_roof: bool = False` parameter
- `heat_transmission_from_cert` detects flat roofs from
`part.roof_construction_type` ("flat" substring) and routes through
the new column.
Effect on baseline:
- cert 0330 Summary chain test: RED Δ+0.4667 → GREEN at 1e-4 (worksheet
total fabric heat loss 237.7549 W/K matches cascade to 4 d.p.)
- cert 001479 Layer 4 chain test: unchanged (Main pitched, no flat
components)
- cohort certs 000477/000516: unchanged (no flat roofs)
- golden cert 0300-2747-7640-2526-2135: SAP residual +1 → 0 (improved),
Ext1 is genuinely flat; pe/co2 residuals re-pinned. The dwelling has
the same Main-pitched + Ext1-flat shape as cert 0330; same fix.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds the (API JSON + Summary PDF) fixtures for cert
0380-2471-3250-2596-8761 — the Air Source Heat Pump pilot
identified in the handover. Property: 16 Beech Lea, WIGTON CA7 5JY
(semi-detached bungalow, ASHP PCDB idx 104568).
Source: API JSON fetched via EpcClientService. Summary PDF copied
from `sap worksheets/Additional data with api/
0380-2471-3250-2596-8761/Summary_000899.pdf`.
Worksheet target: SAP 88.5104 (continuous), from `dr87-0001-000899
.pdf`.
**This is the HP pilot, intentionally deferred.** Initial probe on
these fixtures (uncommitted before this slice):
- Summary mapper cascade SAP: 18.08 (Δ -70.43 vs worksheet)
- API mapper cascade SAP: 70.14 (Δ -18.37 vs worksheet)
Both paths are catastrophically RED. The mapper has never been
validated against an ASHP cert and there's substantial cascade
plumbing required:
- API mapper correctly identifies the HP (COP 2.3) but fabric HLC
is 104 W/K vs the ~50 W/K needed for SAP 88.51.
- Summary mapper misreads the HP as an 80%-efficient boiler
(catastrophic).
- 7 of 9 newly-staged certs are ASHPs (6 share PCDB idx 104568,
cert 9418 uses 102421), so a shared HP-cascade fix will likely
close most of them at once.
Stashed here so the next agent can pick up the HP workstream
without needing to refetch from the EPB API. Recommend not
attempting these slices until the boiler workflow (cert 0330) is
proven; the boiler cascade is the reference shape and HP work
should build on a known-good baseline. Handover §"Heat-pump
workstream sketch" outlines the likely 15-30 slice queue.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds the (API JSON + Summary PDF) fixtures for cert
0330-2249-8150-2326-4121 — the boiler pilot identified in the
handover. Property: 17 Summerfield Road, MANCHESTER M22 1AE
(mid-terrace house, mains gas boiler PCDB idx 10241, age D).
Source: API JSON fetched via EpcClientService from
https://api.get-energy-performance-data.communities.gov.uk
(OPEN_EPC_API_TOKEN). Summary PDF copied from
`sap worksheets/Additional data with api/0330-2249-8150-2326-4121/
Summary_000897.pdf` (where the user provided the triple).
Worksheet target: SAP 61.5993 (continuous), from `dr87-0001-000897
.pdf` in the same source directory.
Current state on these fixtures (uncommitted before this slice):
- Summary mapper cascade SAP: 62.0660 (Δ +0.4667 vs worksheet)
- API mapper cascade SAP: 63.7446 (Δ +2.1453 vs worksheet)
Both paths RED at 1e-4. Two specific cascade-component gaps
identified in the handover for follow-up slices:
1. Windows HLC +6.71 W/K (API vs Summary) — likely glazing_type=14
not in Slice 93's `_API_GLAZING_TYPE_TO_TRANSMISSION` (only
codes 3 and 13 mapped).
2. HW kWh +1060 (API 3172.65 vs Summary 2112.00) — §4 subsystem
gap; needs occupancy/shower/cylinder probe.
This commit stages the fixtures only — no tests added yet. The
follow-up slice should add a RED Layer 2 test (Summary path 1e-4
vs 61.5993) and proceed slice-by-slice.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Rewrites the cert 001479 closure handover into a forward-looking
brief for the new workstream: validating the API EpcPropertyDataMapper
against 9 newly-staged (Summary + worksheet + API) cert triples.
Key contents:
- User's stated workflow (verbatim): Summary path proves itself
against the worksheet → becomes canonical reference for API parity.
- Folder-structure changes since the prior handover were written
(packages/domain/ removed; sap10_calculator + sap10_ml now at the
repo root under a PEP 420 namespace; docs/sap-spec/ moved into
domain/sap10_calculator/docs/; PCDB data into tables/pcdb/data/).
- New test data layout: `sap worksheets/Additional data with api/
<cert-ref>/{Summary_NNNNNN.pdf, dr87-0001-NNNNNN.pdf}`.
- Cert reference table with heating type, PCDB index, worksheet SAP,
TFA, bp count, dwelling type for all 9 triples.
- Major scope discovery: 7 of 9 are Air Source Heat Pumps (PCDB
104568 / 102421). The mapper has never been validated against HPs;
cert 0380 pilot showed catastrophic deltas (Summary -70 / API -18
SAP vs worksheet). Recommended deferring HP certs until boiler
workflow is proven.
- Cert 0330 (mid-terrace gas boiler) pilot status: fixtures staged
uncommitted; Summary path +0.47 SAP, API path +2.15 SAP vs
worksheet 61.5993. Cascade-component diff localises 2 specific
gaps (windows HLC +6.71 W/K likely from glazing_type=14 missing
from Slice 93's transmission map; HW kWh +1060 needs §4
subsystem probe).
- Tooling shortcut: use OPEN_EPC_API_TOKEN (not EPC_AUTH_TOKEN) in
backend/.env with EpcClientService._fetch_certificate(cert_ref)
to fetch raw JSON.
- First actions for next agent: confirm baseline, commit cert 0330
fixtures, add RED Layer 2 test, iterate.
Lesson preserved: cohort hand-builts encode non-spec quirks
(e.g. has_suspended_timber_floor=False to override §(12) spec
inference and match the non-spec worksheet). Cross-check against
spec-inferred mapper output before trusting hand-built fields.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Orientation for the next chat picking up the two open fronts after the
ara_first_run rebuild shipped:
- where things stand (merged to main via per-cert; branch/worktree layout;
PRs into per-cert), authoritative ADRs/CONTEXT to read,
- current architecture + key files (post baseline→property_baseline /
FirstRun→AraFirstRun rename),
- conventions + gotchas (TDD, ephemeral PG, FakeUnitOfWork, pyright noise to
ignore, gh-credential push workaround),
- Task 1: wire Sap10Calculator into PropertyBaselineOrchestrator (Calculated
SAP10 Performance as a third value-set; failure-posture decision),
- Task 2: Modelling (stubs to build out; MaterialsRepository naming open;
needs a UoW when writing Plans),
- the raising/no-op seams not to mistake for done,
- known doc drift flagged (CONTEXT term vs PropertyBaselinePerformance class;
stale domain/sap/ path → domain/sap10_calculator).
Also banners ara_backend_design.md as superseded (architecture) by ADR-0011/0012.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
