Three load-bearing files that the post-Slice-95 tests and docs cite
but were never tracked:
1. `packages/domain/src/domain/sap/rdsap/tests/fixtures/golden/
0535-9020-6509-0821-6222.json` — API JSON for cert 001479
(Elmhurst worksheet P960-0001-001479, lodged 31 Oct 2025).
Required by `test_api_001479_full_chain_sap_matches_worksheet_pdf_
exactly` (Slice 95's Layer 4 1e-4 gate) and by
`test_golden_cert_residual_matches_pin` (residual-from-integer
pin path). Without this committed, both tests fail to find the
fixture file.
2. `docs/sap-spec/RdSAP 10 Specification 10-06-2025.pdf` — replaces
the previously-tracked `rdsap-10-specification-2025-06-10.pdf`
(same content, cleaner filename). Cited from 5 source files
(`table_32.py`, `pcdb/parser.py`, README.md, SAP_CALCULATOR.md,
NEXT_AGENT_PROMPT.md) and every spec-citation commit message
in Slices 87-95. Git auto-detected the rename.
3. `docs/sap-spec/PCDF_Spec_Rev-06b_12_May_2021.pdf` — cited from
`pcdb/parser.py:69` and the §4-water-heating combi-loss
docstrings; needed to validate the PCDB Table 3a/3b/3c routing
logic.
Also fixes the one stale reference in `test_dimensions.py:471`
that still pointed to the old `rdsap-10-specification-2025-06-10
.pdf` filename — now points to the renamed file.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Status: Slice 95 closed Layer 4 (API → cascade SAP) on cert 001479 at
< 1e-4 vs worksheet 69.0094. Production goal MET; the
`test_api_001479_full_chain_sap_matches_worksheet_pdf_exactly` test
formalises this gate. Updates to keep the next agent honest:
- NEXT_AGENT_PROMPT: header + status table + cumulative SAP delta table
+ "First action" + epilogue all reflect Slice 95's close-out.
- NEXT_AGENT_PROMPT §4 (Outlier golden cert investigations): rewrote
the cert 0240 entry. The earlier "Type-1 RR gable_wall_lengths not
extracted" claim is stale — mapper.py:1349-1369 already extracts
them (Slices 71-86). The -15 SAP residual is a mix, dominated by
the windows subsystem (11 windows × 18.28 m² with default U≈2.27
because Slice 93's `_API_GLAZING_TYPE_TO_TRANSMISSION` only covers
glazing codes 3 and 13; cert 0240 lodges code 2). Surfacing
glazing_type=2 (and likely other unmapped codes) is the biggest
single-slice leverage point — and would touch 6035 too.
- test_golden_fixtures.py cert 0240 `notes:` field: replaced the
stale RR hypothesis with the actual cascade subsystem breakdown
and the glazing_type-2 surfacing recommendation.
No production code changed; docs and a `_GoldenExpectation.notes`
string only. test_golden_fixtures.py stays GREEN (14 passed).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The end-to-end production cascade `from_api_response → cert_to_inputs →
calculate_sap_from_inputs` now hits cert 001479's worksheet continuous
SAP 69.0094 at abs < 1e-4 (was +0.000584). Two fixes:
1. API mapper: `from_rdsap_schema_21_0_{0,1}` computes `total_floor_
area_m2` as Σ per-bp `sap_floor_dimensions[*].total_floor_area.value`
(cert 001479: 30.45+30.77+5.37+1.92 = 68.51), not the lodged scalar
(rounded integer 69). `water_heating_from_cert` reads `epc.total_
floor_area_m2` directly for occupancy N (Appendix J), which propagates
to HW kWh (+6.31 → ~0), Appendix L lighting (+0.98 → 0), and internal
gains (+25.72 W·months → 0).
2. Cascade window area rounding per RdSAP 10 §15 "Rounding of data"
(p.66): "All element areas (gross) including window areas: 2 d.p."
`solar_gains.py` and `internal_gains.py` now round `w * h` to 2 d.p.
to match the existing `heat_transmission.py` pattern (line 344).
Closes the residual solar gains delta (+1.50 W·months → 0) that
became dominant once TFA was fixed.
Re-pinned 5 golden cert residuals where TFA + area rounding shifted
output: 0240 (SAP -14→-15, PE +14.6650→+17.8450, CO2 +0.8060→+1.0097),
6035 (PE +48.2971→+49.5139, CO2 +1.1016→+1.1423), 8135 (PE -2.4194→
-2.4072, CO2 -0.0198→-0.0195), 2130 (PE -38.1521→-38.1666), 0390
(PE +1.6837→+1.6962, CO2 +0.0637→+0.0639).
New test: `test_api_001479_full_chain_sap_matches_worksheet_pdf_
exactly` formalises Layer 4 of the validation stack as a 1e-4 gate.
Pyright net-zero (mapper.py 33).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 001479 API path closed from +3.08 → +0.0006 SAP delta vs
worksheet 69.0094 in Slices 87-94. Fabric heat loss is now EXACT
across all 6 components. Replaced the prior handover (which assumed
the Elmhurst path was still RED with a 0.26 SAP gap on cohort 000474)
with the current state:
- Acceptance criterion corrected: 1e-4 against worksheet continuous
SAP (not ±0.5 against API integer) when a worksheet is available.
- Validation layer status table reflects current GREEN/RED state.
- Slice 87-94 progression captured with each fix's SAP delta impact.
- Diagnostic probe + queue documented for next agent: close 001479's
residual +0.0006 (HW + gains), write Layer 3 diff test, then
process new cert pairs as user sources them.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two API mapper gaps surfacing the cert 001479 +1.18 SAP gap post
Slice 93:
(1) `SapVentilation.sheltered_sides` from API `built_form`
The API schema doesn't lodge sheltered_sides as a discrete field —
it's derived per RdSAP §S5 from the dwelling's built_form. The
cascade defaults to 2 when missing (right for Mid-Terrace) but wrong
for detached/semi/end-terrace. Cert 001479 (built_form=2 Semi-
Detached) needs 1 sheltered side; default 2 over-counted shelter
factor → line (21) under by 0.185 → ventilation under by ~2 ACH/yr.
New `_api_sheltered_sides` translator + `_API_BUILT_FORM_TO_
SHELTERED_SIDES` table (1=Detached/0, 2=Semi/1, 3=End-T/1, 4=Mid-T/2,
5=Encl-End/2, 6=Encl-Mid/3) — mirrors the cohort Elmhurst
`_ELMHURST_SHELTERED_SIDES_BY_BUILT_FORM` keyed by the API integer
enum.
(2) `SapBuildingPart.floor_type` from API `floor_heat_loss`
The Slice 87 spec rule for §2(12) suspended-timber-floor infiltration
(`_has_suspended_timber_floor_per_spec` in cert_to_inputs) requires
the Main bp's lowest floor to have `floor_type == "Ground floor"` to
apply the (12)=0.2/0.1 rule. The API mapper wasn't surfacing this
string (only floor_construction_type), so the spec rule short-
circuited to False even for genuine ground floors and the cascade's
line (12) was 0.0 instead of 0.2.
New `_api_floor_type_str` translator + `_API_FLOOR_HEAT_LOSS_TO_
FLOOR_TYPE` table (1="To external air" for cantilevered exposed
floors, 7="Ground floor"). Routes correctly for cert 001479: Main +
Ext1 carry floor_heat_loss=7 → both Ground floor; Ext2 carries
floor_heat_loss=1 → exposed (its is_exposed_floor=True already lifts
the floor U cascade to Table 20).
**Result on cert 001479 API path:**
SAP delta: +1.18 → +0.0006 (essentially exact match at integer SAP)
Cascade SAP=69.0100 vs worksheet 69.0094 — within 1e-3 of target.
The remaining ~0.001 SAP gap is dominated by:
- hot_water_kwh_per_yr: +6.7 (API 2365.0 vs target 2358.3)
- internal_gains Σ: +25.7 W·months (subtle gain-cascade differences)
- solar_gains Σ: +1.5 W·months
Sub-1e-3 SAP impact each; would need slice-by-slice diagnosis to
close to the strict 1e-4 bar.
Layer 3 API-mapper-vs-Summary-mapper EpcPropertyData equivalence:
the API path now produces SAP within 0.001 of the Summary path
(Summary Layer 2 = 69.0094 EXACT). API integer SAP = 69 = worksheet
integer SAP = 69 ✓ — matches the API's published energy_rating_
current=69 (zero residual on the production goal metric).
Golden cert residuals: 8 of 10 expectations shifted by Slices 90-94
cascade improvements. Spec-compliance shifts; new residuals pinned.
Pyright: mapper.py 33 → 33.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The API schema lodges `glazing_type` (int code) per window but
`window_transmission_details=None` and `frame_factor=None`. Without
per-window U lodgement the cascade falls back to a single global
`u_window(None,None,None)=2.5` × total area, which over-shot cert
001479's window W/K by +2.63 (cascade 46.23 vs worksheet 43.60).
Fix: `_API_GLAZING_TYPE_TO_TRANSMISSION` lookup translates
`glazing_type` → (u_value, solar_transmittance, frame_factor) and
the mapper populates `WindowTransmissionDetails` + `frame_factor`
per window so the cascade uses its per-window U fast path (each
window contributes A × U_eff_individual rather than total_area ×
U_eff_global). Two codes mapped now:
3 → DG pre-2002 U=2.8 g=0.76 FF=0.70
13 → DG post-2022 Argon U=1.4 g=0.72 FF=0.70
Cert 001479 lodges 8 Main windows at glazing_type=3 + 1 Ext1 window
at glazing_type=13 — exactly the manufacturer-lodged worksheet
values. The cascade now matches the worksheet's
`Windows 1: 13.96 × 2.518 = 35.15 W/K` and
`Windows 2: 6.37 × 1.3258 = 8.45 W/K` → **windows W/K EXACT 43.5962**.
**Cert 001479 API path: fabric heat loss is now COMPLETELY EXACT
across all 6 components** (walls/party/roof/floor/windows/doors all
match worksheet at the worksheet's 4 d.p. precision).
Total fabric: 139.4957 W/K ✓ (was 122.6130 before Slice 87)
walls: 39.7652 ✓
party walls: 17.0700 ✓
roof: 10.3438 ✓
floor: 23.1705 ✓
windows: 43.5962 ✓
doors: 5.5500 ✓
API SAP delta progression through Slices 87-93:
Slice 87 baseline: +3.0752
After Slice 90: +1.5298 (party walls)
After Slice 91: +1.0970 (descriptive strings + roof desc)
After Slice 92: +1.0022 (floor dims)
After Slice 93: +1.1846 (windows — fabric now EXACT)
The +1.18 SAP gap is now PURELY non-fabric: candidates are internal
gains, solar gains, ventilation, MIT, or hot water cascade — to
diagnose in the next slice.
Golden cert residuals updated for the cascade improvements. Pyright
net-zero on mapper.py (33 → 33).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Three coupled API-mapper fixes that close the cert 001479 floor-W/K
gap from +4.39 to EXACT 0.
(1) Upper-floor room_height_m += 0.25 m
SAP 10.2 convention: every storey above the lowest adds 0.25 m to the
lodged room_height for the joist/floor-void contribution (cohort
Elmhurst mapper already applies this via `_UPPER_FLOOR_HEIGHT_ADD_M`
at line 2338). The API schema lodges the raw internal height; the
cascade volume computation needs the +0.25 m before computing party-
wall area and ventilation ACH. For cert 001479 Main floor=1, raw
lodge 2.28 m vs worksheet 2.53 m — without the fix, party W/K was
short by 0.87 (party_wall_length × delta_height × U).
(2) `is_exposed_floor=True` when `bp.floor_heat_loss == 1`
API integer code 1 on `floor_heat_loss` signals an exposed floor (a
bp's lowest storey hanging over an unheated space or external air).
Mirrors the cohort Elmhurst mapper's `_is_floor_exposed_to_unheated_
space` for the API path. Applied only to the lowest storey (floor==0)
per the cohort 000490/000487 fixture convention. For cert 001479
Ext2 (cantilevered upper-storey extension over external air), this
routes the cascade through Table 20's `u_exposed_floor` (U=1.20)
rather than the BS EN ISO 13370 ground-floor formula.
(3) `floor_insulation_thickness="NI" → None` for cascade default
API certs commonly lodge "NI" (no measured thickness) on floors that
aren't actually uninsulated — for newer age bands (I-M with non-zero
Table 19 defaults: 25/75/100/100/140 mm) the cascade should use the
age-band default insulation rather than treating "NI" as explicit
zero. Translate "NI" → None at the mapper boundary so `u_floor`
reaches the Table 19 fallback. For cert 001479 Ext1 (age M, suspended
timber, NI lodged) the cascade now returns U=0.20 via the age-M
140 mm default — previously gave U=1.05 from treating thickness as 0.
**Floor W/K is now EXACT for cert 001479** (23.1705 ✓).
Impact on cert 001479 API path:
Before Slice 87: +3.0752 SAP delta
After Slice 90: +1.5298
After Slice 91: +1.0970
After Slice 92: +1.0022 (floor W/K exact; remaining gap is in
windows / gains — Slice 93)
Golden cert residual updates: 7 of 10 expectations shifted from the
floor cascade improvements (NI→None changed many certs with age I-M
extensions). Spec-compliance shifts; new residuals committed.
Pyright: mapper.py 33 → 33.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Three tightly-coupled fixes that close another big chunk of cert
001479's API-path SAP gap.
(1) Surface human-readable strings on SapBuildingPart from API ints
The API mapper sets `bp.floor_construction_type` and `bp.roof_
construction_type` strings via int→string lookups so the cascade
fixes from Slices 88 + 89 also apply to the API path:
- `_API_FLOOR_CONSTRUCTION_TO_STR`: 1=Solid, 2=Suspended timber
(drives `u_floor`'s suspended-branch selection)
- `_API_ROOF_CONSTRUCTION_TO_STR`: 1=Flat, 3=Pitched no-loft,
4=Pitched-access-to-loft, 5=Vaulted, 8=Pitched-sloping-ceiling
(drives the cos(30°) inclined-surface factor)
(2) Pre-1950 PS sloping ceiling → thickness=0 (port Slice 57)
`_api_resolve_sloping_ceiling_thickness` mirrors Slice 57's Elmhurst-
mapper logic: when a PS pitched-sloping-ceiling roof (API code 8)
carries no insulation thickness on a pre-1950 dwelling (age bands
A-D), set thickness=0 so the cascade returns the uninsulated U=2.30
rather than the age-band-default (e.g. U=0.40 for age C).
(3) Cascade: per-bp `roof_thickness=0` overrides global "insulated"
description
For cert 001479 the API's `epc.roofs` carries two descriptions
(Main's "Pitched, 300mm loft insulation" + Ext1's "Pitched,
insulated") which the cascade joined into a global
`roof_description`. `u_roof`'s Table 18 footnote (2) ("assumed
insulation if described as insulated") then incorrectly upgraded
Ext2's explicitly-uninsulated thickness=0 to ins_mm=50 → U=0.68
instead of 2.30. Fix: in `heat_transmission.py` per-bp roof loop,
drop `roof_description` when the per-bp `roof_thickness` is
explicitly 0. The per-bp thickness lodgement is the authoritative
signal; the global description is for cases where no thickness was
lodged at all.
Impact on cert 001479 API path (cumulative through Slice 91):
Before Slice 87: +3.0752 SAP delta
After Slice 90: +1.5298 (party wall enum fix)
After Slice 91: +1.0970 (descriptive strings + roof desc fix)
Roof W/K is now EXACT for cert 001479 (10.3438 = worksheet target).
Golden cert residual updates: 8 of 10 expectations shifted by
Slices 87-91 cascade improvements:
0240: SAP -10→-13, PE -2.05→+10.45, CO2 -0.04→+0.59
6035: SAP -4→ -5, PE +34.02→+34.50, CO2 +0.76→+0.77
7536: SAP +3→ +2, PE -22.53→-15.83, CO2 -0.60→-0.42
8135: SAP unchanged, PE -16.51→-16.37, CO2 unchanged
2130: SAP unchanged, PE -51.90→-51.10, CO2 +0.14→+0.15
0240/6035/7536: spec-compliance shifts (more accurate U-values
move further from the assessor's lodged SAP, because the
assessor's SAP was itself produced with the same incorrect
paths the cascade previously matched).
Pyright: mapper.py 33 → 33; heat_transmission.py 13 → 13;
test_golden_fixtures.py 0 → 0.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The GOV.UK API `party_wall_construction` field uses a different enum
from the regular `wall_construction` field — RdSAP 10 Table 15 (p.31
"U-values of party walls") defines 5 categories that the API encodes
as integer codes 0..5 plus a "NA" string for extensions without a
party wall. The cascade's `u_party_wall` consumes the SAP10
`wall_construction` enum directly, so passing the raw API code gave
wildly wrong U-values (API code 2 = "Cavity masonry unfilled" →
should produce U=0.5, but cascade interpreted code 2 as SAP10
WALL_STONE_SANDSTONE → 0.0 W/m²K).
Impact on cert 001479 (the only golden fixture with party=2 lodged):
Before: party_walls = 0.00 W/K (cascade applied U=0.0)
After: party_walls = 16.21 W/K (cascade applies U=0.5)
API mapper → cascade SAP delta:
Before Slice 90: +3.0752
After Slice 90: +1.5298
The remaining party-wall shortfall (16.21 vs target 17.07 W/K, -0.87
W/K) is the room_height_m +0.25 SAP convention not yet applied to
the API path — Slice 92 will close that.
Translation table (per `_API_PARTY_WALL_CONSTRUCTION_TO_SAP10`):
0 → None (no party wall present; party_wall_length=0 anyway)
1 → SAP10 code 3 (Solid Brick) → u_party_wall = 0.0
2 → SAP10 code 4 (Cavity) → u_party_wall = 0.5
3 → SAP10 code 4 (Cavity) → cascade emits 0.5 (TODO: 0.2 for
cavity filled needs cascade extension)
4 → None (Unable, house) → u_party_wall default 0.25
5 → None (Unable, flat) → TODO: spec says 0.0 for flats
Schema change: `SapBuildingPart.party_wall_construction` is now
`Optional[Union[int, str]]` (was `Union[int, str]`) — the "0 sentinel
for Unable" convention was already in cohort hand-builts but the type
forbade the cleaner `None` representation. To preserve the dataclass
"no-default after default" rule, `sap_floor_dimensions` gets a
`field(default_factory=list)`.
Translation applied across all 6 from_rdsap_schema_* mappers + the
flagship `from_rdsap_schema_21_0_1` used by 001479.
Pyright: mapper.py 35 → 33 (cleared 7 cohort party_wall type errors
that were pre-existing, balanced against the schema change). Cohort
cascade pins remain GREEN (66 of 66); no new test regression.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
RdSAP 10 §3.8 "Roof area" spec:
"Roof area is the greatest of the floor areas on each level...
In the case of a pitched roof with a sloping ceiling, divide the
area so obtained by cos(30°)."
The cascade previously used `top_floor_area_m2` (horizontal projection)
verbatim for the roof area calculation — correct for flat roofs and
pitched-with-loft (where assessors measure on the horizontal), but
~15% under-area for PS pitched-sloping-ceiling roofs (1/cos(30°) =
1.1547). For cert 001479 Ext1 + Ext2 (both PS sloping ceiling):
Ext1: cascade 5.37 m² × 0.15 = 0.81 W/K
worksheet 6.20 m² × 0.15 = 0.93 W/K (delta -0.12)
Ext2: cascade 1.92 m² × 2.30 = 4.42 W/K
worksheet 2.22 m² × 2.30 = 5.11 W/K (delta -0.69)
Total roof W/K shortfall: -0.81
Fix: detect PS pitched-sloping-ceiling roofs via `bp.roof_construction
_type` (string lodgement from the Summary §8 "Roof Type" line) and
apply the 1/cos(30°) inclination factor before rounding the gross
roof area.
Schema addition: `SapBuildingPart.roof_construction_type: Optional[
str] = None` mirrors the existing `floor_construction_type`. Mapper
populates it via `_strip_code(roof.roof_type)` for both Main and
Extension bps — the Elmhurst Summary lodges the roof type
explicitly (e.g. "PS Pitched, sloping ceiling" / "PA Pitched (slates
/tiles), access to loft" / "Flat").
**Result: cert 001479 Summary → mapper → cascade now lands at SAP
69.0094 EXACT (delta -0.0000) — Layer 2 GREEN at 1e-4.** Full fabric
breakdown matches the worksheet exactly:
fabric_heat_loss = 139.4957 W/K ✓
walls = 39.7652 ✓ party = 17.0700 ✓
roof = 10.3438 ✓ floor = 23.1705 ✓
windows = 43.5962 ✓ doors = 5.5500 ✓
Layer 2 status across the 7 cert chain tests:
000477 GREEN (was GREEN)
000516 GREEN (was GREEN)
001479 GREEN (new — was +1.19 before Slice 87)
000474 RED -0.7524 (Elmhurst (12) non-spec — orthogonal)
000480 RED -1.0273 (Elmhurst (12) non-spec — orthogonal)
000487 RED +0.4834 (Elmhurst (12) non-spec — orthogonal)
000490 RED -1.1042 (Elmhurst (12) non-spec — orthogonal)
Cohort cascade pins remain GREEN (66 of 66) — hand-built fixtures
have roof_construction_type=None (default) so the new code path is
inert for them; their roofs use RR detailed_surfaces with explicit
areas already.
Pyright net-zero on every touched file (heat_transmission 13 → 13,
mapper 35 → 35, epc_property_data 0 → 0).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`u_floor` defaulted to the SOLID branch for age bands C+ when both
`construction` (int code) and `description` were None, regardless of
whether the bp's own `floor_construction_type` field said "Suspended
timber". This produced U=0.60 for cert 001479 Main vs the worksheet's
U=0.65 — a -0.05 W/m²K delta × 30.45 m² → -1.52 W/K of fabric loss
shortfall.
Fix: in `heat_transmission_section_from_cert`, prefer the bp's
`floor_construction_type` string over the global `epc.floors[].
description` when computing the per-bp floor U. The bp-level field
is the per-part lodgement Elmhurst surfaces in §3 / §9 of the
Summary; the global `epc.floors` list is often empty when the
mapper sources data from a Summary PDF rather than the full
RdSAP API JSON.
Impact on cert 001479 Summary → mapper → cascade SAP delta:
BEFORE Slice 88: +0.2290 (floor U 0.60 vs target 0.65)
AFTER Slice 88: +0.0898 (floor exact match; only roof gap left)
Floor W/K breakdown for cert 001479 (mapper path):
was: 21.6480 target 23.1705 delta -1.5225
now: 23.1705 target 23.1705 delta +0.0000 ✓ EXACT
Cohort cascade pins remain GREEN (66 of 66) — the cohort hand-builts
already set `floor_construction_type` on their Main bp via the
Slice 72/75/78/82/85 Cat A bulk updates, so the new code path
applies the same suspended-timber branch that previous paths reached
via either explicit `floor_construction` int codes or the age-band
default (cohort certs are all age B which is in
`_SUSPENDED_TIMBER_DEFAULT_BANDS`, so they hit the suspended branch
either way; cert 001479 is age C and needs the explicit string).
Pyright net-zero on heat_transmission.py (13 → 13 errors).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Replace the empirical `_elmhurst_has_suspended_timber_floor` heuristic
(which keyed on Room-in-Roof < Main ground area) with the mechanical
RdSAP 10 Specification §5 rule (page 29):
- Age band A-E: U-value < 0.5 → sealed (0.1); retro insulation + no
U → sealed (0.1); otherwise unsealed (0.2)
- Age band F-M: sealed (0.1)
- Park home: unsealed (0.2)
- Only applies when Main bp's lowest floor is a "Ground floor" with
"Suspended timber" construction
The spec rule is derived in `_has_suspended_timber_floor_per_spec`
(cert_to_inputs.py) and applied in `ventilation_from_cert` whenever
the lodged `epc.sap_ventilation.has_suspended_timber_floor` is None.
Explicit lodged values (cohort hand-built fixtures) take precedence.
Impact on cert 001479 (the load-bearing API↔Elmhurst parity-test
fixture; previously the RR-based heuristic returned False for this
no-RR semi-detached, dropping (12) entirely):
Mapper → cascade → SAP delta vs worksheet 69.0094:
BEFORE: +1.1903 (mapper extracted False; cascade applied (12)=0)
AFTER : +0.2290 (mapper extracts None; spec derives True/unsealed;
cascade applies (12)=0.2 → matches worksheet)
Cohort cascade pins remain GREEN (66 of 66) — cohort hand-built
fixtures retain their explicit `has_suspended_timber_floor` values
which override the spec derivation.
Expected cohort regressions to triage in the next slice:
- 4 cohort chain tests RED (000474, 000480, 000487, 000490) — their
Elmhurst worksheets enter non-spec (12) values (0.0 or 0.2 when
spec predicts the opposite) so the mapper-path cascade now
diverges from the worksheet PDF at 1e-4.
- 6 cohort diff tests RED — mapper now produces
has_suspended_timber_floor=None while the cohort hand-builts
retain explicit True/False overrides, producing a 1-field
divergence per cohort cert.
Pyright net-zero (mapper 35→35; cert_to_inputs 35→35) — dead
`_elmhurst_has_suspended_timber_floor` removed.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final `sap_windows: LEN 5 vs 2` divergence by replacing
the cohort 000516 hand-built's 2-window collapsed encoding with 5
SapWindow entries mirroring the Summary §11 1:1. Single-bp dwelling;
single glazing-type group (PVC double / g⊥=0.76 / U=2.8); per-
orientation totals preserved:
NE (orient=2): 3.88 m² split 2.15 + 1.73 (2 rows)
SW (orient=6): 4.43 m² split 1.94 + 1.67 + 0.82 (3 rows)
Mapper interleaves NE/SW rows; hand-built mirrors that order so
list-position diffs are zero.
Cascade output unchanged: all 11 `_FIXTURE_PINS["000516"]` SapResult
pins remain GREEN at 1e-4 against worksheet `SAP value 62.7937`.
**Cohort 000516 is now fully Layer-2 GREEN.**
**All 6 cohort certs (000474, 000477, 000480, 000487, 000490, 000516)
are now Layer-2 zero-diff** — the mapper produces a load-bearing-
field-equivalent EpcPropertyData for every cohort cert. This clears
the way for closing cert 001479 (the load-bearing API↔Elmhurst
parity-test fixture; Slice 62 skeleton at 2/11 cascade pins green,
gap −3.02 SAP) and then adding the API mapper diff test (Layer 3)
and the production acceptance test (Layer 4 — ±0.5 of published SAP
69 for cert 0535-9020-6509-0821-6222).
Full sweep: 107 passed (was 105 pre-Slice-84; +2 new diff tests for
000490 + 000516), 10 failed (same 10 001479-related). Pyright net-
zero on every touched fixture across Slices 71–86.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 23 of 24 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts from Summary_000516.
pdf but the original hand-built left at their `make_minimal_sap10_
epc` / dataclass-default values. Every change is cascade-equivalent —
all 11 `_FIXTURE_PINS["000516"]` SapResult pins remain GREEN against
worksheet `SAP value 62.7937`.
000516-specific deltas:
- `wall_thickness_measured=True` on Main (Summary lodges 400 mm).
- `floor_type="Above unheated space"` (exposed timber floor, not
Ground floor) — matches the cert's `is_exposed_floor=True` for
the lowest Main floor.
- `roof_insulation_location="None"` — the Summary lodges the literal
string "None" for an uninsulated roof; mapper surfaces it
verbatim.
Standard Cat A additions (per Slice 72/75/78/82 pattern): floor
descriptive fields, 6 ventilation zero counts, draught_lobby=True,
pressure_test="Not available", top-level descriptive strings +
booleans, `number_of_storeys=3` (Main ground + first + RIR),
shower_outlets="Non-electric shower",
central_heating_pump_age_str="Unknown".
Diff count: 24 → **1**. Remaining diff is `sap_windows: LEN 5 vs 2`
— closes via Slice 86.
Pyright net-zero on the touched fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Final cohort cert mapper-vs-hand-built diff test. Cert
U985-0001-000516 (Mid-Terrace, main + 19.02 m² RIR, 5 vertical
windows + 1 roof window routed to sap_roof_windows per the mapper's
`U > 3.0` discrimination). RED with 24 load-bearing divergences —
mostly standard Cat A. Closes via Slice 85 (Cat A) + Slice 86 (1:1
window expansion 2 → 5).
After 000516 lands GREEN, **all 6 cohort certs are Layer-2 zero-
diff** — clearing the way to return to cert 001479 (Slice 62
skeleton, 2/11 cascade pins green; gap −3.02 SAP).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final `sap_windows: LEN 6 vs 3` divergence by replacing
the cohort 000490 hand-built's 3-window collapsed encoding with 6
SapWindow entries mirroring the Summary §11 1:1. Single glazing-type
group (PVC double / g⊥=0.76 / U=2.8); per-bp totals preserved:
Main NW (orient=8): 2.70 m² split 1.26 + 1.44 (2 rows)
Main NE (orient=2): 0.81 m² (1 row, unchanged)
Ext1 SE (orient=4): 5.52 m² split 1.92 + 2.16 + 1.44 (3 rows)
Cascade output unchanged: all 11 `_FIXTURE_PINS["000490"]` SapResult
pins remain GREEN at 1e-4 against worksheet `SAP value 57.3979`.
**Cohort 000490 is now fully Layer-2 GREEN** — 4 of 6 cohort certs
(000474, 000477, 000480, 000487, 000490) now zero-diff Layer-2;
000516 is the last cohort cert before returning to cert 001479.
Pyright net-zero.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 31 of 32 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts from Summary_000490.
pdf but the original hand-built left at their `make_minimal_sap10_
epc` / dataclass-default values. Every change is cascade-equivalent —
all 11 `_FIXTURE_PINS["000490"]` SapResult pins remain GREEN against
worksheet `SAP value 57.3979`.
000490-specific deltas vs prior cohort certs:
- `dwelling_type="End-Terrace house"`, `built_form="End-Terrace"` —
first end-terrace fixture (vs Mid-Terrace / Enclosed Mid-Terrace
on the other 4 cohort certs); sheltered_sides=1 is already set on
the existing SapVentilation block.
- `number_of_storeys=2` — 000490 has no room-in-roof (2-storey main
+ 2-storey extension), so dwelling height is 2 (vs 3 for the RR
cohort certs).
- `number_baths=1` on sap_heating — mapper extracts 1 from Summary
§16; cascade-equivalent (Appendix J §1a defaults to 1 if absent).
- `wall_thickness_measured=True` on **both** bps (Summary §7 lodges
measured Wall Thickness 400 mm).
Standard Cat A additions (per Slice 72/75/78 pattern): floor
descriptive fields per bp, roof_insulation_location, 6 ventilation
zero counts, draught_lobby=True, pressure_test="Not available",
top-level descriptive strings + booleans + extensions_count=1,
blocked_chimneys_count=0, shower_outlets=Non-electric shower,
central_heating_pump_age_str="Unknown".
Diff count: 32 → **1**. Remaining diff is `sap_windows: LEN 6 vs 3` —
closes via Slice 83.
Pyright net-zero on the touched fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Mirror the pattern from cohorts 000474/000477/000480/000487 for cert
U985-0001-000490 (End-Terrace, main + 1 extension, gas combi + gas-
secondary heating, sheltered_sides=1 per RdSAP §S5). RED with 32
load-bearing divergences — Cat A descriptive fields + end-terrace
dwelling_type + extensions_count + sap_windows LEN 6 vs 3. Closes
via Slice 82 (Cat A) + Slice 83 (window expansion).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final `sap_windows: LEN 5 vs 2` divergence by replacing
the cohort 000487 hand-built's 2-window collapsed encoding with 5
SapWindow entries mirroring the Summary §11 1:1. All South-facing
(orient=5) / PVC frame; two glazing-type groups; per-bp totals
preserved (cascade-equivalent):
g=0.76/U=2.8: 0.77 m² (Ext1) — unchanged
g=0.72/U=1.4: 6.69 m² total split per-bp
Main: 1.65 m² (1 row)
Ext1: 5.04 m² split 2.16 + 1.53 + 1.35 (3 rows)
Mapper places the Main window between two Ext1 rows in the §11 table;
the hand-built mirrors that order so list-position diffs are zero.
Cascade output unchanged: all 11 `_FIXTURE_PINS["000487"]` SapResult
pins remain GREEN at 1e-4 against worksheet `SAP value 61.6431`.
**Cohort 000487 is now fully Layer-2 GREEN** —
`test_from_elmhurst_site_notes_matches_hand_built_000487` passes with
zero load-bearing divergences between the mapped EpcPropertyData and
the hand-built fixture.
Full sweep: 105 passed (was 104 pre-Slice-77; +1 new diff test), 10
failed (same 10 001479-related). Pyright net-zero.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 22 of the remaining 23 mapper-vs-hand-built load-bearing
divergences on cohort cert 000487. All 11 `_FIXTURE_PINS["000487"]`
SapResult pins remain GREEN at 1e-4 against worksheet `SAP value
61.6431` (cascade-equivalent — see per-change rationale).
(1) RIR `detailed_surfaces` reorder to match the mapper's per-row
Summary §3.10 extraction order:
was: [gable_wall, gable_wall_external(u=0.86), flat_ceiling,
stud_wall(100mm/min.wool), slope(0mm)]
now: [flat_ceiling, stud_wall, slope, gable_wall,
gable_wall_external(u=0.86)]
The cascade reads these surfaces as a set (sums U × area per kind),
so list order is cascade-inert. Confirmed: all 11 cohort 000487
cascade pins GREEN post-reorder. Per-surface insulation_thickness_mm
and u_value are unchanged from the prior encoding (matches mapper).
(2) Alt-wall `_WC_TIMBER_FRAME` constant: **8 → 5**.
The prior `_WC_TIMBER_FRAME = 8` was a mislabel — SAP10 code 8 is
"Park home" per `_ELMHURST_WALL_CODE_TO_SAP10`. The mapper extracts
"TI Timber Frame" → SAP10 code **5** (Timber frame). Both codes
happen to cascade to U=1.9 at age band B (different default paths),
so the prior encoding produced the right cascade output despite the
wrong semantic; switching to 5 mirrors the cert truth and the mapper.
Dropped the alt-wall's `wall_insulation_thickness='150'` workaround
and `u_value=1.90` explicit pin — the cascade for `wall_construction
=5` at age B resolves to U=1.9 from the age-band default; mapper
passes None for both fields and the cascade computes them.
Remaining diff: 1 (`sap_windows: LEN 5 vs 2`) — Slice 80.
Pyright net-zero on the touched fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 23 of 45 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts from Summary_000487.
pdf but the original hand-built left at their `make_minimal_sap10_
epc` / dataclass-default values. Every change is cascade-equivalent —
none alter `_FIXTURE_PINS["000487"]` SapResult fields (all 11 1e-4
pins remain GREEN against worksheet `SAP value 61.6431`).
Mirrors the Slice 64 / 72 / 75 pattern. 000487-specific deltas:
- `wall_thickness_measured=True` on **both** bps (Summary §7 lodges
measured thickness for Main and Ext1 on this cert).
- Floor descriptive: Main "Ground floor" + suspended timber; Ext1
"Above unheated space" + suspended timber (the cert's
`is_exposed_floor=True` for the lowest Ext1 floor).
- `dwelling_type="Enclosed Mid-Terrace house"`,
`built_form="Enclosed Mid-Terrace"` — the Summary distinguishes
Enclosed from plain Mid-Terrace; mapper preserves the distinction.
- `shower_outlets=ShowerOutlets(shower_outlet_type="Electric
shower")` — 000487 lodges 1 instantaneous electric shower (vs
Non-electric on 000477/000480 cohort certs).
- `extensions_count=1`, plus standard top-level booleans,
`number_of_storeys=3`, ventilation zero counts.
Diff count: 45 → **22**. Remaining diffs are structural / encoding-
choice:
- RIR `detailed_surfaces` ordering mismatch + per-surface encoding
(handbuilt pins explicit `u_value=0.86` on gable_wall_external;
mapper extracts insulation_thickness=100 + mineral_wool) — Slice 79
- Alt-wall `wall_construction=8 (SAP10 Park-home)` is mislabeled in
the hand-built — Elmhurst's "TI Timber Frame" maps to SAP10 code 5
(per `_ELMHURST_WALL_CODE_TO_SAP10`); mapper produces the correct
code 5 — Slice 79
- `sap_windows: LEN 5 vs 2` — Slice 80
11 cohort 000487 cascade pins still GREEN; pyright net-zero.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Mirror the cohort 000474/000477/000480 mapper-vs-hand-built diff
tests for cert U985-0001-000487 (Enclosed Mid-Terrace, main + 1
extension + RIR with explicit-U gable_wall_external, gas combi, 1
electric shower, 1.43 m² timber-frame alt wall on the extension).
RED with ~45 load-bearing divergences — larger than 000477/000480
because of the RIR detailed_surfaces ordering difference, the alt-
wall encoding wrinkle (hand-built `_WC_TIMBER_FRAME=8` is actually
SAP10 Park-home; mapper extracts the correct timber-frame code 5),
and `dwelling_type='Enclosed Mid-Terrace house'` (not plain Mid-
Terrace). Closes via Slice 78 (Cat A) + Slice 79 (alt-wall + RIR
reorder) + Slice 80 (window expansion).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final `sap_windows: LEN 7 vs 2` divergence by replacing
the cohort 000480 hand-built's 2-window collapsed encoding with 7
SapWindow entries mirroring the Summary §11 1:1. Single glazing-type
group (PVC double / g⊥=0.76 / U=2.8); per-bp totals preserved:
Main NE (orient=2): 8.74 m² split into 2.16 + 1.92 + 0.6 + 1.32
+ 2.04 + 0.7 (6 rows)
Ext1 SW (orient=6): 1.80 m² unchanged
Mapper interleaves the Ext1 SW row between Main NE rows 4 and 5; the
hand-built mirrors that order so list-position diffs are zero.
`window_location` carries "Main" or "1st Extension" — same string-
encoded per-bp lookup pattern as Slice 69 (cohort 000474).
Cascade output unchanged: all 11 `_FIXTURE_PINS["000480"]` SapResult
pins remain GREEN at 1e-4 against worksheet `SAP value 61.2986`.
**Cohort 000480 is now fully Layer-2 GREEN** —
`test_from_elmhurst_site_notes_matches_hand_built_000480` passes with
zero load-bearing divergences between the mapped EpcPropertyData and
the hand-built fixture.
Full sweep: 104 passed (was 103 pre-Slice-74; +1 new diff test),
10 failed (same 10 001479-related as before). Pyright net-zero.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 31 of 32 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts from Summary_000480.
pdf but the original cohort hand-built left at their `make_minimal_
sap10_epc` / dataclass-default values. Every change is cascade-
equivalent — none alter `_FIXTURE_PINS["000480"]` SapResult fields
(all 11 1e-4 pins remain GREEN against worksheet `SAP value 61.2986`).
Mirrors the Slice 64 / 72 pattern. 000480-specific deltas vs 000477:
- Two SapBuildingParts (Main + Ext1) → Cat A descriptive fields
applied per-bp; Ext1 floor is "Above unheated space" (not "Ground
floor") because the extension hangs over an open passageway (the
cert's `is_exposed_floor=True` for the lowest Ext1 floor).
- `roof_insulation_thickness=300` on Main — cascade-inert because the
RR (19.83 m²) is larger than the Main storey footprint (15.28 m²),
so Main has no external roof line; set for field parity with the
mapper, which extracts the §8 Main row's 300 mm regardless.
- `extensions_count=1` — was 0 by default; the mapper extracts it
from `len(survey.extensions)` (Slice 54 fix).
Standard Cat A additions (per Slice 72 pattern): floor descriptive
fields, roof_insulation_location, 6 ventilation zero counts,
draught_lobby=True, pressure_test="Not available", top-level
descriptive strings + booleans + number_of_storeys=3, shower_outlets,
central_heating_pump_age_str.
Diff count: 32 → **1**. Remaining diff is structural:
- `sap_windows: LEN 7 vs 2` — closed via the next-slice 1:1 expansion.
11 cohort 000480 cascade pins still GREEN; pyright net-zero on the
touched fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Mirror the cohort 000474/000477 mapper-vs-hand-built diff tests for
cert U985-0001-000480 (mid-terrace, main + 1 extension + 19.83 m²
RIR, gas combi). RED with 32 load-bearing divergences — wider than
000477 because of the second SapBuildingPart, the missing
`extensions_count` mapping, an extra `roof_insulation_thickness`
Cat-A gap on Main, and a wider 7-vs-2 sap_windows expansion.
Closes via the same Slice 72 + 73 pattern.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final `sap_windows: LEN 7 vs 3` divergence by replacing
the cohort 000477 hand-built's glazing-type-collapsed 3-window
encoding with 7 SapWindow entries mirroring the Summary §11 1:1 —
the same row breakdown the Elmhurst mapper extracts. Total area per
glazing-type group is preserved (cascade-equivalent):
g=0.72/U=2.0: 8.04 m² total — was 2 rows (E 1.28 + W 6.76),
now 6 rows (E 1.28 + W [1.8 + 1.7 + 1.36 + 1.36 + 0.54])
g=0.76/U=2.8: 1.17 m² in 1 row (unchanged)
Cohort 000477 is a single-bp dwelling, so every window's
`window_location` is "Main" — no per-bp apportionment complexity.
Cascade output unchanged: all 11 `_FIXTURE_PINS["000477"]` SapResult
pins remain GREEN at 1e-4 against worksheet `SAP value 65.0057`.
**Cohort 000477 is now fully Layer-2 GREEN** —
`test_from_elmhurst_site_notes_matches_hand_built_000477` passes with
zero load-bearing divergences between the mapped EpcPropertyData
(from `Summary_000477.pdf`) and the hand-built fixture.
Full sweep: 103 passed (was 102 pre-Slice-71; +1 new diff test),
10 failed (same 10 001479-related as documented in the handover).
Pyright net-zero on the touched fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 23 of 24 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts from Summary_000477.
pdf but the original cohort hand-built left at their `make_minimal_
sap10_epc` / dataclass-default values. Every change is cascade-
equivalent — none alter `_FIXTURE_PINS["000477"]` SapResult fields
(all 11 1e-4 pins remain GREEN against worksheet `SAP value 65.0057`).
Mirrors the Slice 64 pattern on the cohort 000474 hand-built:
SapBuildingPart additions (Main only — 000477 is a single-bp mid-
terrace, no extension):
- `wall_thickness_measured`: False → True. Summary §7 lodges Wall
Thickness 380 mm explicitly; the cascade doesn't consume this flag.
- `floor_type`, `floor_construction_type`, `floor_insulation_type_
str`, `floor_u_value_known`: surfaced from Summary §9 ("G Ground
floor" / "T Suspended timber" / "A As built" / U-value Known = No).
Cascade reads the int codes on SapFloorDimension, not these strings.
- `roof_insulation_location="Joists"`: surfaced from Summary §8.
SapVentilation additions (all cascade-equivalent — `None` defaults to
0 throughout the §2 cascade chain):
- 6 explicit zero counts (`open_flues`, `closed_flues`, `boiler_
flues`, `other_flues`, `passive_vents`, `flueless_gas_fires`)
- `pressure_test="Not available"` (descriptive — cert lodges no test)
- `draught_lobby=True` (legacy field; cascade reads `has_draught_
lobby=False` which stays as set)
Top-level additions via `make_minimal_sap10_epc`:
- `blocked_chimneys_count=0`, `dwelling_type="Mid-Terrace house"`,
`built_form="Mid-Terrace"`, `property_type="House"`
Post-construction mutations (helper doesn't expose these as kwargs):
- `has_conservatory=False`, `any_unheated_rooms=False`,
`number_of_storeys=3` (cohort 000477 has ground + first + RIR)
- `sap_heating.shower_outlets=ShowerOutlets(Non-electric shower)`
- `sap_heating.main_heating_details[0].central_heating_pump_age_str=
"Unknown"`
Diff count: 24 → **1**. The remaining diff is structural:
- `sap_windows: LEN 7 vs 3` — mapper extracts 1:1 from §11 table;
the hand-built collapses by glazing-type group, preserving total
area. Cascade-equivalent but not field-equal. Closes via the same
1:1 expansion that Slice 69 applied to cohort 000474 (5 → 7).
11 cohort 000477 cascade pins still GREEN; pyright net-zero on the
touched fixture file.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Mirror the cohort 000474 mapper-vs-hand-built diff test for cert
U985-0001-000477 (single-bp mid-terrace, age band B, RIR with stud
walls + party gables, no extension). RED with 24 load-bearing
divergences — the toolchain (allow-list, exclusion list, diff helper)
from Slice 63 transfers cleanly; closing 000477's diffs will follow
the same patterns as Slices 64-70 (Cat A bulk-fix, mapper surfacing,
hand-built updates).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
User reframed the end goal explicitly: the production flow is
`API JSON → EpcPropertyDataMapper.from_api_response → SAP calculator`
landing within ±0.5 of the API-published SAP. The Elmhurst-site-notes
work is the cross-validation route — same dwelling, independent path
into EpcPropertyData. Once both routes agree on cert 001479, the API
mapper is validated by transitivity.
Restructure the handover around four nested validation layers:
Layer 1 (hand-built cascade pin): 6 cohort certs GREEN; 001479 partial
Layer 2 (Elmhurst ≡ hand-built): cohort 000474 GREEN; 5 others pending
Layer 3 (API ≡ Elmhurst): test doesn't exist yet
Layer 4 (API cascade ±0.5): 72.08 vs 69 (delta +3.08)
Each layer validates the one below. Closing inner-most first means
upper layers can lean on it as reference.
Documents tools/patterns built in slices 63-70:
- `_LOAD_BEARING_FIELDS` allow-list (~40 cascade/semantic fields)
- `_NON_LOAD_BEARING_WINDOW_SUBFIELDS` deny-list (descriptive int/str
encoding noise)
- `_diff_load_bearing` recursive helper (strict-pyright-clean)
- `test_from_elmhurst_site_notes_matches_hand_built_NNNNNN` tracer-
bullet pattern (000474 is the worked example)
Next-step ordering: parametrize over 5 other cohort certs, complete
001479 hand-built (currently 2/11 cascade pins green; gap −3.02 SAP),
add cert 001479 to diff test, then add API mapper → hand-built diff
test, then the production-flow acceptance pin in test_golden_fixtures
for cert 001479.
Lists source-data caveats (the M-vs-L Ext1 age discrepancy on 001479).
Conventions to honour (AAA, abs(diff)<=tol, one slice=one commit,
1e-4 Elmhurst / 0.5 API, no widening, pyright net-zero). Cached
artefacts (golden JSON, Summary PDF, worksheet PDF) noted.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the final 49 → 0 diffs in two moves:
1. **Filter non-load-bearing SapWindow sub-fields from the diff.** The
Elmhurst mapper surfaces Summary §11 strings (window_type='Window',
glazing_type='Double between 2002 and 2021', glazing_gap='12 mm',
data_source='Manufacturer', permanent_shutters_present='None')
while the cohort `make_window` helper produces API-style int codes
for the same fields. None of these affect the SAP cascade — it
reads only window_width / window_height / orientation /
window_location / frame_factor / window_transmission_details.
{u_value, solar_transmittance}. Adding `_NON_LOAD_BEARING_WINDOW_
SUBFIELDS` + `_is_excluded_path` to the diff helper drops them
from the comparison without changing the load-bearing scope. Per
the user's earlier "load-bearing only" decision — encoding noise
that doesn't change the cascade output is excluded.
2. **`make_window` helper now defaults `frame_factor=0.7`.** The
SAP10.2 Table 6c PVC default (and the modal value the Elmhurst
mapper surfaces from Summary §11). Previously the helper left it
`None`, which the cascade resolves to 0.7 internally; setting it
explicitly is cascade-equivalent and closes the last 7 diffs.
Diff count for cohort 000474:
Slice 63 baseline: 50
Slice 64 (Cat A): 14
Slice 65 (HW): 12
Slice 66+67 (mapper): 5
Slice 68 (party-wall): 1
Slice 69 (windows): 49 (encoding-noise surface)
Slice 70 (filter): **0** — diff test now GREEN
`test_from_elmhurst_site_notes_matches_hand_built_000474` PASSES.
First cohort cert fully validated at the EpcPropertyData load-
bearing-field level. All 66 cohort cascade pins remain GREEN at
1e-4. Pyright net-zero (0 errors on touched files).
Next slices: parametrize the diff test over the 5 other cohort
certs (000477, 000480, 000487, 000490, 000516) — each may have
its own bulk-update + mapper-tweak pattern, but the toolchain
(diff helper, exclusion list, _LOAD_BEARING_FIELDS, helper
defaults) is in place. Then 001479 (after Slice 62 hand-built
hits 1e-4). Then the API mapper diff test (currently the API
mapper has its own gaps — Slice 58/59/60 cascade fixes closed
golden cert residuals but field-level cross-mapper parity isn't
asserted yet).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the `sap_windows: LEN 7 vs 5` divergence by replacing the
cohort hand-built's glazing-type-collapsed 5-window encoding with 7
SapWindow entries mirroring the Summary §11 1:1 — the same row
breakdown the Elmhurst mapper extracts. Per-window curtain-transform
U_eff aggregates to the same total as before:
Group g=0.72/U=2.0: 6.22 m² across 4 rows (was 3 rows × wider W)
Group g=0.76/U=2.8: 5.50 m² across 3 rows (was 2 rows × wider W)
Cascade output is unchanged — all 11 cohort 000474 SapResult pins
remain GREEN at 1e-4. The per-bp window apportionment from Slice 59
(`_window_bp_index` in heat_transmission_from_cert) handles both the
prior int-zero `window_location` and the new "Main"/"Nth Extension"
str locations the mapper surfaces; cohort 000474 has uniform per-bp
wall U so the apportionment is heat-loss-invariant either way.
Surfaces a previously-hidden gap: now that the LEN matches, the
diff test reveals **49 per-window sub-field divergences** between
the cohort `make_window` helper (API-style int codes for
`glazing_type`, `window_type`, `window_wall_type`, `glazing_gap`,
`data_source`, bool `permanent_shutters_present`, None
`frame_factor`) and the Elmhurst mapper (Summary-style strings for
the same fields + `frame_factor=0.7`).
That's the next chunk to address — most likely path: normalise the
Elmhurst mapper to produce API-style int codes for the window
descriptive fields, so both mappers produce the same dataclass
shape. The cascade reads `window_transmission_details.u_value` /
`solar_transmittance` + `window_width` × `window_height` +
`orientation` + `window_location` — none of the descriptive
divergences listed above affect SAP output.
Diff count: 1 → 49 (surface, not regression). Cohort cascade pins
green; pyright 0 errors on the fixture.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 4 of 5 remaining cohort 000474 diffs (5 → 1):
**Mapper:** Add "U" → 0 to `_ELMHURST_PARTY_WALL_CODE_TO_SAP10`. The
modal cohort lodgement Summary §7 "Party Wall Type: U Unable to
determine" was previously falling through to None; the cohort hand-
built convention uses 0 as the explicit "unknown" sentinel. The
cascade resolves both 0 and None to the same `u_party_wall` default
(0.25), so cascade output is unchanged. Closes 3 diffs (one per bp).
**Hand-built:** Set `central_heating_pump_age_str="Unknown"` on cohort
000474 Main heating detail (post-construction since the helper
doesn't expose the kwarg). Matches the Elmhurst mapper's surfaced
value from Summary §14 "Heat pump age: Unknown" — the str dual-
encoding internal_gains.py reads. Closes 1 diff.
All 66 cohort cascade pins remain GREEN at 1e-4. Pyright 35-error
baseline preserved on mapper.py; 0 errors on the hand-built file.
Remaining 1 diff on cohort 000474:
- `sap_windows: LEN 7 vs 5` — the cohort hand-built collapsed §11
by glazing-type × orientation × bp group (preserving total area,
cascade-equivalent but not field-equal); the mapper extracts 1:1
with the worksheet's 7 §11 table rows. Next slice will expand the
hand-built to 7 individual SapWindow entries matching the mapper.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 9 mapper-side load-bearing field gaps surfaced by the cohort
000474 mapper-vs-hand-built diff (was 12, now 5 remaining):
**Slice 66 — country code + draught-lobby fix:**
- Set `country_code="ENG"` in `from_elmhurst_site_notes`. The Elmhurst
U985 / P960 surveyor toolchain operates on English certs only; the
Summary doesn't lodge country explicitly but the cascade's `u_floor`
/ `u_basement_floor` / `u_door` read it for table selection. Cohort
hand-builts already encode 'ENG' so the cascade was tolerating the
None default; matching the canonical value closes the diff.
- `_map_elmhurst_ventilation` now sets `has_draught_lobby=True` only
when Summary lodges "Yes"/"Present". The cohort's modal lodgement
"Unable to determine" maps to `False` — matching the cohort hand-
built convention (conservative no-lobby cascade path). The legacy
`draught_lobby` field is unchanged; the cascade reads
`has_draught_lobby` in preference.
**Slice 67 — heating field surfacing:**
- `boiler_flue_type`: Add `_ELMHURST_FLUE_TYPE_TO_SAP10` map (Open=1,
Balanced=2, Fan-assisted balanced=3, Room-sealed=4). Cohort 000474's
"Balanced" Summary §14 lodgement → 2, matching hand-built.
- `emitter_temperature`: `_elmhurst_emitter_temperature_int` parses
the Summary §14 "Design flow temperature" string to int (≥45 °C →
1, lower → 0; "Unknown" defaults to 1 per Table 4d worst-case).
- `central_heating_pump_age`: dual-encode int alongside the existing
`_str` field via `_elmhurst_pump_age_int` (Unknown → 0, Pre 2013 →
1, otherwise → 2). The cascade reads `_str`; the int is for cross-
mapper field parity only.
- `main_heating_number=1`: default single main heating.
- `water_heating_fuel`: parse Summary §15 "Water Heating Fuel Type"
via the existing `_elmhurst_main_fuel_int` map. Cohort 000474's
"Mains gas" → 26.
All 11 newly-surfaced fields are metadata-only on the SAP cascade
(grep confirms none feature in `packages/domain/src/domain/sap/`
outside test fixtures). All 66 cohort cascade pins remain GREEN at
1e-4. Pyright 35-error baseline preserved on mapper.py.
Diff count for cohort 000474:
Slice 63 baseline: 50
Slice 64 (Cat A bulk): 14
Slice 65 (HW handbuilt): 12
Slice 66 (country+lobby): 10
Slice 67 (heating ints): **5**
Remaining 5 diffs:
- 3× `sap_building_parts[*].party_wall_construction`: None vs 0
(cohort sentinel convention — needs mapper-side fix to surface 0
when no party wall is lodged, OR hand-built update to drop sentinel)
- `sap_heating.main_heating_details[0].central_heating_pump_age_str`:
mapped='Unknown' vs handbuilt=None (hand-built should populate the
str dual)
- `sap_windows: LEN 7 vs 5` (Cat C structural — cohort hand-built
collapsed by glazing-type group, mapper extracts 1:1 with §11 table)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 2 of 14 remaining diffs by populating Appendix J inputs the
Elmhurst mapper surfaces from Summary §16:
- `sap_heating.number_baths=1` (passed via make_sap_heating kwarg)
- `sap_heating.shower_outlets = ShowerOutlets(Non-electric)` (set
post-construction because the helper doesn't expose the field;
added the dataclass imports for SCM completeness)
Cascade-equivalent: number_baths=1 and one non-electric mixer outlet
without WWHRS are the implicit Appendix J defaults when nothing is
lodged. All 11 cohort 000474 cascade pins remain GREEN at 1e-4.
Diff count: 14 → 12. Pyright net-zero (0 errors).
Remaining 12 diffs split:
- 7 mapper-needs-to-surface (country_code, water_heating_fuel,
boiler_flue_type, emitter_temperature, main_heating_number,
has_draught_lobby, central_heating_pump_age int↔str)
- 3 party_wall_construction sentinel (None vs 0) across bps
- 1 sap_windows: LEN 7 vs 5 (collapse vs 1:1 structural decision)
- 1 dwelling_type / built_form casing nuance (resolved in Slice 64
bulk-update; remaining 1 was for one bp's encoding)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes 36 of the 50 mapper-vs-hand-built load-bearing divergences by
populating fields the Elmhurst mapper extracts but the original
cohort hand-built left at their `make_minimal_sap10_epc` / dataclass-
default values. Every change is cascade-equivalent — none alter
`_FIXTURE_PINS["000474"]` SapResult fields (all 11 1e-4 pins remain
GREEN against worksheet `SAP value 62.2584`).
Per-SapBuildingPart additions (Main, Ext1, Ext2):
- `wall_thickness_measured`: False → True. Summary §7 lodges Wall
Thickness 280 mm explicitly; the cascade doesn't read this field
(grep `wall_thickness_measured` across domain/sap/ returns no
consumer outside test fixtures), so flipping it is field-level-
only.
- `floor_type`, `floor_construction_type`, `floor_insulation_type_str`,
`floor_u_value_known`: surfaced from Summary §9 ("G Ground floor" /
"U Above unheated space" / "T Suspended timber" / "A As built" /
U-value Known = No). Strings carry the lodged text for cross-mapper
parity; cascade reads the int codes on SapFloorDimension.
- `roof_insulation_location`, `roof_insulation_thickness`: surfaced
from Summary §8 ("J Joists" + "100 mm"). Cascade's `u_roof` for
age B at thickness=100 returns the same 0.40 W/m²K as the age-B
default (thickness=None falls through to `_ROOF_BY_AGE['B']=0.40`),
so the cascade output is identical.
SapVentilation additions (all cascade-equivalent — `None` defaults to
0 throughout the §2 cascade chain):
- 6 explicit zero counts (`open_flues`, `closed_flues`, `boiler_flues`,
`other_flues`, `passive_vents`, `flueless_gas_fires`)
- `pressure_test="Not available"` (descriptive, no test was lodged)
- `draught_lobby=True` (the legacy field; cascade reads
`has_draught_lobby=False` which is set already, so True on the
legacy field has no cascade effect)
Top-level additions via `make_minimal_sap10_epc`:
- `extensions_count=2` (Slice 54 fix on mapper made this surface; the
hand-built was carrying the pre-Slice-54 hard-coded 0)
- `blocked_chimneys_count=0`, `dwelling_type="Mid-Terrace house"`,
`built_form="Mid-Terrace"`, `property_type="House"`
Post-construction mutations (helper doesn't expose these as kwargs):
- `has_conservatory=False`, `any_unheated_rooms=False`,
`number_of_storeys=2`, `hydro=False`, `photovoltaic_array=False`
Diff count: 50 → **14**. The remaining 14 are real semantic gaps for
the next slices to close:
Cat B (mapper needs to surface 7 fields):
- country_code (Elmhurst mapper produces None; should set 'ENG')
- sap_heating.water_heating_fuel (None vs 26 — gas main heating
should imply gas water heating fuel)
- main_heating_details[0].boiler_flue_type (None vs 2 — Summary
§14.1 lodges "Balanced" flue type)
- main_heating_details[0].emitter_temperature ('Unknown' vs 1)
- main_heating_details[0].main_heating_number (None vs 1)
- sap_ventilation.has_draught_lobby (None vs False)
- dual-encoded central_heating_pump_age int/str
Cat C (structural shape, 2 diffs):
- sap_windows: LEN 7 vs 5 (mapper 1:1 with §11 table vs hand-built
collapsed by glazing-type group, preserving total area —
cascade-equivalent but not field-equal)
- sap_building_parts[*].party_wall_construction: None vs 0
(cohort convention sentinel; the cohort 000474 docstring
established `0 = "Unable to determine"`)
Cat B handbuilt-needs (hand-built should add 2 fields the mapper
already surfaces):
- sap_heating.shower_outlets (mapper extracts 'Non-electric shower')
- sap_heating.number_baths (mapper extracts 1)
11 cohort cascade pins still GREEN; pyright net-zero (0 errors on
the touched fixture file). Tracer-bullet diff test stays RED with
14 divergences (was 50).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
User-driven pivot to the cohort-first validation strategy: the 6
existing hand-built `_elmhurst_worksheet_NNNNNN.build_epc()` fixtures
already cascade to their worksheet PDFs at 1e-4 — they ARE the
100%-correct calculator-input ground truth. Adding diff tests that
assert `from_elmhurst_site_notes(pdf) == hand_built()` surfaces every
silent divergence the existing chain tests miss (because chain tests
only check cascade output, not field-level EpcPropertyData equality).
Adds `test_from_elmhurst_site_notes_matches_hand_built_000474` as the
tracer-bullet first cohort case. The test:
1. Maps Summary_000474.pdf through the Elmhurst extractor + mapper.
2. Builds the hand-built EpcPropertyData via
`_elmhurst_worksheet_000474.build_epc()`.
3. Recursively diffs the two across a `_LOAD_BEARING_FIELDS`
allow-list (40 top-level fields driving the SAP cascade or
cross-mapper semantic equivalence; explicitly excludes cert
metadata, EnergyElement descriptive lists, registration dates,
and other fields that vary by mapper pathway without semantic
disagreement — these are noise per user decision).
RED status committed as the load-bearing TDD forcing function:
50 load-bearing divergences across 4 categories:
Cat A — encoding-only / cascade-equivalent (~30 diffs):
* Ventilation flue counts `0 vs None` (cascade defaults None to 0)
* Dual-encoded sub-fields (`floor_construction_type` str-side,
`roof_insulation_location` str-side, etc.)
* Mapper-surfaces-descriptive-only fields (`floor_type`,
`floor_u_value_known`)
Cat B — real cascade-affecting gaps (~10 diffs):
* `sap_heating.water_heating_fuel`: None vs 26 (mains gas)
* `sap_heating.shower_outlets`: extracted vs None
* `sap_heating.number_baths`: 1 vs None
* `country_code`: None vs 'ENG'
* `built_form`: 'Mid-Terrace' vs None
* `boiler_flue_type`, `central_heating_pump_age` dual-encoding
* `dwelling_type` casing 'Mid-Terrace house' vs 'Mid-terrace house'
* `wall_thickness_measured`: True vs False
Cat C — structural shape divergences (1 diff):
* `sap_windows: LEN 7 vs 5` — mapper extracts 1:1 with §11 table;
cohort hand-built collapsed entries by glazing-type group
(preserving total area, cascade-equivalent but not field-equal).
Cat D — Slice-54-style hand-built staleness (~5 diffs):
* `extensions_count: 2 vs 0` — Slice 54 fix landed on mapper;
hand-built still uses old hardcoded 0
* `party_wall_construction: None vs 0` — cohort convention sentinel
* Hand-built ages prior to current mapper conventions
Two RED forcing functions on the branch now:
- test_summary_001479_full_chain_sap_matches_worksheet_pdf_exactly
(delta 1.19 SAP vs 69.0094)
- test_from_elmhurst_site_notes_matches_hand_built_000474
(50 load-bearing field divergences)
Strict-pyright net-zero on the chain test file (0 errors); cohort
chain tests all still pass (13 green / 2 RED).
Next slices will chip away at the diff list — bulk-update cohort
hand-builts for Cat A/D (mechanical) then attack Cat B/C with
per-field design decisions. Once 000474 closes, parametrize over
the 5 other cohort certs, then API-mapper diff test, then cross-
mapper parity falls out.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Update NEXT_AGENT_PROMPT.md with the pivot to the rigorous cohort
pattern: cert 001479's hand-built `_elmhurst_worksheet_001479.py`
becomes the ground-truth EpcPropertyData. Cross-mapper parity work
then collapses to "both mappers produce hand-built-equivalent
EpcPropertyData".
Two parallel workstreams documented:
1. Iterate the hand-built skeleton (Slice 62) until all 11 cascade
pins hit 1e-4. Current state: 2/11 green (pumps_fans, lighting);
sap_score_continuous gap −3.02 SAP. Likely next slices: HW demand
routing, §2 ventilation tuning, thermal mass parameter, multiple-
glazed proportion.
2. Once hand-built is GREEN, add `test_elmhurst_mapper_matches_hand_
built` + `test_api_mapper_matches_hand_built` over the 7-cert
cohort (000474..000516 + 001479). Every field diff = mapper bug
to close. Cross-parity collapses to "both mappers produce
hand-built-equivalent".
Documents the M-vs-L Ext1 age-band source-data conflict (hand-built
uses worksheet's L; Elmhurst mapper trusts Summary's M) — surfaces
as a known caveat in cross-mapper diff.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
User-driven pivot from cascade chain-pin chase to the rigorous cohort
pattern: a hand-built EpcPropertyData that cascades to the worksheet
at 1e-4 is the ground truth for cross-mapper parity testing. Both the
Elmhurst mapper and the API mapper should ultimately produce a hand-
built-equivalent EpcPropertyData for cert 001479; every divergence
from the hand-built is a mapper bug.
This skeleton encodes the cert 001479 worksheet inputs:
- 3 building parts (Main C, Ext1 L, Ext2 C) with per-bp wall U
- Main party wall CU (cavity unfilled, U=0.50, lodged via WC_CAVITY=4)
- Cantilevered upper-storey Ext2 with `is_exposed_floor=True` (U=1.20)
- Ext2 PS sloping-ceiling roof at `roof_insulation_thickness=0`
(Slice 57 PS+pre-1950 path → Table 16 row 0 U=2.30)
- Main 300 mm joist roof insulation → U=0.14
- 8 Main windows (U=2.8, g=0.76) + 1 Ext1 window (U=1.4, g=0.72)
- Worcester Greenstar 30i (PCDF 17507) main + SAP 605 gas fire secondary
(Slice 58 mains-gas secondary fuel cost routing)
- Sheltered sides 1, 2 intermittent fans, 90% draught-proof, 23 LEDs
Adds an `001479` entry to `_FIXTURE_PINS` + `_FIXTURE_MODULES` in
`test_e2e_elmhurst_sap_score.py` with the worksheet PDF's 11
cascade-output line refs:
sap_score 69 (258)
sap_score_continuous 69.0094 "SAP value"
ecf 2.2215 (257)
total_fuel_cost_gbp 600.4001 (255)
co2_kg_per_yr 2687.3610 (272)
space_heating_kwh_per_yr 8103.7054 Σ (98c)
main_heating_fuel_kwh_per_yr 8194.7583 (211)
secondary_heating_fuel_kwh_per_yr 2025.9264 (215)
hot_water_kwh_per_yr 2358.3123 (219)
pumps_fans_kwh_per_yr 160.0000 (231)
lighting_kwh_per_yr 163.3584 (232)
Current state of the hand-built cascade vs worksheet:
Pin Cascade Expected PASS?
sap_score_continuous 65.99 69.01 no, -3.02
total_fuel_cost_gbp 658.92 600.40 no, +58.52
main_heating_fuel_kwh_per_yr 9359.6 8194.8 no
pumps_fans_kwh_per_yr 160.0 160.0 PASS
lighting_kwh_per_yr 163.4 163.4 PASS (after
LED/CFL split)
(... 9 others all failing by various deltas)
2/11 pins green. The remaining ~3 SAP gap means the hand-built has
input gaps that produce more loss/cost than Elmhurst's calc. Likely
suspects (slice candidates):
- HW demand: cascade likely over-counts (combi vs cylinder routing,
Tcold model)
- Internal gains: appliance + cooking energy share
- §2 ventilation tuning (chimney/flue counts, suspended-floor flag)
- Thermal mass parameter (250 default — confirm worksheet matches)
- Multiple-glazed proportion (cascade reads None → may default
unfavourably for solar gains)
Documents source-data caveat in the fixture docstring: Summary §3
says Ext1 age "M 2023 onwards"; worksheet header says "Ext1: L".
Hand-built uses 'L' to mirror the worksheet (which is the calc's
input source of truth); Elmhurst mapper produces 'M' from the
Summary — cross-mapper diff will flag this as a known caveat.
All 6 cohort cascade pins remain green at 1e-4 (66/66 fixture pins).
Pyright net-zero on the new fixture file.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Update NEXT_AGENT_PROMPT.md for the TDD session that landed 3 more
slices on top of Session 1's fabric work:
58: secondary fuel cost routes through lodged secondary_fuel_type
(closes the biggest single gap on cert 001479 — 9 SAP)
59: heat_transmission apportions windows per bp via window_location
60: thermal bridging y uses primary bp's age (dwelling-wide)
Chain pin `test_summary_001479_full_chain_sap_matches_worksheet_pdf_
exactly` is committed RED as the load-bearing TDD forcing function:
Pre-workstream: delta +5.84 SAP (cascade 63.17 vs target 69.0094)
Post-Slice 60: delta −1.19 SAP (cascade 70.20 vs target 69.0094)
Per-bp fabric U-values all match the worksheet exactly. Remaining
1.19 SAP overshoot maps to ~3 W/K of HLC undercount in roof + floor:
- Ext2 PS sloping-ceiling roof area uses floor projection (1.92 m²)
instead of slant area (2.22 m²). −0.81 W/K.
- Main ground-floor U: `u_floor` Table 19 returns 0.60 for age C;
worksheet expects 0.65 (same as age B). −1.52 W/K.
- (31) external area under-count drives bridging gap. −2.08 W/K.
Slice 61 (SapFloorDimension.floor_lodged_u_value override using
Summary §9 "Default U-value") was attempted and reverted: closed
001479 floor gap exactly but broke 000474 cohort's 1e-4 pin (its
cascade calibration uses u_floor age-B 0.77 vs Summary's lodged
0.75). Next session needs a different fix — Table 19 audit for
age C, or selective override.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`heat_transmission_from_cert` computed `y = thermal_bridging_y(age_
band=part.construction_age_band)` per bp, then applied each bp's y
to its own external area. That mis-models multi-age dwellings:
RdSAP10 Table 21 indexes y by the *dwelling's* age band, and Elmhurst's
worksheet reports y as a single user-defined value applied to total
exposed area (cert 001479 worksheet: "Thermal Bridges Bridging User
Input Y 0.15").
For cohort certs with uniform age-band bps the change is heat-loss-
invariant. For cert 001479 (Main=C → 0.15, Ext1=M → 0.08, Ext2=C →
0.15) the cascade was under-counting Ext1's bridging by 0.07 × 27.28
m² ≈ 1.9 W/K. For golden cert 7536-3827 (Main=D, Ext1=L, Ext2=F) the
same per-bp split was costing ~2 W/K of bridging.
Use the primary part's (parts[0]) age band for a single dwelling-wide
`dwelling_y`, applied across all parts in the heat-loss loop.
Cert 001479 chain pin closes another step: cascade SAP 70.38 → 70.20
(target 69.0094, delta 1.37 → 1.19). Golden 7536-3827 residuals
tighten in lockstep: SAP +4 → +3, PE -24.73 → -22.53, CO2 -0.66 → -0.60.
Other 7 golden certs unchanged (single-bp or uniform-age multi-bp).
70 of 71 chain+golden+heat-transmission tests green; chain pin still
RED (load-bearing). Pyright net-zero (13-error baseline on
heat_transmission.py preserved).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`heat_transmission_from_cert` hardcoded all window + door area to the
first sap_building_part (Main) via the `if i == 0` branch. That's
heat-loss-invariant for cohort certs whose per-bp wall U is uniform
(cohort 6 all share wall_construction + wall_insulation_type across
bps) but wrong for cert 001479 where Ext1's wall U=0.26 (filled
cavity, age M) differs sharply from Main's U=0.70 (uninsulated
cavity, age C). Worksheet §3:
External walls Main 47.13 net × 0.70 = 32.99 (29a)
External walls Ext1 10.17 net × 0.26 = 2.64 (29a)
External walls Ext2 5.90 × 0.70 = 4.13 (29a)
Σ walls 39.77
Pre-slice the cascade attributed all 9 windows to Main, leaving
Ext1's 6.37 m² window NOT deducted from Ext1's wall — Ext1 wall area
inflated to 16.54 (gross) instead of 10.17 (net), then multiplied by
the lower U=0.26 → cascade understated walls_w_per_k by ~2.8 W/K.
Add `_window_bp_index` mapping `SapWindow.window_location` (int
from API mapper, "Main"/"Nth Extension" string from Elmhurst) to a
sap_building_parts index. Pre-compute per-bp window areas and use
that in the loop's `net_wall_area` calculation.
Backwards-compat preserved for direct callers passing
`window_total_area_m2` kwarg with an empty `epc.sap_windows` (legacy
single-bp test path): the kwarg total still apportions to Main.
Cohort hand-built fixtures default `window_location=0` so all windows
route to Main — same as the old i==0 logic for those tests.
Cascade behaviour changes for 3 golden certs with non-Main windows
(all 3 in the right direction — residuals tighten toward zero):
6035-7729: SAP -5 → -4, PE +36.15 → +34.02, CO2 +0.81 → +0.76
7536-3827: SAP +4 (same), PE -27.17 → -24.73, CO2 -0.72 → -0.66
8135-1728: SAP +1 (same), PE -16.98 → -16.51, CO2 -0.30 → -0.29
Pins tightened; notes annotated with slice attribution. Cert 001479
chain pin closes from delta 1.63 → 1.37 (cascade SAP 70.64 → 70.38,
target 69.0094) — remaining ~4.4 W/K HLC gap lives in floor U
defaults (Ext1 insulated "As Built") and Ext2 roof area derivation.
70 of 71 chain+golden+heat-transmission tests green; only the cert
001479 chain pin remains RED (load-bearing forcing function).
Pyright net-zero (13-error baseline on heat_transmission.py
preserved).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two coupled bugs surfaced by cert 001479's mains-gas-fire secondary
heating (Summary §14.1 lodges "SAP code 605, Flush fitting live effect
gas fire" → fuel 26 mains gas):
1. **Mapper**: `_map_elmhurst_sap_heating` only set
`secondary_heating_type` (the SAP code int) — `secondary_fuel_type`
stayed None. The Summary PDF doesn't lodge the fuel int separately;
it has to be derived from the SAP code range. Add
`_elmhurst_secondary_fuel_from_sap_code`: codes 601-630 → 26
(mains gas); other codes return None (the cascade defaults to
electric, matching cohort 000490 SAP code 691 electric panel).
2. **Cascade**: `_fuel_cost` in cert_to_inputs hardcoded
`secondary_high_rate_gbp_per_kwh = other_uses_gbp_per_kwh` (the
standard-electricity tariff) regardless of `secondary_fuel_type`.
For gas secondaries this charged 1846 kWh/yr at electric rate
(£0.132/kWh = £243) instead of gas rate (£0.0348/kWh = £64) —
a ~£175/yr ECF distortion ≈ 9 SAP points on cert 001479. Route
the cost through `table_32_unit_price_p_per_kwh(secondary_fuel)`
when lodged.
Worksheet line (242) confirms the gas pricing:
`Space heating - secondary 2025.93 3.4800 70.5022`
Cert 001479 chain pin delta narrows: SAP_continuous 61.39 → 70.64
(was −7.62 vs 69.0094, now +1.63 — overshooting target by 1.63 SAP).
The remaining overshoot maps to the cascade's ~16 W/K HLC undercount
(cascade HLP 2.89 vs worksheet 3.13 × TFA) — work for follow-up
slices.
Cohort 6 chain certs still green at 1e-4 (all-electric or no-
secondary). Golden cohort: cert 0300-2747 (mains-gas secondary)
SAP residual tightens −7 → +2 — biggest single SAP improvement on
the golden cohort to date; pin updated and notes annotated. Other
7 golden certs unchanged (None or electric secondary fuel). Pyright
net-zero (35 baseline each on mapper.py + cert_to_inputs.py).
Chain pin `test_summary_001479_full_chain_sap_matches_worksheet_pdf_
exactly` is the load-bearing RED — committed failing per TDD; closes
to GREEN once the HLC undercount lands.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Cert 001479 Ext2 §8 lodges:
Type: PS Pitched, sloping ceiling
Insulation: S Sloping ceiling insulation
Insulation Thickness: As Built
age C (1930-49)
The Summary's "As Built" thickness encodes "the dwelling as originally
constructed" — for pre-1950 sloping-ceiling roofs that's uninsulated
(no roof insulation in original 1930s construction). The worksheet's
§3 row pins U=2.30 (Table 16 row 0, uninsulated).
Pre-slice the mapper passed thickness=None through, routing to
`u_roof`'s Table 18 col 1 default (0.40 W/m²K for age C). That table
assumes joist insulation accessible from the loft — wrong geometry for
PS (Pitched, sloping ceiling) which has no loft access for retrofit.
Add `_resolve_sloping_ceiling_thickness`: when roof_type starts with
"PS" + lodged thickness is None + age ∈ {A,B,C,D} → thickness=0.
Other ages leave None (cascade default), matching Ext1's worksheet
U=0.15 at age M.
Cascade SAP 61.93 → 61.39 (−0.54, expected — uninsulated roof adds
heat loss); cohort 6 certs all green at 1e-4 (none have PS+age≤D);
pyright net-zero baseline preserved.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`_is_floor_exposed_to_unheated_space` previously only matched
"U Above unheated space" (semi-exposed floor over a porch / car-park).
Cert 001479 Ext2 §9 lodges "Location: E To external air" — a 1.92 m²
cantilevered exposed timber floor (the upper-storey extension hanging
out over the garden). The worksheet's §3 `Exposed floor Ext2 … 1.92,
1.20, 1.20` pins this surface as U=1.20 via Table 20.
Pre-slice the mapper missed the "external air" lodgement entirely;
`is_exposed_floor=False` routed Ext2's ground SapFloorDimension
through the BS EN ISO 13370 ground-floor cascade (default U≈0.5),
mis-modelling a fully-exposed cantilever as a slab on soil.
Both lodgement strings ("above unheated", "external air") now
trigger the Table 20 path. Function docstring updated; name kept
to minimise the diff (refactor candidate for a future slice).
Cohort 6 certs all still green at 1e-4 (none lodge external-air
floors); cert 001479 cascade SAP 61.90 → 61.93 (+0.03), modest
upward move toward the 69.0094 target.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`_ELMHURST_PARTY_WALL_CODE_TO_SAP10` only recognised the bare "C" and
"S" leading codes. Cert 001479 Main §7 lodges "Party Wall Type: CU
Cavity masonry unfilled" — the leading token is "CU", which fell
through to None and made `u_party_wall` apply the unknown-default
U=0.25 instead of the worksheet's lodged U=0.50.
Add "CU" → 4 (SAP10 WALL_CAVITY); `u_party_wall(4) = 0.5 W/m²K`
matches the worksheet's §3 `Party walls Main … 0.50` row exactly.
This widens the chain residual on cert 001479 (cascade SAP 63.17 →
61.90 vs target 69.0094) — not a regression: pre-slice the cascade
was UNDER-counting party-wall heat loss (U=0.25 vs the lodged 0.50),
which masked over-counting elsewhere. The party-wall U-value is now
worksheet-accurate; remaining 7.1 SAP gap will narrow as the other
mapper gaps (Ext2 exposed floor, roof insulation thickness, secondary
heating SAP code, etc.) land in follow-up slices.
All 10 chain tests green (6 cohort + 2 cert-001479 structural pins).
Pyright net-zero (35-error baseline preserved on mapper.py).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
`from_elmhurst_site_notes` hard-coded `extensions_count=0` regardless of
how many extensions the survey lodged. The 6 cohort certs from Slices
47-53 all happened to have 0-2 extensions whose count nothing
load-bearing read, so this latent bug was invisible. Cert 001479
(Summary_001479.pdf, GOV.UK EPB cert 0535-9020-6509-0821-6222) has Main
+ Extension 1 + Extension 2 and is the first cohort cert with a real
API counterpart — accurate `extensions_count` becomes load-bearing the
moment the cross-mapper parity assertion compares API vs Elmhurst
EpcPropertyData side by side.
No SAP-cascade impact (the cascade iterates `sap_building_parts`, not
`extensions_count`) — but a real data-integrity bug surfaced by the
cross-mapper diff. Adds Summary_001479.pdf as a new chain-test fixture
and `_SUMMARY_001479_PDF` constant for follow-up slices that will
land per-bp ages, exposed floors, secondary-heating SAP codes, etc.
All 9 chain tests green; 321 mapper/site-notes/rdsap tests green;
pyright net-zero (35-error baseline preserved on mapper.py).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
