Golden cert 0330 now reaches band C on the dwelling-sized ASHP alone
(ADR-0049), dropping its solid_floor_insulation companion; cert 0390
still fires three measures, so the per-measure trigger-attribute
assertions move there (and gain the lighting triggers).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`from_sap_schema_17_1` hardcoded is_dwelling_export_capable=False, so
SAP 10.2 Appendix M1 zeroed the PV export credit on every export-capable
full-SAP cert. Cert 0380-3044-6070-2305-5925 (property 741840, PRD #1435
WS3) now reproduces its lodged 92 exactly (was 89); the existing
19.1.0 pin 10096028301 closes its documented -1 residual (84 -> 85 =
lodged). The full-SAP top-level pv_connection is deliberately NOT
carried: its enum disagrees with the RdSAP one the calculator gates on.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Regression guard: category 8 + control 2701 keep the ADR-0048 coherence
invariant satisfied for SAP codes 421/422/424.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Sizing selects the aroTHERM plus rung nearest PSR ~0.8 (0.8 x design heat
loss) — the Appendix-N efficiency peak, reproducing the pump a real
installer fits — rather than the MCS PSR>=1.0 capacity target, which
oversizes. Validated against the relodged Elmhurst ASHP cert (delta 0
held at the 5 kW Vaillant); the two self-snapshot pins re-pin to their
correctly-sized larger pumps, and the orchestrator/harness thread the
calculator's design heat loss so production sizes to the dwelling. Manual
SapResult test stubs carry the new design_heat_loss_kw field.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
_ashp_option now selects the aroTHERM plus PCDB record matching the
threaded design heat loss (floor-area proxy fallback), so the overlay's
efficiency anchor is sized to the dwelling instead of a fixed 5 kW unit.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Walked the water-heating worksheet section: assumed occupancy (42) matched
exactly (2.4234 both sides), but (43) average daily hot water use was
117.41 L/day (Elmhurst) vs 110.73 L/day (ours) — same occupancy, different
shower/bath demand. Root cause: the cert's shower_outlets field is
genuinely unlodged, which the mapper correctly maps to 0 mixer showers
per its documented, already-validated "no entry = no shower" convention.
Elmhurst's build shows a "Non-electric shower" fixture anyway — its UI
silently defaults one when the build script doesn't explicitly configure
"0 showers" to match the cert.
Verified: a single 7 L/min vented mixer reproduces Elmhurst's (42a)
monthly series exactly (4 d.p., all 12 months) and closes hot water to
2616.04 vs Elmhurst's 2616.03. Corpus-wide check across 170 certs sharing
this "bath present, no shower data" pattern shows no systematic bias
(mean dSAP +0.12, median -0.04) — confirms the mapper convention is
correct on average; this is a build-entry artifact on this one cert, not
a mapper bug (no code change warranted).
Combining all three found causes (window orientation, Table 11, shower
default): SAP 72.4567 vs Elmhurst's precise 72.0681 — residual 0.39,
~91% of the original 4.26-point gap now precisely explained.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Walked the worksheet section-by-section (dimensions, ventilation, fabric,
internal/solar gains, MIT, space-heating requirement, fuel cost) against
the calculator's matching intermediates. Internal gains and heat loss
matched closely, but solar gains (worksheet line 83) was 2.2x off in
January (56.9 W vs our 123.4 W) — traced to the Elmhurst BUILD entering
all 12 real windows (3 orientations: NW 7.05 m2, NE 1.21 m2, SE 7.06 m2)
as a single synthetic 15.32 m2 "North" group, understating solar gain.
Verified by reproducing both build artifacts in the calculator: real
windows + real Table-11 gating = 76.33 (our answer, matches lodged 76
exactly); collapsing to a synthetic single-North window + forcing Table
11 on = 72.62, reproducing Elmhurst's 72 almost exactly. Confirms neither
residual is a mapping or calculator bug — one is a deliberate,
regression-tested spec choice (Table 11) and the other is an artifact of
how this specific Elmhurst reconciliation build was entered.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The prior comment blamed a stale build-side combi artifact (already fixed
this session) and my earlier conversational claim that Elmhurst's overall
SAP used regional weather was wrong too — verified the worksheet's (5)
dwelling volume and wind table match our UK-average rating cascade exactly.
The actual, now-quantified driver: Elmhurst's worksheet (201)/(202)/(215)
show it unconditionally applies SAP 10.2 Table 11's 10% secondary/portable-
electric-heater fraction based on main heating category alone, with no
secondary lodged on the cert. Our `_secondary_fraction` deliberately gates
this on an actual lodged/forced secondary (see the adjacent S-B30 note:
applying it unconditionally regressed the full 1000-cert corpus MAE by
+0.16). Forcing Table 11 on for just this cert moves 76.33 -> 73.62 (~62%
of the 76.33-vs-72 gap) — confirms this, not a mapping error, drives the
residual. Documented so the next reader doesn't re-litigate it.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
_has_suspended_timber_floor_per_spec only read the Main bp's per-part
floor_construction_type lodgement; the gov-API mapper frequently leaves
that None even when the global epc.floors[].description carries an
explicit "Suspended, ..." observation. _main_floor_u_value already fell
back to this joined description for the U-value calc — the infiltration
rule did not, so a genuinely suspended-timber floor silently entered
(12)=0 instead of 0.2 unsealed. Extracted the shared
_effective_floor_description helper and added a tri-state resolver
(explicit lodgement -> description, excluding "not timber" -> Table 19
footnote-1 age-A/B default) so both paths agree.
Cert 100061275133 (Elmhurst-validated build, PR #1439 handoff): engine
77.24 -> 76.33, now an exact match to lodged (76). Corpus gauge 77.7% ->
77.8% within-0.5, MAE 0.637 -> 0.636; floors ratcheted.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Electric-tariff cluster investigation. The 112-cert electric-main cohort is
mixed-sign within every category/meter - no systematic tariff bias. Root cause
of the biggest non-xfail divergences (10012334488 +13.2, 10091578598 +7.81):
SAP code 195 = 'Electric water storage boiler' (Table 4a p.170), which SAP 10.2
§12 Rule 2 correctly bills mostly at the 7-hour off-peak rate. Both are pure
cost gaps (PE/CO2 match lodged -> demand right); the lodged software over-billed
the storage boilers at peak rate. The engine is SPEC-FAITHFUL - matching lodged
would tune against §12/Table-4a. Pinned to the spec-faithful engine values.
Adds scripts/corpus_1000/elec_cohort.py (electric-main cohort analyzer).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Final two clean single-main gas certs. Both small cost-side residuals (+1.04 /
-1.01 SAP) on cavity-insulated fabric already Elmhurst-validated on sibling
certs, with properly-insulated cylinders (insulation type 1, 50/80mm - not the
type-0/NULL zero-storage-loss bug). No fabric anomaly; the register data fully
explains the engine output. Pinned to observed engine 71 / 79.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2-storey semi, solid brick 400mm with EXTERNAL insulation, 300mm loft,
suspended uninsulated ground floor, gas combi, double glazing (glazed_type 13).
Built in accredited Elmhurst RdSAP10: roof (U 0.14, 5.459 W/K) and windows
(15.32 x eff U 1.3258 = 20.311 W/K) match the engine EXACTLY; the
externally-insulated wall is engine U 0.29 vs Elmhurst 0.30, validating the
slice-5 external-insulation default (100mm added over solid brick); suspended
ground floor engine 0.68 vs Elmhurst 0.70. Elmhurst's overall SAP 67 is not
comparable (reused-assessment Standard-Combi keep-hot loss, a build artifact).
Engine 77 vs lodged 76 (within 1.24). Pinned to the observed 77.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Top-floor flat, solid brick uninsulated, uninsulated flat roof, gas combi,
SINGLE glazing (glazed_type 5). Built in accredited Elmhurst RdSAP10 and every
heat-loss element matches the engine EXACTLY: walls 53.18, flat roof 145.57,
floor 0, party 0, and — with the faithful single glazing — windows 34.7114 W/K
(8.62 m2 x eff U 4.0268). Confirms the mapper's glazed_type 5 -> single (raw U
4.8) is spec-correct per epc_codes.csv, not the double it superficially
resembles. Engine 61 vs lodged 62; the -1.18 is a cost-side residual, not a
fabric bug. Pinned to the observed engine 61.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SOLVED the window-grid blocker (per Junte's "keep one and edit, don't
delete all"): set_single_window now ADDS the fresh window (it inserts at
DOM index 0), then deletes the STALE rows BELOW it by index (high->low,
never index 0) via the per-row Delete image button + JS-clicked Yes modal.
The freshly-added row survives as the single window; no 0.00 junk strands
to block the Recommendations gate. Verified end-to-end: cert 100050881708
built, worksheet downloaded, walls (0.70) + roof (0.19) match the engine
EXACTLY. Combined with the earlier fill+Tab (area postback) + frame/gap
(validation) fixes, the per-cert loop now runs autonomously on clean
single-main certs.
Pin: 100050881708 (semi, cavity filled, pitched 225mm, suspended ground
floor, combi) engine 72 = lodged 70 +2; walls/roof accredited-Elmhurst-
matched. NB the build entered the suspended ground floor as an upper
"above unheated space" floor, so Elmhurst's worksheet SAP (61) is not a
clean comparison — the engine uses the correct §3.12 suspended-ground U
(0.74); the pin rests on the walls+roof match + lodged.
No engine change.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
A FLAT roof lodges its insulation thickness in the DEDICATED gov-EPC API
`flat_roof_insulation_thickness` field (e.g. "75mm"), leaving
`roof_insulation_thickness` None (that field is for pitched-loft joists).
`heat_transmission_from_cert` read only the latter, so a measured
flat-roof thickness was ignored and the roof billed at the uninsulated
age-band flat default (age E = 1.5) instead of its Table-16 insulated U.
Fixed by preferring `flat_roof_insulation_thickness` when the part is a
flat roof — the exact mirror of the existing rafter-thickness branch.
An "AB"/"NI" (as-built/unknown) value parses to None and keeps the
age-band default, unchanged; only measured thicknesses move.
PER-CERT ELMHURST VALIDATION (cert 47084930, top-floor flat, flat roof
75 mm): built on the lodged inputs in accredited Elmhurst RdSAP10-Online
(evidence saved: elmhurst_summary.pdf / elmhurst_worksheet.pdf). The
worksheet bills "insulated flat roof" at U 0.5 (floor 0.70 + wall 0.25
also matching the engine). The fix takes the engine roof 96.4 -> 32.1 W/K
(= 64.26 x 0.5, Elmhurst-exact), PE +47 -> +0.2, SAP 69.51 -> 74.34 =
lodged 74.
Gauge: within 77.3% -> 77.7%, SAP MAE 0.648 -> 0.641, CO2 0.074 -> 0.072,
PE 3.1 -> 2.97. Unit-pinned in test_heat_transmission
(flat_roof_insulation_thickness -> U 0.5); RealCertExpectation 47084930
= 74 (Elmhurst-validated). Also adds the build script build_47084930.py.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
A hot-water cylinder lodging gov-API `cylinder_size=0` ("size not
determined", with has_hot_water_cylinder=true) resolved to a None volume
in `_cylinder_storage_loss_override` (which reads `_cylinder_volume_l_
from_code`, returning None for code 0). The subsequent `if volume_l is
None: return None` then DROPPED the cylinder's Table-2 storage loss
entirely — under-costing the DHW and over-rating the dwelling. Meanwhile
the Table-13 high-rate-fraction path already used `_hot_water_cylinder_
volume_l` (which defaults size 0 to 110 L), so the two DHW paths
disagreed on the same cylinder.
RdSAP 10 §10.5 Table 28 ("if the actual size is not determined, the size
is taken as according to Table 28") makes an unsized present cylinder the
110 L "Normal" baseline, which STILL incurs the storage loss. Fixed by
defaulting the storage-loss volume to 110 L for the explicit size-0 case.
Gated on the EXPLICIT 0 (not None): a full-SAP cert whose RdSAP
cylinder_size is simply unlodged (None, e.g. pinned 10091568921) keeps
its own cylinder handling rather than a forced 110 L RdSAP default.
7 corpus certs lodge cylinder_size=0 + has_cylinder=true. Gauge: within
77.0% -> 77.3%, SAP MAE ~flat (0.648), CO2 0.074 -> 0.073, PE 3.2 -> 3.05
(the previously-dropped storage loss now correctly counted in the demand
cascade). Unit-pinned in test_cert_to_inputs (storage loss non-None for
size 0); RealCertExpectation 200004017091 = 71.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
A SOLID-BRICK or STONE wall lodging External/Internal insulation
(wall_insulation_type 1/3) but no measured insulation thickness (gov-API
"NI" -> None) was billed at its UNINSULATED §5.6/Table-6 U-value: the §5.8
added-insulation R-value adjustment gates on `insulation_thickness_mm > 0`,
so an unknown thickness fell straight through to the raw solid-wall U
(~1.4-1.7). This over-counted wall heat loss and under-rated the dwelling.
RdSAP 10 §5.4 (PDF p.32): "the U-value with additional insulation is based
on the thickness of insulation of mineral wool type (assume 100 mm if
thickness is unknown)". Apply that 100 mm default so the §5.8 Table-14
R-value fires. Scoped to solid brick / stone (the only constructions with
a §5.8 R-value path in u_wall) so cavity (composite path) and timber /
system-built walls are untouched.
Localised by deep-diving corpus cert 200004296092 (end-terrace, solid
brick 360 mm "with external insulation", NI): walls 101.7 W/K (U~1.40,
HLP 3.46 = absurd for an insulated wall) -> ~0.29; PE +59.6 -> ~0; engine
64.35 (Δ -6.65) -> 71.74 = lodged 71. ~8 solid-brick/stone corpus certs
carry this NI-thickness-with-insulation shape.
Gauge: within-0.5 held at 77.0%, SAP MAE 0.658 -> 0.647, CO2 0.074 ->
0.073, PE 3.2 -> 3.1 (floor ratcheted). Unit-pinned in test_rdsap_uvalues
(brick 360 mm external NI -> 0.29) + RealCertExpectation 200004296092 = 72.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
An instantaneous point-of-use electric water heater (WHC 907/909, no
cylinder) on an off-peak tariff was billed 100% at the off-peak LOW rate
by the generic electric-off-peak else-branch. But SAP 10.2 §12 (PDF line
2680) computes the off-peak on-peak HW proportion via Table 13, "dependent
on the total floor area and the CYLINDER size" — it presumes a stored-water
cylinder charged overnight. An instantaneous heater has NO cylinder, heats
on demand, and cannot shift to the off-peak window, so 100% of its
consumption bills at the HIGH rate (Table 12a WH high-rate fraction 1.0).
Both the SAP-cost rate (`_hot_water_fuel_cost_gbp_per_kwh`) and the
ADR-0014 / CO2-PE fraction (`_hot_water_high_rate_fraction`) fixed
consistently (low-rate scalar -> 7-hour high rate; fraction 0.0 -> 1.0).
Localised by deep-diving corpus cert 74061136 (HHR-storage mid-floor flat,
WHC 909): PE matched lodged (+1.6, roof+floor zero-loss) while SAP over-rated
+7.72 — the cost-only signature. Its DHW was ours £59 vs lodged £344 (5.8x);
the tariff was the whole gap. Fix: +7.72 -> -1.25 (residual is separate small
fabric). 7 corpus certs carry electric-instantaneous DHW on off-peak; the 3
outside 0.5 all move sharply inward (MAE the win, not within-0.5 crossings).
RdSAP 10 §12 tariff routing confirmed spec-correct (Unknown meter + storage
409 -> off-peak 7-hour, Rule 2) — the bug was the DHW rate, not the tariff.
Unit-pinned in test_cert_to_inputs; RealCertExpectation 74061136 = 72.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The gov-API `secondary_fuel_type` enums 5 (anthracite) / 9 (dual fuel) /
33 (coal) collide in VALUE with same-valued RdSAP-10 Table-32 codes for
OTHER fuels (5=bulk LPG, 9=LPG SC11F, 33=elec 10h-low). The main-fuel
boundary and the CO2/display `_secondary_fuel_cost_gbp_per_kwh` already
canonicalise these via `canonical_fuel_code`, but the SAP-DRIVING
`_fuel_cost` cascade had a SEPARATE inline secondary rate that passed the
raw enum straight to the price lookup — so the two paths diverged and the
cost path silently mis-priced.
Anthracite (enum 5) was billed at the bulk-LPG code-5 rate 12.19 p/kWh
instead of 3.64 — a 3x over-cost on the secondary that under-rated every
solid-fuel-secondary dwelling. Worst: corpus cert 100050355518 (semi,
2 extensions, anthracite room-heater secondary) lodged 36 / engine 20.8
-> 35.5. Its CO2/PE already matched lodged (the demand cascade was right)
— a pure cost-side gap, which is what localised it.
Fix: canonicalise `secondary_fuel` before the Table-32 lookup in
`_fuel_cost`, mirroring the main-fuel boundary. 55 corpus certs carry a
colliding secondary.
Gauge: within-0.5 75.5% -> 77.0%, SAP MAE 0.708 -> 0.668 (floors
ratcheted). The prior enum-9 test only guarded the display helper; new
test_fuel_cost_secondary_colliding_fuel_priced_at_canonical_rate pins the
_fuel_cost cost path directly. RealCertExpectation pinned for
100050355518 (36 = lodged).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
