S0380.197: simulated case 5 e2e fixture — detached sandstone RR validates S0380.196 (RdSAP 10 §3.9.1 + Table 4 p.22)

Promotes user-simulated "case 5" (detached, sandstone-walled, room-in-roof
cousin of golden cert 0240) to an e2e worksheet fixture pinning the WHOLE
extractor → mapper → calculator pipeline at abs=1e-4 on all 11 Block-1
line refs. Its worksheet prints the exact RR-gable routing S0380.196
implements, validating that fix against ground truth:

  Roof room Main Gable Wall 1  15.68  U=0.35  (29a)  Exposed → walls @ main-wall U
  Roof room Main remaining area 61.73  U=0.30  (30)  A_RR shell − Σ gables
  External roof Main           14.52  U=0.11  (30)  loft residual
  Roof room Main Gable Wall 2  15.68  U=0.25  (32)  Party → party @ 0.25

gable area = 6.40 × 2.45 (§3.9.1 default RR storey height); A_RR remaining
= 12.5√(83.2/1.5) − 2×15.68 = 93.09 − 31.36 = 61.73 (RdSAP 10 §3.9.1(e)).
Confirms a DETACHED dwelling can lodge a Party RR gable (Table 4 p.22
row 2) — so my S0380.196 mapping (gable_wall_type 0=Party, 1=Exposed) is
correct; do not flip it.

Two extractor/mapper gaps surfaced and fixed (case 5 is the forcing test):
- Sandstone wall label "SS Stone: sandstone or limestone" had no
  `_ELMHURST_WALL_CODE_TO_SAP10` entry (raised UnmappedElmhurstLabel).
  Added "SS" → 2 (WALL_STONE_SANDSTONE), matching 0240's API
  wall_construction=2 (cross-mapper parity).
- Roof "Insulation Thickness 400+ mm" was silently dropped: the four
  thickness parsers used `.split()[0].isdigit()`, which rejects the
  trailing "+" → None → u_roof fell back to the age-J default 0.16
  instead of 0.11 (+1.09 W/K roof, the whole 0.12 SAP gap). Added
  `_parse_thickness_mm` (strips to leading digits) and applied it at all
  four sites (walls / alt-wall / roof / floor). The only existing fixture
  with "400+ mm" (000565 Stud Wall) routes via the RIR regex, unaffected.

Result: case 5 cascade ≡ worksheet at 1e-4 on SAP/ECF/cost/CO2 + every
energy stream. Neither gap affects 0240 (its API path captures both the
sandstone code and "400mm+"); 0240's residual is therefore non-fabric.

Suite: 2353 passed, 1 skipped. New code: 0 pyright errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/documents_parser/elmhurst_extractor.py

@@ -281,11 +281,7 @@ class ElmhurstSiteNotesExtractor:
         # with the §8 Roofs / §9 Floors blocks. None when the PDF
         # omits the line (no retrofit lodged).
         ins_thickness_raw = self._local_val(lines, "Insulation Thickness")
-        insulation_thickness_mm = (
-            int(ins_thickness_raw.split()[0])
-            if ins_thickness_raw and ins_thickness_raw.split()[0].isdigit()
-            else None
-        )
+        insulation_thickness_mm = self._parse_thickness_mm(ins_thickness_raw)
         return WallDetails(
             wall_type=self._local_str(lines, "Type"),
             insulation=self._local_str(lines, "Insulation"),
@@ -323,11 +319,7 @@ class ElmhurstSiteNotesExtractor:
             if area <= 0:
                 continue
             thickness_raw = self._local_val(lines, f"Alternative Wall {n} Thickness")
-            thickness_mm = (
-                int(thickness_raw.split()[0])
-                if thickness_raw and thickness_raw.split()[0].isdigit()
-                else None
-            )
+            thickness_mm = self._parse_thickness_mm(thickness_raw)
             result.append(AlternativeWall(
                 area_m2=area,
                 wall_type=self._local_str(lines, f"Alternative Wall {n} Type"),
@@ -356,11 +348,25 @@ class ElmhurstSiteNotesExtractor:
         lines = [l.strip() for l in main_body.splitlines() if l.strip()]
         return self._wall_details_from_lines(lines)
 
+    @staticmethod
+    def _parse_thickness_mm(raw: Optional[str]) -> Optional[int]:
+        """Parse an Elmhurst "Insulation Thickness" cell ("100 mm",
+        "400+ mm") to integer mm. The bucket-cap "400+ mm" (Table 17/18
+        max tabulated row) carries a trailing "+" that a bare
+        `.split()[0].isdigit()` test rejects — strip to the leading
+        digits so the cap parses through to the cascade with its numeric
+        value (simulated case 5: roof "400+ mm" was silently dropped →
+        u_roof fell back to the age-J default 0.16 instead of the
+        300mm+ value 0.11). Returns None when the cell is absent or
+        carries no leading number ("As Built", "N None")."""
+        if not raw:
+            return None
+        match = re.match(r"\d+", raw.strip())
+        return int(match.group()) if match else None
+
     def _roof_details_from_lines(self, lines: List[str]) -> RoofDetails:
         thickness_raw = self._local_val(lines, "Insulation Thickness")
-        thickness_mm = (
-            int(thickness_raw.split()[0]) if thickness_raw and thickness_raw.split()[0].isdigit() else None
-        )
+        thickness_mm = self._parse_thickness_mm(thickness_raw)
         insulation = self._local_str(lines, "Insulation")
         # The Summary PDF omits the "Insulation Thickness" line entirely
         # when no retrofit insulation is lodged (e.g. "Insulation: N None"
@@ -391,11 +397,7 @@ class ElmhurstSiteNotesExtractor:
         # via the per-thickness column. Mirror of the §8 roof extractor
         # at `_roof_details_from_lines`.
         thickness_raw = self._local_val(lines, "Insulation Thickness")
-        thickness_mm = (
-            int(thickness_raw.split()[0])
-            if thickness_raw and thickness_raw.split()[0].isdigit()
-            else None
-        )
+        thickness_mm = self._parse_thickness_mm(thickness_raw)
         return FloorDetails(
             location=self._local_str(lines, "Location"),
             floor_type=self._local_str(lines, "Type"),

datatypes/epc/domain/mapper.py

@@ -2090,6 +2090,10 @@ _ELMHURST_WALL_CODE_TO_SAP10: Dict[str, int] = {
     "SG": 1,   # Stone: granite or whinstone (cert 000565 Ext1) — the
                # granite-specific Elmhurst variant of "ST"; same SAP10
                # WALL_STONE_GRANITE=1 cascade entry.
+    "SS": 2,   # Stone: sandstone or limestone (simulated case 5 / cert
+               # 0240 archetype) — SAP10 WALL_STONE_SANDSTONE=2. The
+               # sandstone-specific Elmhurst variant; the API path lodges
+               # the same wall as integer wall_construction=2.
     "SB": 3,   # Solid brick (cohort cert lodgement)
     "SO": 3,   # Solid brick (newer Elmhurst PDF variant — same SAP10
                # mapping; cert 9501 lodges "SO Solid Brick" where the

tests/domain/sap10_calculator/worksheet/_elmhurst_worksheet_001431_case5.py

@@ -0,0 +1,122 @@
+"""Mapper-driven cascade pin against the Elmhurst P960-0001-001431
+"simulated case 5" worksheet — a DETACHED, SANDSTONE-walled cousin of
+golden cert 0240 (Main + Extension + room-in-roof, age band J).
+
+Like the other 001431 cases, this fixture does NOT hand-build the
+EpcPropertyData: it routes the Summary PDF through
+ElmhurstSiteNotesExtractor + from_elmhurst_site_notes so the SAP-result
+pin grid exercises the WHOLE extractor + mapper + calculator pipeline.
+
+Purpose: prove the calculator is spec-correct for a DETACHED room-in-roof
+with one Exposed + one Party gable, validating S0380.196 (API Simplified
+Type 1 RR gables deduct from the A_RR shell) against a real worksheet.
+The worksheet prints the exact routing the cascade implements:
+
+  Roof room Main Gable Wall 1  15.68  U=0.35  (29a)  ← Exposed → walls @ main-wall U
+  Roof room Main remaining area 61.73  U=0.30  (30)  ← A_RR shell − Σ gables (residual)
+  External roof Main           14.52  U=0.11  (30)  ← loft residual
+  Roof room Main Gable Wall 2  15.68  U=0.25  (32)  ← Party → party @ 0.25
+
+gable area = 6.40 × 2.45 = 15.68 m² (the §3.9.1 default RR storey height).
+A_RR remaining = 12.5√(83.2/1.5) − 2×15.68 = 93.09 − 31.36 = 61.73.
+
+This case surfaced two extractor/mapper gaps fixed in the same slice
+(S0380.197):
+- the sandstone wall label "SS Stone: sandstone or limestone" had no
+  `_ELMHURST_WALL_CODE_TO_SAP10` entry (→ WALL_STONE_SANDSTONE=2, matching
+  0240's API `wall_construction=2`);
+- the roof "Insulation Thickness 400+ mm" was silently dropped by the
+  extractor's `.split()[0].isdigit()` thickness parse (the trailing "+"),
+  so u_roof fell back to the age-J default 0.16 instead of 0.11
+  (`_parse_thickness_mm` now strips to leading digits).
+
+Cert shape: Detached house, Main + Extension 1, sandstone insulated walls,
+2 storeys + room-in-roof on the Main (floor 83.2 m², one Exposed + one
+Party gable, L=6.40 each), oil community/boiler (SAP code 901 combi route,
+control 2106), no PV, 20 low-energy lighting bulbs.
+
+Source: user-simulated PDFs at `sap worksheets/golden fixture
+debugging/simulated case 5/`. The Summary is mirrored into the tracked
+`backend/documents_parser/tests/fixtures/Summary_001431_case5.pdf`.
+
+Worksheet pin targets (P960-0001-001431, Block 1 — energy rating):
+- SAP rating 61 (line 258), ECF 2.7724 (line 257)
+- Total fuel cost £1586.4549 (line 255)
+- CO2 8387.6229 kg/year (line 272)
+- Space heating 12838.6489 kWh/year (Σ monthly (98))
+- Main 1 fuel 21397.7480 kWh/year (line 211)
+- Secondary fuel 0.0 (line 215)
+- Hot water fuel 6498.2518 kWh/year (line 219)
+- Lighting 381.4601 kWh/year (line 232)
+- Pumps/fans 141.0 kWh/year (line 231)
+
+Per [[feedback-zero-error-strict]] + [[feedback-e2e-validation-
+philosophy]]: pins are abs=1e-4 against the worksheet PDF.
+"""
+
+from __future__ import annotations
+
+import re
+import subprocess
+from pathlib import Path
+from typing import Final
+
+from backend.documents_parser.elmhurst_extractor import ElmhurstSiteNotesExtractor
+from datatypes.epc.domain.epc_property_data import EpcPropertyData
+from datatypes.epc.domain.mapper import EpcPropertyDataMapper
+
+
+# parents[0]=worksheet/, [1]=sap10_calculator/, [2]=domain/, [3]=tests/,
+# [4]=repo root.
+_SUMMARY_PDF: Final[Path] = (
+    Path(__file__).resolve().parents[4]
+    / "backend" / "documents_parser" / "tests" / "fixtures"
+    / "Summary_001431_case5.pdf"
+)
+
+
+def _summary_pdf_to_textract_style_pages(pdf_path: Path) -> list[str]:
+    """Convert a Summary PDF into the per-page text format the
+    ElmhurstSiteNotesExtractor expects (label\\nvalue sequences).
+
+    Mirror of the helper in `test_summary_pdf_mapper_chain.py` /
+    `_elmhurst_worksheet_000565.py`.
+    """
+    info = subprocess.run(
+        ["pdfinfo", str(pdf_path)], capture_output=True, text=True, check=True,
+    ).stdout
+    m = re.search(r"Pages:\s+(\d+)", info)
+    if m is None:
+        raise RuntimeError(f"Could not parse page count from {pdf_path}")
+    page_count = int(m.group(1))
+
+    pages: list[str] = []
+    for i in range(1, page_count + 1):
+        layout = subprocess.run(
+            [
+                "pdftotext", "-layout", "-f", str(i), "-l", str(i),
+                str(pdf_path), "-",
+            ],
+            capture_output=True, text=True, check=True,
+        ).stdout
+        tokens: list[str] = []
+        for line in layout.splitlines():
+            if not line.strip():
+                tokens.append("")
+                continue
+            parts = [p for p in re.split(r"\s{2,}", line.strip()) if p]
+            tokens.extend(parts)
+        pages.append("\n".join(tokens))
+    return pages
+
+
+def build_epc() -> EpcPropertyData:
+    """Route the simulated case-5 Summary through extractor + mapper.
+
+    No hand-built EpcPropertyData — the extractor and mapper are part of
+    the test target. Exercises the S0380.196 RR-gable deduction, the
+    S0380.197 sandstone-wall-label + "400+ mm" roof-thickness fixes.
+    """
+    pages = _summary_pdf_to_textract_style_pages(_SUMMARY_PDF)
+    site_notes = ElmhurstSiteNotesExtractor(pages).extract()
+    return EpcPropertyDataMapper.from_elmhurst_site_notes(site_notes)

tests/domain/sap10_calculator/worksheet/test_e2e_elmhurst_sap_score.py

@@ -41,6 +41,7 @@ from tests.domain.sap10_calculator.worksheet import (
     _elmhurst_worksheet_001431_rr as _w001431_rr,
     _elmhurst_worksheet_001431_rr8 as _w001431_rr8,
     _elmhurst_worksheet_001431_6035 as _w001431_6035,
+    _elmhurst_worksheet_001431_case5 as _w001431_case5,
 )
 from tests.domain.sap10_calculator.worksheet._elmhurst_fixtures import (
     ALL_FIXTURES as _ELMHURST_FIXTURES,
@@ -217,6 +218,25 @@ _FIXTURE_PINS: Final[dict[str, FixtureCascadePins]] = {
         lighting_kwh_per_yr=262.0885,
         pumps_fans_kwh_per_yr=86.0,
     ),
+    # Mapper-driven cohort entry — Summary_001431_case5.pdf → extractor →
+    # mapper → calculator. DETACHED, SANDSTONE-walled cousin of cert 0240:
+    # Main + Extension + room-in-roof (floor 83.2 m², one Exposed + one
+    # Party gable L=6.40), age J, oil combi (SAP 901), no PV. Validates
+    # S0380.196 (RR gable deduction) against a real worksheet — the
+    # worksheet prints Gable 1 (Exposed) at (29a) U=0.35, Gable 2 (Party)
+    # at (32) U=0.25, remaining area = shell − Σ gables at (30). Also pins
+    # the S0380.197 sandstone "SS" wall label + "400+ mm" roof-thickness
+    # extractor fixes (without the latter, roof U fell to 0.16 not 0.11).
+    "001431_case5": FixtureCascadePins(
+        sap_score=61, sap_score_continuous=61.3255, ecf=2.7724,
+        total_fuel_cost_gbp=1586.4549, co2_kg_per_yr=8387.6229,
+        space_heating_kwh_per_yr=12838.6489,
+        main_heating_fuel_kwh_per_yr=21397.7480,
+        secondary_heating_fuel_kwh_per_yr=0.0,
+        hot_water_kwh_per_yr=6498.2518,
+        lighting_kwh_per_yr=381.4601,
+        pumps_fans_kwh_per_yr=141.0,
+    ),
 }
 
 
@@ -232,6 +252,7 @@ _FIXTURE_MODULES: Final[dict[str, ModuleType]] = {
     "001431_rr": _w001431_rr,
     "001431_rr8": _w001431_rr8,
     "001431_6035": _w001431_6035,
+    "001431_case5": _w001431_case5,
 }