diff --git a/backend/documents_parser/tests/fixtures/Summary_000898.pdf b/backend/documents_parser/tests/fixtures/Summary_000898.pdf
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diff --git a/backend/documents_parser/tests/fixtures/Summary_000900.pdf b/backend/documents_parser/tests/fixtures/Summary_000900.pdf
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index 00000000..7f3dcda8
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diff --git a/backend/documents_parser/tests/fixtures/Summary_000901.pdf b/backend/documents_parser/tests/fixtures/Summary_000901.pdf
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diff --git a/backend/documents_parser/tests/fixtures/Summary_000902.pdf b/backend/documents_parser/tests/fixtures/Summary_000902.pdf
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diff --git a/backend/documents_parser/tests/fixtures/Summary_000904.pdf b/backend/documents_parser/tests/fixtures/Summary_000904.pdf
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diff --git a/backend/documents_parser/tests/test_summary_pdf_mapper_chain.py b/backend/documents_parser/tests/test_summary_pdf_mapper_chain.py
index 4f402e68..e4113edb 100644
--- a/backend/documents_parser/tests/test_summary_pdf_mapper_chain.py
+++ b/backend/documents_parser/tests/test_summary_pdf_mapper_chain.py
@@ -60,6 +60,8 @@ _SUMMARY_000897_PDF = _FIXTURES / "Summary_000897.pdf"
 _SUMMARY_000784_PDF = _FIXTURES / "Summary_000784.pdf"
 _SUMMARY_000899_PDF = _FIXTURES / "Summary_000899.pdf"
 _SUMMARY_000903_PDF = _FIXTURES / "Summary_000903.pdf"
+_SUMMARY_000901_PDF = _FIXTURES / "Summary_000901.pdf"  # cert 3800
+_SUMMARY_000904_PDF = _FIXTURES / "Summary_000904.pdf"  # cert 9285
 
 # GOV.UK EPB API JSON for cert 001479 — the API-path counterpart of the
 # Summary_001479.pdf fixture. Together they drive the API ≡ Summary
@@ -711,6 +713,53 @@ def test_summary_0350_full_chain_sap_within_spec_floor_of_worksheet() -> None:
     assert abs(result.sap_score_continuous - worksheet_unrounded_sap) < _ASHP_COHORT_CHAIN_TOLERANCE
 
 
+def test_summary_3800_full_chain_sap_within_spec_floor_of_worksheet() -> None:
+    # Arrange — cert 3800-8515-0922-3398-3563 (Summary_000901.pdf /
+    # dr87-0001-000901.pdf) is the third ASHP cohort cert to close on
+    # the Summary path: Mitsubishi PUZ-WM50VHA ASHP (PCDB 104568).
+    # Worksheet "SAP value" lodges 86.1458.
+    #
+    # **First-try closure — zero new mapper slices required**. The
+    # structural work shipped in slices S0380.2..S0380.9 (HP routing,
+    # cylinder block, composite walls, multi-array PV, extension
+    # inheritance) was already sufficient for cert 3800's variant set.
+    # Strong evidence that the Summary mapper has reached completeness
+    # for the standard single-bp / single-array ASHP shape.
+    pages = _summary_pdf_to_textract_style_pages(_SUMMARY_000901_PDF)
+    site_notes = ElmhurstSiteNotesExtractor(pages).extract()
+    epc = EpcPropertyDataMapper.from_elmhurst_site_notes(site_notes)
+
+    # Act
+    result = calculate_sap_from_inputs(
+        cert_to_inputs(epc, prices=SAP_10_2_SPEC_PRICES)
+    )
+
+    # Assert — ±0.07 ASHP-cohort spec-floor tolerance.
+    worksheet_unrounded_sap = 86.1458
+    assert abs(result.sap_score_continuous - worksheet_unrounded_sap) < _ASHP_COHORT_CHAIN_TOLERANCE
+
+
+def test_summary_9285_full_chain_sap_within_spec_floor_of_worksheet() -> None:
+    # Arrange — cert 9285-3062-0205-7766-7200 (Summary_000904.pdf /
+    # dr87-0001-000904.pdf) is the fourth ASHP cohort cert to close on
+    # the Summary path: Mitsubishi PUZ-WM50VHA ASHP (PCDB 104568).
+    # Worksheet "SAP value" lodges 84.1369. Same "first-try closure,
+    # zero new slices" disposition as cert 3800 — the cohort's
+    # structural mapper completeness is the load-bearing claim.
+    pages = _summary_pdf_to_textract_style_pages(_SUMMARY_000904_PDF)
+    site_notes = ElmhurstSiteNotesExtractor(pages).extract()
+    epc = EpcPropertyDataMapper.from_elmhurst_site_notes(site_notes)
+
+    # Act
+    result = calculate_sap_from_inputs(
+        cert_to_inputs(epc, prices=SAP_10_2_SPEC_PRICES)
+    )
+
+    # Assert — ±0.07 ASHP-cohort spec-floor tolerance.
+    worksheet_unrounded_sap = 84.1369
+    assert abs(result.sap_score_continuous - worksheet_unrounded_sap) < _ASHP_COHORT_CHAIN_TOLERANCE
+
+
 def test_summary_0380_full_chain_sap_within_spec_floor_of_worksheet() -> None:
     # Arrange — cert 0380-2471-3250-2596-8761 (Summary_000899.pdf /
     # dr87-0001-000899.pdf) is the first heat-pump cert under per-cert