diff --git a/scripts/dive_cert.py b/scripts/dive_cert.py
index 6fa83efb..8d6da1b4 100644
--- a/scripts/dive_cert.py
+++ b/scripts/dive_cert.py
@@ -17,6 +17,7 @@ from datatypes.epc.domain.mapper import EpcPropertyDataMapper
 from domain.sap10_calculator.calculator import calculate_sap_from_inputs
 from domain.sap10_calculator.rdsap.cert_to_inputs import (
     SAP_10_2_SPEC_PRICES,
+    cert_to_demand_inputs,
     cert_to_inputs,
 )
 from scripts.profile_api_error import features
@@ -40,6 +41,10 @@ def _dump(doc: dict[str, Any]) -> None:
     lodged_pe = doc.get("energy_consumption_current")
     epc = EpcPropertyDataMapper.from_api_response(doc)
     r = calculate_sap_from_inputs(cert_to_inputs(epc, prices=SAP_10_2_SPEC_PRICES))
+    # SAP/EI rating is the UK-average rating cascade (`r`); EPC CO2/PE use the
+    # postcode demand cascade (SAP 10.2 Appendix U p.124). Display CO2/PE from
+    # the demand cascade so they compare like-for-like with the lodged EPC.
+    d = calculate_sap_from_inputs(cert_to_demand_inputs(epc, prices=SAP_10_2_SPEC_PRICES))
     print("=" * 90)
     print(f"CERT {cert}")
     print(
@@ -48,13 +53,13 @@ def _dump(doc: dict[str, Any]) -> None:
     )
     if lodged_co2 is not None:
         print(
-            f"  CO2  lodged={lodged_co2:.3f}  ours={r.co2_kg_per_yr / 1000:.3f} t  "
-            f"d={r.co2_kg_per_yr / 1000 - lodged_co2:+.3f}"
+            f"  CO2  lodged={lodged_co2:.3f}  ours={d.co2_kg_per_yr / 1000:.3f} t  "
+            f"d={d.co2_kg_per_yr / 1000 - lodged_co2:+.3f}  (demand cascade)"
         )
     if lodged_pe is not None:
         print(
-            f"  PE   lodged={lodged_pe:.1f}  ours={r.primary_energy_kwh_per_m2:.1f}  "
-            f"d={r.primary_energy_kwh_per_m2 - lodged_pe:+.1f} kWh/m2"
+            f"  PE   lodged={lodged_pe:.1f}  ours={d.primary_energy_kwh_per_m2:.1f}  "
+            f"d={d.primary_energy_kwh_per_m2 - lodged_pe:+.1f} kWh/m2  (demand cascade)"
         )
     print(
         f"  energy kWh/yr: spaceheat={r.space_heating_kwh_per_yr:.0f} "
diff --git a/scripts/profile_corpus_error.py b/scripts/profile_corpus_error.py
index 851086a9..6ef2c4e6 100644
--- a/scripts/profile_corpus_error.py
+++ b/scripts/profile_corpus_error.py
@@ -37,6 +37,7 @@ from typing import Any, Optional
 from datatypes.epc.domain.mapper import EpcPropertyDataMapper
 from domain.sap10_calculator.calculator import calculate_sap_from_inputs
 from domain.sap10_calculator.rdsap.cert_to_inputs import (
+    cert_to_demand_inputs,
     SAP_10_2_SPEC_PRICES,
     cert_to_inputs,
 )
@@ -96,6 +97,14 @@ def _compute(corpus: list[dict[str, Any]]) -> tuple[list[Row], int, int]:
             result = calculate_sap_from_inputs(
                 cert_to_inputs(epc, prices=SAP_10_2_SPEC_PRICES)
             )
+            # SAP/EI rating is the UK-average rating cascade (`result`);
+            # the EPC-displayed CO2/PE use the postcode demand cascade
+            # (SAP 10.2 Appendix U p.124). Use the demand cascade for the
+            # PE/CO2-vs-cost triage so it is not confounded by the climate
+            # difference (UK-average vs local weather).
+            demand = calculate_sap_from_inputs(
+                cert_to_demand_inputs(epc, prices=SAP_10_2_SPEC_PRICES)
+            )
         except Exception:
             raised += 1
             continue
@@ -110,14 +119,14 @@ def _compute(corpus: list[dict[str, Any]]) -> tuple[list[Row], int, int]:
         rows.append(Row(
             cert=cert,
             sap_err=result.sap_score_continuous - lodged_sap,
-            co2_err_t=(result.co2_kg_per_yr / 1000.0 - lodged_co2_t)
+            co2_err_t=(demand.co2_kg_per_yr / 1000.0 - lodged_co2_t)
             if lodged_co2_t is not None else None,
-            pe_err=(result.primary_energy_kwh_per_m2 - lodged_pe)
+            pe_err=(demand.primary_energy_kwh_per_m2 - lodged_pe)
             if lodged_pe is not None else None,
             lodged_sap=lodged_sap,
             our_sap=result.sap_score_continuous,
             lodged_pe=lodged_pe,
-            our_pe=result.primary_energy_kwh_per_m2,
+            our_pe=demand.primary_energy_kwh_per_m2,
             feats=features(doc),
         ))
     return rows, skipped, raised