Map 20.0.0 lighting, ventilation and hot-water demand fields 🟩

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

datatypes/epc/domain/mapper.py

@@ -1077,6 +1077,8 @@ class EpcPropertyDataMapper:
     @staticmethod
     def from_rdsap_schema_20_0_0(schema: RdSapSchema20_0_0) -> EpcPropertyData:
         es = schema.sap_energy_source
+        # ADR-0027: instantaneous_wwhrs holds bath/shower ROOM counts.
+        iw = schema.sap_heating.instantaneous_wwhrs
         return EpcPropertyData(
             uprn=schema.uprn,
             assessment_type=schema.assessment_type,
@@ -1110,12 +1112,27 @@ class EpcPropertyDataMapper:
             heated_rooms_count=schema.heated_room_count,
             wet_rooms_count=0,
             extensions_count=schema.extensions_count,
-            open_chimneys_count=0,
+            open_chimneys_count=schema.open_fireplaces_count,
             insulated_door_count=schema.insulated_door_count,
             draughtproofed_door_count=None,
+            percent_draughtproofed=schema.percent_draughtproofed,
+            # ADR-0027: 20.0.0 has no flue/fan/vent counts (calculator defaults
+            # them via RdSAP Table 5), but sheltered_sides must come from
+            # built_form — else the calculator assumes mid-terrace (2) for all.
+            sap_ventilation=SapVentilation(
+                sheltered_sides=_api_sheltered_sides(schema.built_form),
+            ),
+            # ADR-0027: 20.0.0 gives total + low-energy OUTLET counts, not an
+            # LED/CFL/incandescent split. Low-energy → the calculator's LEL
+            # path (unknown LED/CFL split); the remainder is incandescent (1
+            # outlet ≈ 1 bulb). Fixes a 439-cert lighting understatement.
             led_fixed_lighting_bulbs_count=0,
             cfl_fixed_lighting_bulbs_count=0,
-            incandescent_fixed_lighting_bulbs_count=0,
+            incandescent_fixed_lighting_bulbs_count=(
+                schema.fixed_lighting_outlets_count
+                - schema.low_energy_fixed_lighting_outlets_count
+            ),
+            low_energy_fixed_lighting_bulbs_count=schema.low_energy_fixed_lighting_outlets_count,
             roofs=EpcPropertyDataMapper._map_energy_elements(schema.roofs),
             walls=EpcPropertyDataMapper._map_energy_elements(schema.walls),
             floors=EpcPropertyDataMapper._map_energy_elements(schema.floors),
@@ -1131,6 +1148,20 @@ class EpcPropertyDataMapper:
             sap_heating=SapHeating(
                 # 20.0.0 uses room counts not product index numbers; domain fields default to None
                 instantaneous_wwhrs=InstantaneousWwhrs(),
+                # ADR-0027: derive HW demand counts from the bath/shower ROOM
+                # counts (instantaneous_wwhrs is the false-friend container).
+                number_baths=(
+                    iw.rooms_with_bath_and_or_shower
+                    + iw.rooms_with_bath_and_mixer_shower
+                    if iw is not None
+                    else None
+                ),
+                mixer_shower_count=(
+                    iw.rooms_with_mixer_shower_no_bath
+                    + iw.rooms_with_bath_and_mixer_shower
+                    if iw is not None
+                    else None
+                ),
                 main_heating_details=[
                     MainHeatingDetail(
                         has_fghrs=d.has_fghrs == "Y",

datatypes/epc/domain/tests/test_from_rdsap_schema.py

@@ -1261,3 +1261,107 @@ class TestRdSap20_0_0ReducedFieldSynthesis:
 
         # Assert — cascade remaps 1 ("DG pre-2002") -> 2 (double), not raw 1.
         assert all(w.glazing_type == 2 for w in result.sap_windows)
+
+    def test_lighting_counts_incandescent_remainder_and_low_energy_as_lel(
+        self,
+    ) -> None:
+        # Arrange — ADR-0027: 20.0.0 gives total + low-energy OUTLET counts, not
+        # an LED/CFL/incandescent split. The non-low-energy remainder is
+        # incandescent (else lighting energy is understated for the 439/1000
+        # certs that have any); low-energy → the calculator's LEL path (unknown
+        # LED/CFL split). A cert with some incandescent outlets.
+        corpus = _load_20_0_0_corpus()
+        if not corpus:
+            pytest.skip("no RdSAP-Schema-20.0.0 corpus harvested")
+        cert = next(
+            (
+                c
+                for c in corpus
+                if not c.get("sap_windows")
+                and (c.get("fixed_lighting_outlets_count") or 0)
+                > (c.get("low_energy_fixed_lighting_outlets_count") or 0)
+            ),
+            None,
+        )
+        if cert is None:
+            pytest.skip("no corpus cert with incandescent lighting")
+        total = cert["fixed_lighting_outlets_count"]
+        low = cert["low_energy_fixed_lighting_outlets_count"]
+
+        # Act
+        result = EpcPropertyDataMapper.from_api_response(cert)
+
+        # Assert
+        assert result.incandescent_fixed_lighting_bulbs_count == total - low
+        assert result.low_energy_fixed_lighting_bulbs_count == low
+        assert result.led_fixed_lighting_bulbs_count == 0
+        assert result.cfl_fixed_lighting_bulbs_count == 0
+
+    def test_ventilation_maps_chimneys_draughtproofing_and_sheltered_sides(
+        self,
+    ) -> None:
+        # Arrange — ADR-0027: 20.0.0 lodges open_fireplaces_count (currently
+        # dropped → -80 m³/h/chimney for 53 certs), percent_draughtproofed, and
+        # built_form. Build sap_ventilation with sheltered_sides from built_form
+        # (else the calculator defaults every dwelling to mid-terrace=2). A cert
+        # with an open fireplace.
+        from datatypes.epc.domain.mapper import _api_sheltered_sides  # pyright: ignore[reportPrivateUsage]
+
+        corpus = _load_20_0_0_corpus()
+        if not corpus:
+            pytest.skip("no RdSAP-Schema-20.0.0 corpus harvested")
+        cert = next(
+            (
+                c
+                for c in corpus
+                if not c.get("sap_windows") and (c.get("open_fireplaces_count") or 0) >= 1
+            ),
+            None,
+        )
+        if cert is None:
+            pytest.skip("no corpus cert with an open fireplace")
+
+        # Act
+        result = EpcPropertyDataMapper.from_api_response(cert)
+
+        # Assert
+        assert result.open_chimneys_count == cert["open_fireplaces_count"]
+        assert result.percent_draughtproofed == cert["percent_draughtproofed"]
+        assert result.sap_ventilation is not None
+        assert result.sap_ventilation.sheltered_sides == _api_sheltered_sides(
+            cert["built_form"]
+        )
+
+    def test_hot_water_derives_bath_and_mixer_counts_from_room_counts(self) -> None:
+        # Arrange — ADR-0027: 20.0.0's instantaneous_wwhrs carries bath/shower
+        # ROOM counts (a false-friend for the WWHR device index). Derive
+        # number_baths and mixer_shower_count from them so HW demand isn't pinned
+        # to the calculator's modal 1-bath default (496/1000 have ≠1 bath).
+        corpus = _load_20_0_0_corpus()
+        if not corpus:
+            pytest.skip("no RdSAP-Schema-20.0.0 corpus harvested")
+        cert = next(
+            (
+                c
+                for c in corpus
+                if not c.get("sap_windows")
+                and c.get("sap_heating", {}).get("instantaneous_wwhrs")
+            ),
+            None,
+        )
+        if cert is None:
+            pytest.skip("no corpus cert with instantaneous_wwhrs")
+        iw = cert["sap_heating"]["instantaneous_wwhrs"]
+        expected_baths = iw["rooms_with_bath_and_or_shower"] + iw[
+            "rooms_with_bath_and_mixer_shower"
+        ]
+        expected_mixers = iw["rooms_with_mixer_shower_no_bath"] + iw[
+            "rooms_with_bath_and_mixer_shower"
+        ]
+
+        # Act
+        result = EpcPropertyDataMapper.from_api_response(cert)
+
+        # Assert
+        assert result.sap_heating.number_baths == expected_baths
+        assert result.sap_heating.mixer_shower_count == expected_mixers