working on loft at rafters

backend/onboarders/epc_descriptions.py

@@ -364,10 +364,6 @@ RoofEfficiencyRule = Union[
 ]
 
 
-def flat_limited_insulation_efficiency(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
-    pass
-
-
 def flat_insulated_efficiency_age_band(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
     """
     before 1900, 1900-1929, 1930-1949, 1950-1966, 1967-1975  -> Pitched, no insulation, Very Poor
@@ -424,6 +420,19 @@ def flat_insulated_efficiency_thickness(insulation_thickness: int | None) -> Epc
     return EpcEfficiency.VERY_POOR
 
 
+def flat_efficiency(insulation_thickness: int | None, age_band: EpcConstructionAgeBand) -> EpcEfficiency:
+    """
+    Combines both age band and insulation thickness to determine flat roof efficiency.
+    :param insulation_thickness: Insulation thickness in mm
+    :param age_band: EpcConstructionAgeBand
+    :return: EpcEfficiency
+    """
+    if insulation_thickness is not None:
+        return flat_insulated_efficiency_thickness(insulation_thickness)
+
+    return flat_insulated_efficiency_age_band(age_band)
+
+
 def loft_insulated_efficiency(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
     """
     2023 onwards -> Very Good
@@ -451,39 +460,156 @@ def loft_insulated_efficiency(age_band: EpcConstructionAgeBand) -> EpcEfficiency
     return EpcEfficiency.AVERAGE
 
 
-def flat_limited_efficiency(
-    age_band: EpcConstructionAgeBand,
+def thatched_efficiency_age_band(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
+    """
+    Maps thatched roof efficiency based on construction age band.
+    :param age_band: EpcConstructionAgeBand
+    :return: EpcEfficiency
+    """
+    year = age_band.start_year()
+    if year >= 2023:
+        return EpcEfficiency.VERY_GOOD
+    if year >= 2003:
+        return EpcEfficiency.GOOD
+
+    return EpcEfficiency.AVERAGE
+
+
+def thatched_efficiency_thickness(insulation_thickness: int | None) -> EpcEfficiency:
+    """
+    Maps thatched roof efficiency based on insulation thickness.
+    :param insulation_thickness: Insulation thickness in mm
+    :return: EpcEfficiency
+    """
+    if insulation_thickness is None:
+        raise ValueError("Insulation thickness is required for thatched efficiency calculation")
+
+    if insulation_thickness >= 175:
+        return EpcEfficiency.VERY_GOOD
+
+    if insulation_thickness >= 25:
+        return EpcEfficiency.GOOD
+
+    return EpcEfficiency.AVERAGE
+
+
+def thatched_efficiency(
     insulation_thickness: int | None,
+    age_band: EpcConstructionAgeBand,
 ) -> EpcEfficiency:
     """
-    If we have an insulation thickness, 12mm results in a very poor rating. 25mm or above results in a poor rating.
-    If we don't have an insulation thickness, we fall back to age band, where
-    - 1976 - 1982 = Flat, limited insulation, poor efficiency
-    - 1967 - 1975 = Flat, limited insulation, Very Poor
-    :param age_band:
-    :param insulation_thickness:
-    :return:
+    Combines both age band and insulation thickness to determine thatched roof efficiency.
+    :param insulation_thickness: Insulation thickness in mm
+    :param age_band: EpcConstructionAgeBand
+    :return: EpcEfficiency
     """
-
     if insulation_thickness is not None:
-        if insulation_thickness >= 25:
-            return EpcEfficiency.POOR
-        return EpcEfficiency.VERY_POOR
+        return thatched_efficiency_thickness(insulation_thickness)
 
-    if age_band == EpcConstructionAgeBand.from_1976_to_1982:
+    return thatched_efficiency_age_band(age_band)
+
+
+def sloping_ceiling_efficiency_age_band(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
+    """
+    Maps sloping ceiling roof efficiency based on construction age band.
+    :param age_band: EpcConstructionAgeBand
+    :return: EpcEfficiency
+    """
+    year = age_band.start_year()
+    if year >= 2023:
+        return EpcEfficiency.VERY_GOOD
+    if year >= 2003:
+        return EpcEfficiency.GOOD
+    if year >= 1983:
+        return EpcEfficiency.AVERAGE
+    if year >= 1976:
         return EpcEfficiency.POOR
 
-    if age_band == EpcConstructionAgeBand.from_1967_to_1975:
-        return EpcEfficiency.VERY_POOR
+    return EpcEfficiency.VERY_POOR
 
-    raise ValueError("Cannot determine flat limited insulation efficiency without insulation thickness or age band")
+
+def sloping_ceiling_efficiency_thickness(insulation_thickness: int | None) -> EpcEfficiency:
+    """
+    Maps sloping ceiling roof efficiency based on insulation thickness.
+    :param insulation_thickness: Insulation thickness in mm
+    :return: EpcEfficiency
+    """
+    if insulation_thickness is None:
+        raise ValueError("Insulation thickness is required for sloping ceiling efficiency calculation")
+
+    if insulation_thickness >= 270:
+        return EpcEfficiency.VERY_GOOD
+
+    if insulation_thickness >= 150:
+        return EpcEfficiency.GOOD
+
+    if insulation_thickness >= 75:
+        return EpcEfficiency.AVERAGE
+
+    if insulation_thickness >= 25:
+        return EpcEfficiency.POOR
+
+    return EpcEfficiency.VERY_POOR
+
+
+def sloping_ceiling_efficiency(
+    insulation_thickness: int | None,
+    age_band: EpcConstructionAgeBand,
+) -> EpcEfficiency:
+    """
+    Combines both age band and insulation thickness to determine sloping ceiling roof efficiency.
+    :param insulation_thickness: Insulation thickness in mm
+    :param age_band: EpcConstructionAgeBand
+    :return: EpcEfficiency
+    """
+    if insulation_thickness is not None:
+        return sloping_ceiling_efficiency_thickness(insulation_thickness)
+
+    return sloping_ceiling_efficiency_age_band(age_band)
+
+
+def loft_insulated_at_rafters_efficiency_thickness(insulation_thickness: int | None) -> EpcEfficiency:
+    """
+    400mm, 350mm = very good
+    200-300mm = good
+    125-175 = average
+    50-100 = poor
+    25 and below= very poor
+    :return:
+    """
+    if insulation_thickness is None:
+        raise ValueError("Insulation thickness is required for loft insulated at rafters efficiency calculation")
+
+    if insulation_thickness >= 350:
+        return EpcEfficiency.VERY_GOOD
+
+    if insulation_thickness >= 200:
+        return EpcEfficiency.GOOD
+
+    if insulation_thickness >= 125:
+        return EpcEfficiency.AVERAGE
+
+    if insulation_thickness >= 50:
+        return EpcEfficiency.POOR
+
+    return EpcEfficiency.VERY_POOR
+
+
+def loft_insulated_at_rafters_efficiency_age_band(age_band: EpcConstructionAgeBand) -> EpcEfficiency:
+    """
+    # 2023 onwards -> Very Good
+    # 2012-2022 -> Good
+    Before 1900 -> Very Poor
+    :param age_band:
+    :return:
+    """
 
 
 ROOF_DESCRIPTION_EFFICIENCIES: Mapping[EpcRoofDescriptions, RoofEfficiencyRule] = {
     # Flat roof
     EpcRoofDescriptions.flat_no_insulation: EpcEfficiency.VERY_POOR,
-    EpcRoofDescriptions.flat_limited_insulation: flat_limited_insulation_efficiency,
-    EpcRoofDescriptions.flat_insulated: flat_insulated_efficiency,
+    EpcRoofDescriptions.flat_limited_insulation: flat_efficiency,
+    EpcRoofDescriptions.flat_insulated: flat_efficiency,
 
     # Loft:
     # value mappings
@@ -511,4 +637,13 @@ ROOF_DESCRIPTION_EFFICIENCIES: Mapping[EpcRoofDescriptions, RoofEfficiencyRule]
     # Another dwelling above
     EpcRoofDescriptions.another_dwelling_above: EpcEfficiency.NA,
 
+    # Thatched
+    EpcRoofDescriptions.thatched: thatched_efficiency,
+    EpcRoofDescriptions.thatched_with_additional_insulation: thatched_efficiency,
+
+    # Sloping ceiling
+    EpcRoofDescriptions.sloping_pitched_insulated: sloping_ceiling_efficiency,
+    EpcRoofDescriptions.sloping_pitched_limited_insulation: sloping_ceiling_efficiency,
+    EpcRoofDescriptions.sloping_pitched_no_insulation: EpcEfficiency.VERY_POOR,
+
 }