diff --git a/backend/ecmk_fetcher/xml_processor.py b/backend/ecmk_fetcher/xml_processor.py
index 38086fe8..8c9d0d1e 100644
--- a/backend/ecmk_fetcher/xml_processor.py
+++ b/backend/ecmk_fetcher/xml_processor.py
@@ -172,5 +172,33 @@ def parse_rdsap(xml_string: str) -> SapPropertyDetails:
     return result
 
 
+def _normalise_identifier(identifier: str) -> str:
+    return identifier.lower().replace(" ", "_").replace("-", "_")
+
+
 def flatten_sap_property(details: SapPropertyDetails) -> dict[str, Any]:
-    raise NotImplementedError
+    row: dict[str, Any] = {}
+
+    row["address"] = details["address"]
+    row["property_type"] = details["property_type"]
+
+    for bp in details["building_parts"]:
+        prefix = _normalise_identifier(bp["identifier"])
+
+        for i, floor in enumerate(bp["floors"], start=1):
+            floor_prefix = f"{prefix}_floor_{i}"
+            row[f"{floor_prefix}_area_m2"] = floor["area_m2"]
+            row[f"{floor_prefix}_height_m"] = floor["height_m"]
+            row[f"{floor_prefix}_heat_loss_perimeter_m"] = floor["heat_loss_perimeter_m"]
+            row[f"{floor_prefix}_party_wall_length_m"] = floor["party_wall_length_m"]
+
+        roof = bp.get("roof")
+        if roof:
+            if "construction" in roof:
+                row[f"{prefix}_roof_construction"] = roof["construction"]
+            if "insulation_location" in roof:
+                row[f"{prefix}_roof_insulation_location"] = roof["insulation_location"]
+            if "insulation_thickness_mm" in roof:
+                row[f"{prefix}_roof_insulation_thickness_mm"] = roof["insulation_thickness_mm"]
+
+    return row