diff --git a/etl/load_uprns.py b/etl/load_uprns.py
old mode 100644
new mode 100755
index 2e47d792..3552efcb
--- a/etl/load_uprns.py
+++ b/etl/load_uprns.py
@@ -1,130 +1,78 @@
+#!/usr/bin/env python
 """Load buildings from CSV to Postgres
 
-
-  - create 'building' record with {
-        geometry_id: <polygon-guid>,
-        all_uprns: [<uprn>, ...],
-        uprn: <min_uprn>
-    }
+- update 'building' record with {
+    all_uprns: [<uprn>, ...],
+    uprn: <min_uprn>
+}
 """
 import csv
+import glob
 import json
 import os
 import sys
 
+from multiprocessing import Pool
+
 import psycopg2
 
 
-def main(source_file, config_path):
-    """Load config, read files and save features to the database
+def main(addressbase_dir):
+    """Read files and save features to the database
     """
-    conf = read_config(config_path)
-    dbconf = conf['database']
-    conn = psycopg2.connect(**dbconf)
+    ab_paths = list(glob.glob(os.path.join(addressbase_dir, "*.gml.csv.filtered")))
 
+    # parallel map over tiles
+    with Pool() as p:
+        p.map(load_file, ab_paths)
+
+
+def load_file(source_file):
+    """Load UPRN data from CSVs
+    """
+    config = {
+        'host': os.environ['PGHOST'],
+        'port': os.environ['PGPORT'],
+        'dbname': os.environ['PGDATABASE'],
+        'user': os.environ['PGUSER'],
+        'password': os.environ['PGPASSWORD'],
+    }
+    conn = psycopg2.connect(**config)
     with conn.cursor() as cur:
         with open(source_file, 'r') as source_fh:
             reader = csv.reader(source_fh)
             next(reader)
-            for uprn, _, _, lat, lng in reader:
-                geometry_id = find_geom(cur, float(lat), float(lng))
-                if geometry_id is not None:
-                    save_building(cur, int(uprn), geometry_id)
-                else:
-                    print("No geometry for", uprn)
+            for toid, uprn, wkt, uprn_relations in reader:
+                save_building(cur, int(uprn), toid, json.loads(uprn_relations))
         conn.commit()
     conn.close()
 
 
-def find_geom(cur, lat, lng):
-    """Find a building geometry
-    """
-    cur.execute(
-        """SELECT geometry_id FROM geometries
-        WHERE
-        ST_Within(
-            ST_Transform(
-                ST_SetSRID(ST_Point(%s, %s), 4326),
-                3857
-            ),
-            geometry_geom
-        )
-        """, (
-            lng,
-            lat
-        )
-    )
-    result = cur.fetchone()
-    if result is not None:
-        id_, = result
-        return id_
-    else:
-        return result
-
-
-def save_building(cur, uprn, geometry_id):
+def save_building(cur, uprn, toid, uprn_relations):
     """Save a building
     """
     cur.execute(
-        """SELECT building_id FROM buildings
-        WHERE
-        geometry_id = %s
+        """UPDATE buildings
+        SET uprn = %s, building_doc = %s::jsonb
+        WHERE geometry_id = (
+            SELECT geometry_id FROM geometries
+            WHERE
+            source_id = %s
+        )
         """, (
-            geometry_id,
+            uprn,
+            json.dumps({
+                'uprn_relations': uprn_relations
+            }),
+            toid
         )
     )
-    building = cur.fetchone()
-    if building is None:
-        cur.execute(
-            """INSERT INTO buildings
-            (
-                building_doc,
-                geometry_id
-            )
-            VALUES
-            (
-                %s::jsonb,
-                %s
-            )
-            """, (
-                json.dumps({
-                    'uprns': [uprn]
-                }),
-                geometry_id
-            )
-        )
-    else:
-        building_id = building[0]
-        cur.execute(
-            """UPDATE buildings
-            SET
-            building_doc = jsonb_insert(
-                building_doc,
-                '{uprns, -1}',  -- insert at end of 'uprns' array
-                '%s'::jsonb,
-                true            -- insert after location
-            )
-            WHERE
-            building_id = %s
-            """, (
-                uprn,
-                building_id
-            )
-        )
-
-
-def read_config(config_path):
-    """Read a JSON config file containing database connection details
-    """
-    with open(config_path, 'r') as fh:
-        conf = json.load(fh)
-    return conf
 
 
 if __name__ == '__main__':
     if len(sys.argv) != 2:
-        print("Usage: {} ./path/to/source/file.csv".format(
+        print("Usage: {} ./path/to/addressbase_dir/".format(
             os.path.basename(__file__)
         ))
         exit()
-    main(sys.argv[1], sys.argv[2])
+    main(sys.argv[1])