diff --git a/datatypes/epc/domain/mapper.py b/datatypes/epc/domain/mapper.py
index a2f436a6..a1ec7d68 100644
--- a/datatypes/epc/domain/mapper.py
+++ b/datatypes/epc/domain/mapper.py
@@ -779,9 +779,16 @@ class EpcPropertyDataMapper:
             open_chimneys_count=0,
             insulated_door_count=schema.insulated_door_count,
             draughtproofed_door_count=None,
+            # ADR-0028: 18.0 gives total + low-energy OUTLET counts, not an
+            # LED/CFL/incandescent split. Low-energy -> the calculator's LEL
+            # path; the remainder is incandescent (1 outlet ~= 1 bulb).
             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),