diff --git a/domain/sap10_calculator/rdsap/cert_to_inputs.py b/domain/sap10_calculator/rdsap/cert_to_inputs.py
index 0ae21a4fe..283b9f8c6 100644
--- a/domain/sap10_calculator/rdsap/cert_to_inputs.py
+++ b/domain/sap10_calculator/rdsap/cert_to_inputs.py
@@ -8595,16 +8595,16 @@ def cert_to_inputs(
             immersion_high_rate_fraction=_hw_immersion_high_frac,
         )
         _hw_extra_standing = 0.0
-    _heat_network_standing = _heat_network_standing_charge_gbp(epc, main)
     standing_charges_total = (
-        _heat_network_standing
-        if _heat_network_standing is not None
-        else additional_standing_charges_gbp(
+        _standing_charges_total_gbp(
+            epc,
+            main,
             main_fuel_code=_main_fuel_code(main),
             water_heating_fuel_code=_water_heating_fuel_code(epc),
             tariff=_rdsap_tariff(epc),
         )
-    ) + _hw_extra_standing
+        + _hw_extra_standing
+    )
 
     # SAP 10.2 Appendix C §C3.2 (PDF p.51) — heat-network distribution
     # pumping electricity (worksheet (313)/(372)/(472)). None for