diff --git a/constrain/library/AppendixGHVACSystemFanOperation.py b/constrain/library/AppendixGHVACSystemFanOperation.py
index f7ce92f0..76f9388a 100644
--- a/constrain/library/AppendixGHVACSystemFanOperation.py
+++ b/constrain/library/AppendixGHVACSystemFanOperation.py
@@ -57,6 +57,7 @@
 - tol_o: occupancy threshold; below that value the zones are considered unoccupied.
 
 """
+
 from constrain.checklib import RuleCheckBase
 
 
diff --git a/constrain/library/ExteriorLightingControlDaylightOff.py b/constrain/library/ExteriorLightingControlDaylightOff.py
index 76f25e02..596b4aaa 100644
--- a/constrain/library/ExteriorLightingControlDaylightOff.py
+++ b/constrain/library/ExteriorLightingControlDaylightOff.py
@@ -34,6 +34,7 @@
 - total_lighting_power: reported total lighting power (not the design total lighting power)
 
 """
+
 from constrain.checklib import RuleCheckBase
 import numpy as np
 
diff --git a/constrain/library/ExteriorLightingControlOccupancySensingReduction.py b/constrain/library/ExteriorLightingControlOccupancySensingReduction.py
index 81c7811a..3a0f4d84 100644
--- a/constrain/library/ExteriorLightingControlOccupancySensingReduction.py
+++ b/constrain/library/ExteriorLightingControlOccupancySensingReduction.py
@@ -33,6 +33,7 @@
 - tol_o: occupancy threshold; below that value the zones are considered unoccupied.
 
 """
+
 from constrain.checklib import RuleCheckBase
 import numpy as np
 
diff --git a/constrain/library/InteriorLightingControlAutomaticFullOff.py b/constrain/library/InteriorLightingControlAutomaticFullOff.py
index 79092395..3ac1e8c3 100644
--- a/constrain/library/InteriorLightingControlAutomaticFullOff.py
+++ b/constrain/library/InteriorLightingControlAutomaticFullOff.py
@@ -41,6 +41,7 @@
 - tol_o: occupancy threshold; below that value the zones are considered unoccupied.
 
 """
+
 from constrain.checklib import RuleCheckBase
 import numpy as np
 
diff --git a/constrain/library/MZSystemOccupiedStandbyVentilationZoneControl.py b/constrain/library/MZSystemOccupiedStandbyVentilationZoneControl.py
index 13ee7bb2..df35213e 100644
--- a/constrain/library/MZSystemOccupiedStandbyVentilationZoneControl.py
+++ b/constrain/library/MZSystemOccupiedStandbyVentilationZoneControl.py
@@ -33,6 +33,7 @@
 - m_oa_zone_requirement: required zone outdoor air flow rate for the reported period
 
 """
+
 from constrain.checklib import RuleCheckBase
 import numpy as np