diff --git a/src/openrct2/world/banner.cpp b/src/openrct2/world/banner.cpp
index 2033fac8bd..acb576f075 100644
--- a/src/openrct2/world/banner.cpp
+++ b/src/openrct2/world/banner.cpp
@@ -79,7 +79,7 @@ static money32 BannerRemove(sint16 x, sint16 y, uint8 baseHeight, uint8 directio
         return MONEY32_UNDEFINED;
     }
 
-    if (!(gScreenFlags & SCREEN_FLAGS_SCENARIO_EDITOR) && !gCheatsSandboxMode && !map_is_location_owned(x, y, z - 16))
+    if (!map_can_build_at(x, y, z - 16))
     {
         return MONEY32_UNDEFINED;
     }
@@ -131,13 +131,11 @@ static money32 BannerSetColour(sint16 x, sint16 y, uint8 baseHeight, uint8 direc
     gCommandPosition.y = y + 16;
     gCommandPosition.z = z;
 
-    if (!(gScreenFlags & SCREEN_FLAGS_SCENARIO_EDITOR) && !gCheatsSandboxMode)
+    if (!map_can_build_at(x, y, z - 16))
     {
-        if (!map_is_location_owned(x, y, z - 16))
-        {
-            return MONEY32_UNDEFINED;
-        }
+        return MONEY32_UNDEFINED;
     }
+    
 
     if (flags & GAME_COMMAND_FLAG_APPLY)
     {
@@ -190,7 +188,7 @@ static money32 BannerPlace(sint16 x, sint16 y, uint8 pathBaseHeight, uint8 direc
         return MONEY32_UNDEFINED;
     }
 
-    if (x >= 256 * 32 || y >= 256 * 32)
+    if (!map_is_location_valid(x, y))
     {
         return MONEY32_UNDEFINED;
     }
@@ -219,9 +217,7 @@ static money32 BannerPlace(sint16 x, sint16 y, uint8 pathBaseHeight, uint8 direc
         return MONEY32_UNDEFINED;
     }
 
-    if (!(gScreenFlags & SCREEN_FLAGS_SCENARIO_EDITOR) &&
-        !gCheatsSandboxMode &&
-        !map_is_location_owned(x, y, pathBaseHeight * 16))
+    if (!map_can_build_at(x, y, pathBaseHeight * 16))
     {
         return MONEY32_UNDEFINED;
     }
diff --git a/src/openrct2/world/map.c b/src/openrct2/world/map.c
index 44fcc1eaa5..391f8aede6 100644
--- a/src/openrct2/world/map.c
+++ b/src/openrct2/world/map.c
@@ -788,6 +788,17 @@ bool map_is_location_valid(sint32 x, sint32 y)
 	return false;
 }
 
+bool map_can_build_at(sint32 x, sint32 y, sint32 z)
+{
+	if (gScreenFlags & SCREEN_FLAGS_SCENARIO_EDITOR)
+		return true;
+	if (gCheatsSandboxMode)
+		return true;
+	if (map_is_location_owned(x, y, z))
+		return true;
+	return false;
+}
+
 /**
  *
  *  rct2: 0x00664F72
diff --git a/src/openrct2/world/map.h b/src/openrct2/world/map.h
index ca88007207..ad8833559d 100644
--- a/src/openrct2/world/map.h
+++ b/src/openrct2/world/map.h
@@ -436,6 +436,7 @@ void map_remove_provisional_elements();
 void map_restore_provisional_elements();
 void map_update_path_wide_flags();
 bool map_is_location_valid(sint32 x, sint32 y);
+bool map_can_build_at(sint32 x, sint32 y, sint32 z);
 bool map_is_location_owned(sint32 x, sint32 y, sint32 z);
 bool map_is_location_in_park(sint32 x, sint32 y);
 bool map_is_location_owned_or_has_rights(sint32 x, sint32 y);