diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -351,7 +351,7 @@ void DrawNewHouseTile(TileInfo *ti, Hous
 	const SpriteGroup *group;
 	ResolverObject object;
 
-	if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, ti->tileh);
+	if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);
 
 	NewHouseResolver(&object, house_id, ti->tile, GetTownByTile(ti->tile));