diff --git a/src/object_cmd.cpp b/src/object_cmd.cpp
--- a/src/object_cmd.cpp
+++ b/src/object_cmd.cpp
@@ -230,7 +230,7 @@ CommandCost CmdBuildObject(TileIndex til
 
 		/* So, now the surface is checked... check the slope of said surface. */
 		int allowed_z;
-		if (GetTilePixelSlope(tile, (uint*)&allowed_z) != SLOPE_FLAT) allowed_z += TILE_HEIGHT;
+		if (GetTileSlope(tile, (uint*)&allowed_z) != SLOPE_FLAT) allowed_z++;
 
 		TILE_AREA_LOOP(t, ta) {
 			uint16 callback = CALLBACK_FAILED;
@@ -643,7 +643,7 @@ void GenerateObjects()
 		TileIndex tile = RandomTile();
 
 		uint h;
-		if (IsTileType(tile, MP_CLEAR) && GetTilePixelSlope(tile, &h) == SLOPE_FLAT && h >= TILE_HEIGHT * 4 && !IsBridgeAbove(tile)) {
+		if (IsTileType(tile, MP_CLEAR) && GetTileSlope(tile, &h) == SLOPE_FLAT && h >= 4 && !IsBridgeAbove(tile)) {
 			TileIndex t = tile;
 			if (CircularTileSearch(&t, 9, HasTransmitter, NULL)) continue;
 
@@ -680,7 +680,7 @@ void GenerateObjects()
 
 		for (int j = 0; j < 19; j++) {
 			uint h;
-			if (IsTileType(tile, MP_CLEAR) && GetTilePixelSlope(tile, &h) == SLOPE_FLAT && h <= TILE_HEIGHT * 2 && !IsBridgeAbove(tile)) {
+			if (IsTileType(tile, MP_CLEAR) && GetTileSlope(tile, &h) == SLOPE_FLAT && h <= 2 && !IsBridgeAbove(tile)) {
 				BuildObject(OBJECT_LIGHTHOUSE, tile);
 				IncreaseGeneratingWorldProgress(GWP_OBJECT);
 				lighthouses_to_build--;
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -306,8 +306,8 @@ static StringID GenerateStationName(Stat
 	}
 
 	/* check elevation compared to town */
-	uint z = GetTilePixelZ(tile);
-	uint z2 = GetTilePixelZ(t->xy);
+	uint z = GetTileZ(tile);
+	uint z2 = GetTileZ(t->xy);
 	if (z < z2) {
 		if (HasBit(free_names, M(STR_SV_STNAME_VALLEY))) return STR_SV_STNAME_VALLEY;
 	} else if (z > z2) {
@@ -665,7 +665,7 @@ CommandCost CheckBuildableTile(TileIndex
 	if (ret.Failed()) return ret;
 
 	uint z;
-	Slope tileh = GetTilePixelSlope(tile, &z);
+	Slope tileh = GetTileSlope(tile, &z);
 
 	/* Prohibit building if
 	 *   1) The tile is "steep" (i.e. stretches two height levels).
@@ -677,7 +677,7 @@ CommandCost CheckBuildableTile(TileIndex
 	}
 
 	CommandCost cost(EXPENSES_CONSTRUCTION);
-	int flat_z = z + GetSlopeMaxPixelZ(tileh);
+	int flat_z = z + GetSlopeMaxZ(tileh);
 	if (tileh != SLOPE_FLAT) {
 		/* Forbid building if the tile faces a slope in a invalid direction. */
 		for (DiagDirection dir = DIAGDIR_BEGIN; dir != DIAGDIR_END; dir++) {
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1935,7 +1935,7 @@ static inline bool CheckBuildHouseSameZ(
 	if (!CanBuildHouseHere(tile, town, noslope)) return false;
 
 	/* if building on slopes is allowed, there will be flattening foundation (to tile max z) */
-	if (GetTileMaxPixelZ(tile) != z) return false;
+	if (GetTileMaxZ(tile) != z) return false;
 
 	return true;
 }
@@ -2139,7 +2139,7 @@ static bool BuildTownHouse(Town *t, Tile
 		houses[num++] = (HouseID)i;
 	}
 
-	uint maxz = GetTileMaxPixelZ(tile);
+	uint maxz = GetTileMaxZ(tile);
 	TileIndex baseTile = tile;
 
 	while (probability_max > 0) {