diff --git a/src/micropolisj/engine/Bulldozer.java b/src/micropolisj/engine/Bulldozer.java
index be97228..b8ea990 100644
--- a/src/micropolisj/engine/Bulldozer.java
+++ b/src/micropolisj/engine/Bulldozer.java
@@ -46,25 +46,27 @@ class Bulldozer extends ToolStroke
 		// zone center bit is set
 		assert isZoneCenter(currTile);
 
+		CityDimension dim = getZoneSizeFor(currTile);
+		assert dim != null;
+		assert dim.width >= 3;
+		assert dim.height >= 3;
+
 		eff.spend(1);
-		switch (getZoneSizeFor(currTile))
-		{
-		case 3:
+
+		// make explosion sound;
+		// bigger zones => bigger explosions
+
+		if (dim.width * dim.height < 16) {
 			eff.makeSound(0, 0, Sound.EXPLOSION_HIGH);
-			putRubble(new TranslatedToolEffect(eff, -1, -1), 3, 3);
-			break;
-		case 4:
-			eff.makeSound(0, 0, Sound.EXPLOSION_LOW);
-			putRubble(new TranslatedToolEffect(eff, -1, -1), 4, 4);
-			break;
-		case 6:
-			eff.makeSound(0, 0, Sound.EXPLOSION_BOTH);
-			putRubble(new TranslatedToolEffect(eff, -1, -1), 6, 6);
-			break;
-		default:
-			assert false;
-			break;
 		}
+		else if (dim.width * dim.height < 36) {
+			eff.makeSound(0, 0, Sound.EXPLOSION_LOW);
+		}
+		else {
+			eff.makeSound(0, 0, Sound.EXPLOSION_BOTH);
+		}
+
+		putRubble(new TranslatedToolEffect(eff, -1, -1), dim.width, dim.height);
 		return;
 	}
 
diff --git a/src/micropolisj/engine/Micropolis.java b/src/micropolisj/engine/Micropolis.java
index 992bad6..cc1d292 100644
--- a/src/micropolisj/engine/Micropolis.java
+++ b/src/micropolisj/engine/Micropolis.java
@@ -2293,14 +2293,19 @@ public class Micropolis
 	{
 		rateOGMem[ypos/8][xpos/8] -= 20;
 
-		int sz = TileConstants.getZoneSizeFor(zoneTile);
-		int zoneBase = (zoneTile&LOMASK)-1-sz;
+		assert isZoneCenter(zoneTile);
+		CityDimension dim = getZoneSizeFor(zoneTile);
+		assert dim != null;
+		assert dim.width >= 3;
+		assert dim.height >= 3;
+
+		int zoneBase = (zoneTile&LOMASK) - 1 - dim.width;
 
 		// this will take care of stopping smoke animations
-		shutdownZone(xpos, ypos, sz);
+		shutdownZone(xpos, ypos, dim);
 
-		for (int y = 0; y < sz; y++) {
-			for (int x = 0; x < sz; x++, zoneBase++) {
+		for (int y = 0; y < dim.height; y++) {
+			for (int x = 0; x < dim.width; x++, zoneBase++) {
 				int xtem = xpos - 1 + x;
 				int ytem = ypos - 1 + y;
 				if (!testBounds(xtem, ytem))
@@ -2321,10 +2326,13 @@ public class Micropolis
 	 * instead.
 	 * @see #shutdownZone
 	 */
-	void powerZone(int xpos, int ypos, int zoneSize)
+	void powerZone(int xpos, int ypos, CityDimension zoneSize)
 	{
-		for (int dx = 0; dx < zoneSize; dx++) {
-			for (int dy = 0; dy < zoneSize; dy++) {
+		assert zoneSize.width >= 3;
+		assert zoneSize.height >= 3;
+
+		for (int dx = 0; dx < zoneSize.width; dx++) {
+			for (int dy = 0; dy < zoneSize.height; dy++) {
 				int x = xpos - 1 + dx;
 				int y = ypos - 1 + dy;
 				int tile = getTile(x, y);
@@ -2344,10 +2352,13 @@ public class Micropolis
 	 * @see #powerZone
 	 * @see #killZone
 	 */
-	void shutdownZone(int xpos, int ypos, int zoneSize)
+	void shutdownZone(int xpos, int ypos, CityDimension zoneSize)
 	{
-		for (int dx = 0; dx < zoneSize; dx++) {
-			for (int dy = 0; dy < zoneSize; dy++) {
+		assert zoneSize.width >= 3;
+		assert zoneSize.height >= 3;
+
+		for (int dx = 0; dx < zoneSize.width; dx++) {
+			for (int dy = 0; dy < zoneSize.height; dy++) {
 				int x = xpos - 1 + dx;
 				int y = ypos - 1 + dy;
 				int tile = getTile(x, y);
diff --git a/src/micropolisj/engine/TileConstants.java b/src/micropolisj/engine/TileConstants.java
index 891afd2..8664bd2 100644
--- a/src/micropolisj/engine/TileConstants.java
+++ b/src/micropolisj/engine/TileConstants.java
@@ -396,30 +396,13 @@ public class TileConstants
 			x == BRWV);
 	}
 
-	public static int getZoneSizeFor(int tile)
+	public static CityDimension getZoneSizeFor(int tile)
 	{
-		int ch = tile & LOMASK;
-		if (ch >= RESBASE && ch < PORTBASE) {
-			return 3;
-		}
-		else if (ch >= PORTBASE && ch <= LASTPORT) {
-			return 4;
-		}
-		else if (ch >= AIRPORTBASE && ch < COALBASE) {
-			return 6;
-		}
-		else if (ch >= COALBASE && ch <= LASTPOWERPLANT) {
-			return 4;
-		}
-		else if (ch >= FIRESTBASE && ch < STADIUMBASE) {
-			return 3;
-		}
-		else if (ch >= STADIUMBASE && ch <= LASTZONE) {
-			return 4;
-		}
-		else {
-			return 0;
+		TileSpec spec = Tiles.get(tile & LOMASK);
+		if (spec.owner != null) {
+			spec = spec.owner;
 		}
+		return spec.getBuildingSize();
 	}
 
 	public static boolean isConstructed(int tile)