diff --git a/OpenRa.Game/Game.cs b/OpenRa.Game/Game.cs
index 6f3df053c2..dbc8176fee 100644
--- a/OpenRa.Game/Game.cs
+++ b/OpenRa.Game/Game.cs
@@ -311,6 +311,29 @@ namespace OpenRa.Game
 			return CanPlaceBuilding(building, xy, null, adjust);
 		}
 
+		public static bool IsCloseEnoughToBase(Player p, UnitInfo.BuildingInfo bi, int2 position)
+		{
+			var maxDistance = bi.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
+
+			var search = new PathSearch()
+			{
+				heuristic = loc =>
+				{
+					var b = Game.BuildingInfluence.GetBuildingAt(loc);
+					if (b != null && b.Owner == p) return 0;
+					if ((loc - position).Length > maxDistance)
+						return float.PositiveInfinity;	/* not quite right */
+					return 1;
+				},
+				checkForBlocked = false,
+				ignoreTerrain = true,
+			};
+
+			foreach (var t in Footprint.Tiles(bi, position)) search.AddInitialCell(t);
+
+			return Game.PathFinder.FindPath(search).Count != 0;
+		}
+
 		public static void BuildUnit(Player player, string name)
 		{
 			var producerTypes = Rules.TechTree.UnitBuiltAt( Rules.UnitInfo[ name ] );
diff --git a/OpenRa.Game/PathSearch.cs b/OpenRa.Game/PathSearch.cs
index ce63bde242..86d2646f81 100755
--- a/OpenRa.Game/PathSearch.cs
+++ b/OpenRa.Game/PathSearch.cs
@@ -15,6 +15,7 @@ namespace OpenRa.Game
 		public UnitMovementType umt;
 		Func<int2, bool> customBlock;
 		public bool checkForBlocked;
+		public bool ignoreTerrain;
 
 		public PathSearch()
 		{
@@ -39,22 +40,31 @@ namespace OpenRa.Game
 
 				if( cellInfo[ newHere.X, newHere.Y ].Seen )
 					continue;
-				if( passableCost[ (int)umt ][ newHere.X, newHere.Y ] == float.PositiveInfinity )
-					continue;
-				if( !Game.BuildingInfluence.CanMoveHere( newHere ) )
-					continue;
+				if (ignoreTerrain)
+				{
+					if (!Game.map.IsInMap(newHere.X, newHere.Y)) continue;
+				}
+				else
+				{
+					if (passableCost[(int)umt][newHere.X, newHere.Y] == float.PositiveInfinity)
+						continue;
+					if (!Game.BuildingInfluence.CanMoveHere(newHere))
+						continue;
+					if (Game.map.IsOverlaySolid(newHere))
+						continue;
+				}
 				if( checkForBlocked && Game.UnitInfluence.GetUnitAt( newHere ) != null )
 					continue;
 				if (customBlock != null && customBlock(newHere))
 					continue;
-				if (Game.map.IsOverlaySolid(newHere))
-					continue;
+				
 
 				var est = heuristic( newHere );
 				if( est == float.PositiveInfinity )
 					continue;
 
-				float cellCost = ( ( d.X * d.Y != 0 ) ? 1.414213563f : 1.0f ) * passableCost[ (int)umt ][ newHere.X, newHere.Y ];
+				float cellCost = ( ( d.X * d.Y != 0 ) ? 1.414213563f : 1.0f ) * 
+					(ignoreTerrain ? 1 : passableCost[ (int)umt ][ newHere.X, newHere.Y ]);
 				float newCost = cellInfo[ p.Location.X, p.Location.Y ].MinCost + cellCost;
 
 				if( newCost >= cellInfo[ newHere.X, newHere.Y ].MinCost )
diff --git a/OpenRa.Game/PlaceBuilding.cs b/OpenRa.Game/PlaceBuilding.cs
index ff9803ac3e..5b49e337fe 100644
--- a/OpenRa.Game/PlaceBuilding.cs
+++ b/OpenRa.Game/PlaceBuilding.cs
@@ -24,11 +24,9 @@ namespace OpenRa.Game
 				if( !Game.CanPlaceBuilding( Building, xy, true ) )
 					yield break;
 
-				var maxDistance = Building.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
-				if( !Footprint.Tiles( Building, xy ).Any(
-					t => Game.GetDistanceToBase( t, Owner ) < maxDistance ) )
+				if (!Game.IsCloseEnoughToBase(Owner, Building, xy))
 					yield break;
-
+				
 				yield return OpenRa.Game.Order.PlaceBuilding( Owner, xy, Building.Name );
 			}
 			else // rmb
diff --git a/OpenRa.Game/UiOverlay.cs b/OpenRa.Game/UiOverlay.cs
index 8c93e44060..e8a80c2375 100644
--- a/OpenRa.Game/UiOverlay.cs
+++ b/OpenRa.Game/UiOverlay.cs
@@ -46,22 +46,10 @@ namespace OpenRa.Game
 		public void DrawBuildingGrid( UnitInfo.BuildingInfo bi )
 		{
 			var position = Game.controller.MousePosition.ToInt2();
-
-			var maxDistance = bi.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
-
-			//if( ShowBuildDebug )
-			//    for( var j = 0 ; j < 128 ; j++ )
-			//        for( var i = 0 ; i < 128 ; i++ )
-			//            if( Game.GetDistanceToBase( new int2( i, j ), Game.LocalPlayer ) < maxDistance )
-			//                if( Game.IsCellBuildable( new int2( i, j ), bi.WaterBound ? UnitMovementType.Float : UnitMovementType.Wheel ) )
-			//                    if( !Game.map.ContainsResource( new int2( i, j ) ) )
-			//                        spriteRenderer.DrawSprite( unitDebug, Game.CellSize * new float2( i, j ), 0 );
-
-			var tooFarFromBase = !Footprint.Tiles( bi, position ).Any(
-				t => Game.GetDistanceToBase( t, Game.LocalPlayer ) < maxDistance );
-
+			var isCloseEnough = Game.IsCloseEnoughToBase(Game.LocalPlayer, bi, position);
+			
 			foreach( var t in Footprint.Tiles( bi, position ) )
-				spriteRenderer.DrawSprite( ( !tooFarFromBase && Game.IsCellBuildable( t, bi.WaterBound
+				spriteRenderer.DrawSprite( ( isCloseEnough && Game.IsCellBuildable( t, bi.WaterBound
 					? UnitMovementType.Float : UnitMovementType.Wheel ) && !Game.map.ContainsResource( t ) )
 					? buildOk : buildBlocked, Game.CellSize * t, 0 );