diff --git a/OpenRA.Game/OpenRA.Game.csproj b/OpenRA.Game/OpenRA.Game.csproj
index d41cd7a7c4..5c6de4ce1a 100644
--- a/OpenRA.Game/OpenRA.Game.csproj
+++ b/OpenRA.Game/OpenRA.Game.csproj
@@ -159,7 +159,6 @@
     <Compile Include="Traits\Util.cs" />
     <Compile Include="Traits\ValidateOrder.cs" />
     <Compile Include="Traits\World\Country.cs" />
-    <Compile Include="Traits\World\ResourceLayer.cs" />
     <Compile Include="Traits\World\ResourceType.cs" />
     <Compile Include="Traits\World\ScreenShaker.cs" />
     <Compile Include="Traits\World\Shroud.cs" />
diff --git a/OpenRA.Game/Traits/World/ResourceType.cs b/OpenRA.Game/Traits/World/ResourceType.cs
index 6bdbb4f582..c6927a97a4 100644
--- a/OpenRA.Game/Traits/World/ResourceType.cs
+++ b/OpenRA.Game/Traits/World/ResourceType.cs
@@ -28,6 +28,7 @@ namespace OpenRA.Traits
 
 		public readonly string[] AllowedTerrainTypes = { };
 		public readonly bool AllowUnderActors = false;
+		public readonly bool AllowUnderBuildings = false;
 
 		public PipType PipColor = PipType.Yellow;
 
diff --git a/OpenRA.Mods.Cnc/PoisonedByTiberium.cs b/OpenRA.Mods.Cnc/PoisonedByTiberium.cs
index d2287918be..8c8c13aa1c 100644
--- a/OpenRA.Mods.Cnc/PoisonedByTiberium.cs
+++ b/OpenRA.Mods.Cnc/PoisonedByTiberium.cs
@@ -10,6 +10,7 @@
 
 using System.Linq;
 using OpenRA.Traits;
+using OpenRA.Mods.RA;
 
 namespace OpenRA.Mods.Cnc
 {
diff --git a/OpenRA.Mods.D2k/D2kResourceLayer.cs b/OpenRA.Mods.D2k/D2kResourceLayer.cs
index 7438e1948a..5484ef9008 100644
--- a/OpenRA.Mods.D2k/D2kResourceLayer.cs
+++ b/OpenRA.Mods.D2k/D2kResourceLayer.cs
@@ -11,8 +11,10 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using OpenRA.Mods.RA;
+using OpenRA.Traits;
 
-namespace OpenRA.Traits
+namespace OpenRA.Mods.D2k
 {
 	public class D2kResourceLayerInfo : TraitInfo<D2kResourceLayer> { }
 
diff --git a/OpenRA.Mods.RA/Buildings/FootprintUtils.cs b/OpenRA.Mods.RA/Buildings/FootprintUtils.cs
index 0d288dfd97..95a595bfe1 100644
--- a/OpenRA.Mods.RA/Buildings/FootprintUtils.cs
+++ b/OpenRA.Mods.RA/Buildings/FootprintUtils.cs
@@ -23,13 +23,13 @@ namespace OpenRA.Mods.RA.Buildings
 			var footprint = buildingInfo.Footprint.Where(x => !char.IsWhiteSpace(x));
 
 			var buildingTraits = rules.Actors[name].Traits;
-			if (buildingTraits.Contains<BibInfo>() && !(buildingTraits.Get<BibInfo>().HasMinibib))
+			if (buildingTraits.Contains<BibInfo>() && !buildingTraits.Get<BibInfo>().HasMinibib)
 			{
 				dim += new CVec(0, 1);
 				footprint = footprint.Concat(new char[dim.X]);
 			}
 
-			return TilesWhere( name, dim, footprint.ToArray(), a => a != '_' ).Select( t => t + topLeft );
+			return TilesWhere(name, dim, footprint.ToArray(), a => a != '_').Select(t => t + topLeft);
 		}
 
 		public static IEnumerable<CPos> Tiles(Actor a)
@@ -39,20 +39,20 @@ namespace OpenRA.Mods.RA.Buildings
 
 		public static IEnumerable<CPos> UnpathableTiles(string name, BuildingInfo buildingInfo, CPos position)
 		{
-			var footprint = buildingInfo.Footprint.Where( x => !char.IsWhiteSpace( x ) ).ToArray();
-			foreach( var tile in TilesWhere( name, (CVec)buildingInfo.Dimensions, footprint, a => a == 'x' ) )
+			var footprint = buildingInfo.Footprint.Where(x => !char.IsWhiteSpace(x)).ToArray();
+			foreach (var tile in TilesWhere(name, (CVec)buildingInfo.Dimensions, footprint, a => a == 'x'))
 				yield return tile + position;
 		}
 
 		static IEnumerable<CVec> TilesWhere(string name, CVec dim, char[] footprint, Func<char, bool> cond)
 		{
-			if( footprint.Length != dim.X * dim.Y )
-				throw new InvalidOperationException( "Invalid footprint for " + name );
+			if (footprint.Length != dim.X * dim.Y)
+				throw new InvalidOperationException("Invalid footprint for " + name);
 			var index = 0;
 
-			for( var y = 0 ; y < dim.Y ; y++ )
-				for( var x = 0 ; x < dim.X ; x++ )
-					if( cond( footprint[ index++ ] ) )
+			for (var y = 0; y < dim.Y; y++)
+				for (var x = 0; x < dim.X; x++)
+					if (cond(footprint[index++]))
 						yield return new CVec(x, y);
 		}
 
diff --git a/OpenRA.Mods.RA/Crate.cs b/OpenRA.Mods.RA/Crate.cs
index e95b277c30..df94f6de89 100644
--- a/OpenRA.Mods.RA/Crate.cs
+++ b/OpenRA.Mods.RA/Crate.cs
@@ -96,7 +96,8 @@ namespace OpenRA.Mods.RA
 			if (!info.TerrainTypes.Contains(type))
 				return false;
 
-			if (self.World.WorldActor.Trait<BuildingInfluence>().GetBuildingAt(cell) != null) return false;
+			if (self.World.WorldActor.Trait<BuildingInfluence>().GetBuildingAt(cell) != null)
+				return false;
 
 			if (!checkTransientActors)
 				return true;
diff --git a/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj b/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
index d60a95b5ce..19a2a6bd9d 100644
--- a/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
+++ b/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
@@ -520,6 +520,7 @@
     <Compile Include="Player\ProvidesCustomPrerequisite.cs" />
     <Compile Include="Lint\CheckActors.cs" />
     <Compile Include="Lint\CheckMapCordon.cs" />
+    <Compile Include="World\ResourceLayer.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRA.Game\OpenRA.Game.csproj">
diff --git a/OpenRA.Game/Traits/World/ResourceLayer.cs b/OpenRA.Mods.RA/World/ResourceLayer.cs
similarity index 93%
rename from OpenRA.Game/Traits/World/ResourceLayer.cs
rename to OpenRA.Mods.RA/World/ResourceLayer.cs
index 357c11339a..02eac34b10 100644
--- a/OpenRA.Game/Traits/World/ResourceLayer.cs
+++ b/OpenRA.Mods.RA/World/ResourceLayer.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -12,9 +12,12 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
+using OpenRA.Mods.RA.Buildings;
+using OpenRA.Traits;
 
-namespace OpenRA.Traits
+namespace OpenRA.Mods.RA
 {
+	[Desc("Attach this to the world actor.")]
 	public class ResourceLayerInfo : TraitInfo<ResourceLayer>, Requires<ResourceTypeInfo> { }
 
 	public class ResourceLayer : IRenderOverlay, IWorldLoaded, ITickRender
@@ -22,6 +25,9 @@ namespace OpenRA.Traits
 		static readonly CellContents EmptyCell = new CellContents();
 
 		World world;
+
+		BuildingInfluence buildingInfluence;
+
 		protected CellLayer<CellContents> content;
 		protected CellLayer<CellContents> render;
 		List<CPos> dirty;
@@ -54,6 +60,9 @@ namespace OpenRA.Traits
 		public void WorldLoaded(World w, WorldRenderer wr)
 		{
 			this.world = w;
+
+			buildingInfluence = world.WorldActor.Trait<BuildingInfluence>();
+
 			content = new CellLayer<CellContents>(w.Map);
 			render = new CellLayer<CellContents>(w.Map);
 			dirty = new List<CPos>();
@@ -139,6 +148,9 @@ namespace OpenRA.Traits
 			if (!rt.Info.AllowUnderActors && world.ActorMap.AnyUnitsAt(cell))
 				return false;
 
+			if (!rt.Info.AllowUnderBuildings && buildingInfluence.GetBuildingAt(cell) != null)
+				return false;
+
 			return true;
 		}
 
diff --git a/mods/ts/mod.yaml b/mods/ts/mod.yaml
index 6b9e1eb993..6321b0a615 100644
--- a/mods/ts/mod.yaml
+++ b/mods/ts/mod.yaml
@@ -90,8 +90,8 @@ Chrome:
 	mods/ts/chrome.yaml
 
 Assemblies:
-	mods/d2k/OpenRA.Mods.D2k.dll
 	mods/ra/OpenRA.Mods.RA.dll
+	mods/d2k/OpenRA.Mods.D2k.dll
 	mods/cnc/OpenRA.Mods.Cnc.dll
 	mods/ts/OpenRA.Mods.TS.dll