diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index 49d839cb9a..42336b5898 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -370,7 +370,6 @@
     <Compile Include="Traits\Render\RenderBuilding.cs" />
     <Compile Include="Traits\Render\RenderBuildingCharge.cs" />
     <Compile Include="Traits\Render\RenderBuildingTurreted.cs" />
-    <Compile Include="Traits\Render\RenderBuildingWarFactory.cs" />
     <Compile Include="Traits\Render\RenderEditorOnly.cs" />
     <Compile Include="Traits\Render\RenderFlare.cs" />
     <Compile Include="Traits\Render\RenderHarvester.cs" />
diff --git a/OpenRA.Mods.Common/Traits/Render/RenderBuildingWarFactory.cs b/OpenRA.Mods.Common/Traits/Render/RenderBuildingWarFactory.cs
deleted file mode 100644
index a8c53111c6..0000000000
--- a/OpenRA.Mods.Common/Traits/Render/RenderBuildingWarFactory.cs
+++ /dev/null
@@ -1,96 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2015 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,
- * see COPYING.
- */
-#endregion
-
-using System.Collections.Generic;
-using System.Linq;
-using OpenRA.Graphics;
-using OpenRA.Mods.Common.Graphics;
-using OpenRA.Traits;
-
-namespace OpenRA.Mods.Common.Traits
-{
-	class RenderBuildingWarFactoryInfo : RenderBuildingInfo
-	{
-		public override object Create(ActorInitializer init) { return new RenderBuildingWarFactory(init, this); }
-
-		public override IEnumerable<IActorPreview> RenderPreviewSprites(ActorPreviewInitializer init, RenderSpritesInfo rs, string image, int facings, PaletteReference p)
-		{
-			foreach (var orig in base.RenderPreviewSprites(init, rs, image, facings, p))
-				yield return orig;
-
-			// Show additional roof overlay
-			var anim = new Animation(init.World, image, () => 0);
-			anim.PlayRepeating("idle-top");
-
-			var bi = init.Actor.Traits.Get<BuildingInfo>();
-			var offset = FootprintUtils.CenterOffset(init.World, bi).Y + 512;
-			yield return new SpriteActorPreview(anim, WVec.Zero, offset, p, rs.Scale);
-		}
-	}
-
-	class RenderBuildingWarFactory : RenderBuilding, INotifyBuildComplete, ITick, INotifyProduction, INotifySold
-	{
-		readonly Animation roof;
-		bool isOpen;
-		CPos openExit;
-		bool buildComplete;
-
-		public RenderBuildingWarFactory(ActorInitializer init, RenderBuildingInfo info)
-			: base(init, info)
-		{
-			roof = new Animation(init.World, GetImage(init.Self));
-			var bi = init.Self.Info.Traits.Get<BuildingInfo>();
-
-			// Additional 512 units move from center -> top of cell
-			var offset = FootprintUtils.CenterOffset(init.World, bi).Y + 512;
-			Add("roof", new AnimationWithOffset(roof, null,
-				() => !buildComplete, offset));
-		}
-
-		public override void BuildingComplete(Actor self)
-		{
-			roof.Play(NormalizeSequence(self,
-				self.GetDamageState() > DamageState.Heavy ? "damaged-idle-top" : "idle-top"));
-			buildComplete = true;
-		}
-
-		public override void Tick(Actor self)
-		{
-			base.Tick(self);
-			if (isOpen && !self.World.ActorMap.GetUnitsAt(openExit).Any(a => a != self))
-			{
-				isOpen = false;
-				roof.PlayBackwardsThen(NormalizeSequence(self, "build-top"),
-					() => roof.Play(NormalizeSequence(self, "idle-top")));
-			}
-		}
-
-		public override void DamageStateChanged(Actor self, AttackInfo e)
-		{
-			if (roof.CurrentSequence != null)
-			{
-				if (e.DamageState >= DamageState.Heavy)
-					roof.ReplaceAnim("damaged-" + roof.CurrentSequence.Name);
-				else
-					roof.ReplaceAnim(roof.CurrentSequence.Name.Replace("damaged-", ""));
-			}
-
-			base.DamageStateChanged(self, e);
-		}
-
-		public void UnitProduced(Actor self, Actor other, CPos exit)
-		{
-			roof.PlayThen(NormalizeSequence(self, "build-top"), () => { isOpen = true; openExit = exit; });
-		}
-
-		public void Selling(Actor self) { Remove("roof"); }
-		public void Sold(Actor self) { }
-	}
-}
diff --git a/mods/cnc/rules/structures.yaml b/mods/cnc/rules/structures.yaml
index 70b06a605f..f27dff3aa0 100644
--- a/mods/cnc/rules/structures.yaml
+++ b/mods/cnc/rules/structures.yaml
@@ -363,8 +363,9 @@ WEAP:
 	RevealsShroud:
 		Range: 4c0
 	Bib:
-	-RenderBuilding:
-	RenderBuildingWarFactory:
+	WithProductionDoorOverlay:
+		Sequence: idle-top
+		BuildSequence: build-top
 	RallyPoint:
 		RallyPoint: 0,3
 	Exit@1:
diff --git a/mods/d2k/rules/structures.yaml b/mods/d2k/rules/structures.yaml
index 0038aec005..cfe97627c2 100644
--- a/mods/d2k/rules/structures.yaml
+++ b/mods/d2k/rules/structures.yaml
@@ -200,8 +200,7 @@ refinery:
 		DeliveryOffset: 2,2
 		DeliveringActor: carryall.reinforce
 		Facing: 160
-	-RenderBuilding:
-	RenderBuildingWarFactory:
+	RenderBuilding:
 		Image: refinery.harkonnen
 		RaceImages:
 			atreides: refinery.atreides
diff --git a/mods/ra/rules/fakes.yaml b/mods/ra/rules/fakes.yaml
index 9d39c1e6f3..c24069c28c 100644
--- a/mods/ra/rules/fakes.yaml
+++ b/mods/ra/rules/fakes.yaml
@@ -37,9 +37,10 @@ WEAF:
 		Footprint: xxx xxx
 		Dimensions: 3,2
 	Bib:
-	-RenderBuilding:
-	RenderBuildingWarFactory:
+	RenderBuilding:
 		Image: WEAP
+	WithIdleOverlay@ROOF:
+		Sequence: idle-top
 	Valued:
 		Cost: 200
 
diff --git a/mods/ra/rules/structures.yaml b/mods/ra/rules/structures.yaml
index 0c634e1dff..c21635ae1c 100644
--- a/mods/ra/rules/structures.yaml
+++ b/mods/ra/rules/structures.yaml
@@ -761,8 +761,9 @@ WEAP:
 	RevealsShroud:
 		Range: 4c0
 	Bib:
-	-RenderBuilding:
-	RenderBuildingWarFactory:
+	WithProductionDoorOverlay:
+		Sequence: idle-top
+		BuildSequence: build-top
 	RallyPoint:
 	Exit@1:
 		SpawnOffset: 213,-128,0