diff --git a/Assets/Scripts/GameObjects/Units/unitData.lua b/Assets/Scripts/GameObjects/Units/unitData.lua
index c413d57..1193310 100644
--- a/Assets/Scripts/GameObjects/Units/unitData.lua
+++ b/Assets/Scripts/GameObjects/Units/unitData.lua
@@ -131,7 +131,8 @@ units = {
 			{id = UnitId.TRADE_CENTER, buildable = true},
 			{id = UnitId.LAB, buildable = true},
 			{id = UnitId.POINT_DEFENSE, buildable = true},
-			{id = UnitId.FORT, buildable = false},
+			{id = UnitId.FORT, buildable = true},
+			{id = UnitId.EXTRACTOR, buildable = true},
 		},
 		unitClass = UnitClass.ENGINEER,
 		unitType = UnitType.HOVER,
diff --git a/Assets/Scripts/Gui/engineerCommands.lua b/Assets/Scripts/Gui/engineerCommands.lua
index c8093f2..5771408 100644
--- a/Assets/Scripts/Gui/engineerCommands.lua
+++ b/Assets/Scripts/Gui/engineerCommands.lua
@@ -46,4 +46,11 @@ gui = {
 		buttonType = ButtonType.BUILD,
 		trigger = 70,
 	},
+	{
+		pos = {x = res.x - 3 * Size.x, y = res.y - 1 * Size.y, z = 0},
+		size = sz,
+		guiType = GuiType.BUTTON,
+		buttonType = ButtonType.BUILD,
+		trigger = 76,
+	},
 }
diff --git a/activeGameState.cpp b/activeGameState.cpp
index d386d50..58d515d 100755
--- a/activeGameState.cpp
+++ b/activeGameState.cpp
@@ -435,8 +435,11 @@ namespace battleship{
 							}
 							else if(ufCtr->isPlacingFrames() && !selectingDestOrient){
                     			castRayToTerrain();
-
 								GameObjectFrame gmObjFr = ufCtr->getGameObjectFrame(0);
+
+								if(gmObjFr.status == GameObjectFrame::NOT_PLACEABLE)
+									return;
+
 								Unit *buildStruct = GameObjectFactory::createUnit(mainPlayer, gmObjFr.getId(), gmObjFr.getPos(), gmObjFr.getRot());
 								mainPlayer->addUnit(buildStruct);
 								targets[0].unit = buildStruct;
diff --git a/external/vb01 b/external/vb01
index 0460303..bd54163 160000
--- a/external/vb01
+++ b/external/vb01
@@ -1 +1 @@
-Subproject commit 04603036101feeaf5a73e37b40ea462aafc0d859
+Subproject commit bd5416328ab10f3cd17b9f0d2def6ae3b7ae8b3e
diff --git a/extractor.cpp b/extractor.cpp
index 23fcb6a..412d4f8 100644
--- a/extractor.cpp
+++ b/extractor.cpp
@@ -23,6 +23,7 @@ namespace battleship{
 			for(ResourceDeposit *dep : deposits)
 				if(dep->getPos().getDistanceFrom(pos) < .001){
 					deposit = dep;
+					deposit->setExtractor(this);
 					break;
 				}
 		}
@@ -33,6 +34,9 @@ namespace battleship{
 	}
 
 	Extractor::~Extractor(){
+		if(deposit)
+			deposit->setExtractor(nullptr);
+
 		removeBar(ammountForeground);
 		removeBar(ammountBackground);
 	}
diff --git a/gameObjectFrameController.cpp b/gameObjectFrameController.cpp
index ca48228..04c593e 100644
--- a/gameObjectFrameController.cpp
+++ b/gameObjectFrameController.cpp
@@ -1,6 +1,9 @@
 #include <solUtil.h>
 
 #include "gameObjectFrameController.h"
+#include "resourceDeposit.h"
+#include "player.h"
+#include "game.h"
 #include "unit.h"
 #include "util.h"
 #include "map.h"
@@ -49,13 +52,34 @@ namespace battleship{
 		}
 	}
 
+	void GameObjectFrameController::snapToObj(GameObjectFrame &s, GameObject::Type type, int unitId, float maxDist){
+		if(s.getType() == GameObject::Type::UNIT && s.getId() == unitId){
+			s.status = GameObjectFrame::NOT_PLACEABLE;
+			vector<Player*> players = Game::getSingleton()->getPlayers();
+			vector<ResourceDeposit*> deposits;
+		
+			for(Player *pl : players){
+				vector<ResourceDeposit*> deps = pl->getResourceDeposits();
+		
+				for(ResourceDeposit *dep : deps)
+					deposits.push_back(dep);
+			}
+
+			for(ResourceDeposit *dep : deposits){
+				Vector3 depPos = dep->getPos();
+
+				if(!dep->getExtractor() && s.getPos().getDistanceFrom(depPos) < maxDist){
+					s.status = GameObjectFrame::PLACEABLE;
+					s.placeAt(depPos);
+					break;
+				}
+			}
+		}
+	}
+
 	//TODO implement terrain evenness check
+	//TODO factor out literal values
 	void GameObjectFrameController::placeGameObjectFrame(int id, Vector3 newPos, float width, float length){
-		GameObjectFrame &s = gameObjectFrames[id];
-
-		if(!rotatingStructure)
-			s.placeAt(newPos);
-
 		Map *map = Map::getSingleton();
 		MeshData meshData = map->getNodeParent()->getChild(0)->getMesh(0)->getMeshBase();
 		MeshData::Vertex *verts = meshData.vertices;
@@ -64,9 +88,9 @@ namespace battleship{
 		float maxUnevenness = .5, unevenness = 0;
 
 		for(int i = 0; i < numVerts; i++){
-			float diffX = fabs(s.getPos().x - verts[i].pos.x);
-			float diffY = fabs(s.getPos().y - verts[i].pos.y);
-			float diffZ = fabs(s.getPos().z - verts[i].pos.z);
+			float diffX = fabs(newPos.x - verts[i].pos.x);
+			float diffY = fabs(newPos.y - verts[i].pos.y);
+			float diffZ = fabs(newPos.z - verts[i].pos.z);
 
 			if(diffX < 0.5 * width && diffZ < 0.5 * length && diffY > unevenness){
 				unevenness = diffY;
@@ -76,18 +100,16 @@ namespace battleship{
 			}
 		}
 
-		Vector4 color;
+		GameObjectFrame &s = gameObjectFrames[id];
 
-		if(unevenness > maxUnevenness){
-			color = Vector4(1, 0, 0, 1);
-			s.status = GameObjectFrame::NOT_PLACEABLE;
-		}
-		else{
-			color = Vector4(0, 1, 0, 1);
-			s.status = GameObjectFrame::PLACEABLE;
-		}
+		if(!rotatingStructure)
+			s.placeAt(newPos);
+
+		s.status = (unevenness < maxUnevenness ? GameObjectFrame::PLACEABLE : GameObjectFrame::NOT_PLACEABLE);
+		snapToObj(s, GameObject::Type::UNIT, 20, 3);
 
 		Material *mat = s.getModel()->getMaterial();
+		Vector4 color = (s.status == GameObjectFrame::NOT_PLACEABLE ? Vector4(1, 0, 0, 1) : Vector4(0, 1, 0, 1));
 		mat->setVec4Uniform("diffuseColor", color);
 	}
 
diff --git a/gameObjectFrameController.h b/gameObjectFrameController.h
index 799d692..a431c68 100644
--- a/gameObjectFrameController.h
+++ b/gameObjectFrameController.h
@@ -35,6 +35,7 @@ namespace battleship{
 			GameObjectFrameController(){}
 			void paintSelect(vb01::Vector3, float, float);
 			void placeGameObjectFrame(int, vb01::Vector3, float, float);
+			void snapToObj(GameObjectFrame&, GameObject::Type, int, float);
 
 			std::vector<GameObjectFrame> gameObjectFrames;
 			vb01::Vector3 paintSelectRowStart, rowDir;
diff --git a/resourceDeposit.h b/resourceDeposit.h
index ff6e425..2d8527e 100644
--- a/resourceDeposit.h
+++ b/resourceDeposit.h
@@ -4,6 +4,8 @@
 #include "gameObject.h"
 
 namespace battleship{
+	class Extractor;
+
 	class ResourceDeposit : public GameObject{
 		public:
 			ResourceDeposit(Player*, int, vb01::Vector3, vb01::Quaternion, int);
@@ -11,8 +13,11 @@ namespace battleship{
 			inline int getAmmount(){return ammount;}
 			inline int getInitAmmount(){return initAmmount;}
 			inline void decreaseAmmount(int amnt){ammount -= amnt;}
+			inline Extractor* getExtractor(){return extractor;}
+			inline void setExtractor(Extractor *e){this->extractor = e;}
 		private:
 			int ammount, initAmmount;
+			Extractor *extractor = nullptr;
 
 			void reinit();
 	};