diff --git a/Assets/Scripts/Core/player.lua b/Assets/Scripts/Core/player.lua
index cf4ba0f..748e28e 100644
--- a/Assets/Scripts/Core/player.lua
+++ b/Assets/Scripts/Core/player.lua
@@ -38,7 +38,7 @@ function Player:trainEngineers()
 	dirToCenter = Vector3:new(0, 0, 0):subtr(fort:getPos()):norm()
 
 	while #fort:getQueue() + #self:getUnitsByClass(UnitClass.ENGINEER, -1) < self.numStartEngis do
-		fort:appendToQueue(UnitId.ENGINEER)
+		fort:appendToQueue(0)
 	end
 
 	return #self:getUnitsByClass(UnitClass.ENGINEER, -1) == self.numStartEngis
@@ -132,7 +132,7 @@ function Player:buildHarvester()
 	factory = landFactories[1]:toFactory()
 
 	if #factory:getQueue() == 0 then
-		factory:appendToQueue(UnitId.RESOURCE_ROVER)
+		factory:appendToQueue(3)
 	end
 
 	return false
@@ -157,10 +157,10 @@ function Player:startHarvesting()
 	return true
 end
 
-function Player:buildTaskforceUnitGroup(numUnits, currNumUnits, factory, unitId)
+function Player:buildTaskforceUnitGroup(numUnits, currNumUnits, factory, buId)
 	if currNumUnits < numUnits then
 		for i = 1, numUnits - currNumUnits do
-			factory:appendToQueue(unitId)
+			factory:appendToQueue(buId)
 		end
 	end
 end
@@ -175,9 +175,9 @@ function Player:buildTaskforce()
 	currLandFactories = self:getUnitsByClass(UnitClass.LAND_FACTORY, -1)
 
 	for i = 1, #currLandFactories do
-		currNumWarMechs = currNumWarMechs + currLandFactories[i]:toFactory():getNumQueueUnitsById(UnitId.WAR_MECH)
-		currNumTanks = currNumTanks + currLandFactories[i]:toFactory():getNumQueueUnitsById(UnitId.TANK)
-		currNumArtillery = currNumArtillery + currLandFactories[i]:toFactory():getNumQueueUnitsById(UnitId.ARTILLERY)
+		currNumWarMechs = currNumWarMechs + currLandFactories[i]:toFactory():getNumQueueUnitsById(0)
+		currNumTanks = currNumTanks + currLandFactories[i]:toFactory():getNumQueueUnitsById(1)
+		currNumArtillery = currNumArtillery + currLandFactories[i]:toFactory():getNumQueueUnitsById(2)
 	end
 
 	numWarMechs = self.numDefWarMechs + self.numTaskForceWarMechs
@@ -190,9 +190,9 @@ function Player:buildTaskforce()
 
 	landFactory = currLandFactories[1]:toFactory()
 
-	self:buildTaskforceUnitGroup(numWarMechs, currNumWarMechs, landFactory, UnitId.WAR_MECH)
-	self:buildTaskforceUnitGroup(numTanks, currNumTanks, landFactory, UnitId.TANK)
-	self:buildTaskforceUnitGroup(numArtillery, currNumArtillery, landFactory, UnitId.ARTILLERY)
+	self:buildTaskforceUnitGroup(numWarMechs, currNumWarMechs, landFactory, 0)
+	self:buildTaskforceUnitGroup(numTanks, currNumTanks, landFactory, 1)
+	self:buildTaskforceUnitGroup(numArtillery, currNumArtillery, landFactory, 2)
 
 	return false
 end
diff --git a/Assets/Scripts/GameObjects/Units/unitData.lua b/Assets/Scripts/GameObjects/Units/unitData.lua
index 364ee66..27d0022 100644
--- a/Assets/Scripts/GameObjects/Units/unitData.lua
+++ b/Assets/Scripts/GameObjects/Units/unitData.lua
@@ -73,6 +73,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 1
 	},
 	{
@@ -96,6 +97,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 2
 	},
 	{
@@ -119,12 +121,21 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 2
 	},
 	{
 		weapons = {
 			{type = WeaponClass.HITSCAN, rateOfFire = 2000, fireSfx = PATH .. 'Sounds/Units/WarMechs/fire.ogg', damage = 20, maxRange = 8},
 		},
+		buildableUnits = {
+			{id = UnitId.LAND_FACTORY, buildable = true},
+			{id = UnitId.NAVAL_FACTORY, buildable = true},
+			{id = UnitId.MARKET, buildable = true},
+			{id = UnitId.LAB, buildable = true},
+			{id = UnitId.POINT_DEFENSE, buildable = true},
+			{id = UnitId.FORT, buildable = true},
+		},
 		unitClass = UnitClass.ENGINEER,
 		unitType = UnitType.HOVER,
 		armor = {ArmorType.MECHANIC},
@@ -140,6 +151,7 @@ units = {
 		name = 'Engineer',
 		basePath = PATH .. vehiclePrefix .. 'Engineers/',
 		meshPath = 'engineer.xml',
+		guiScreen = 'engineerCommands.lua',
 		selectionSfx = PATH .. 'Sounds/Units/Engineers/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 		speed = .1,
@@ -169,6 +181,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -193,6 +206,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -219,6 +233,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -242,6 +257,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -266,6 +282,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -289,6 +306,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -312,6 +330,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -334,6 +353,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -365,6 +385,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -403,6 +424,7 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
@@ -434,9 +456,16 @@ units = {
 		destinationOffset = .1,
 		anglePrecision = .1,
 		maxTurnAngle = .1,
+		guiScreen = '',
 		garrisonCategory = 3
 	},
 	{
+		buildableUnits = {
+			{id = UnitId.WAR_MECH, buildable = true}, 
+			{id = UnitId.TANK, buildable = true}, 
+			{id = UnitId.ARTILLERY, buildable = true}, 
+			{id = UnitId.RESOURCE_ROVER, buildable = true}
+		},
 		unitClass = UnitClass.LAND_FACTORY,
 		unitType = UnitType.LAND,
 		isVehicle = false,
@@ -449,6 +478,7 @@ units = {
 		name = 'Land factory',
 		basePath = PATH .. structurePrefix .. 'LandFactories/',
 		meshPath = 'landFactory.xml',
+		guiScreen = 'landFactoryCommands.lua',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
@@ -465,6 +495,7 @@ units = {
 		name = 'Naval factory',
 		basePath = PATH .. structurePrefix .. 'NavalFactories/',
 		meshPath = 'navalFactory.xml',
+		guiScreen = 'navalFactoryCommands.lua',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
@@ -482,6 +513,7 @@ units = {
 		basePath = PATH .. structurePrefix .. 'Markets/',
 		meshPath = 'market.xml',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
+		guiScreen = '',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
 	{
@@ -500,6 +532,7 @@ units = {
 		name = 'Lab',
 		basePath = PATH .. structurePrefix .. 'Labs/',
 		meshPath = 'lab.xml',
+		guiScreen = '',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
@@ -518,6 +551,7 @@ units = {
 		basePath = PATH .. structurePrefix .. 'PointDefenses/',
 		meshPath = 'pointDefense.xml',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
+		guiScreen = '',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
 	{
@@ -536,6 +570,7 @@ units = {
 		basePath = PATH .. structurePrefix .. 'Extractors/',
 		meshPath = 'extractor.xml',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
+		guiScreen = '',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
 	{
@@ -551,10 +586,12 @@ units = {
 		name = 'Refinery',
 		basePath = PATH .. structurePrefix .. 'Refineries/',
 		meshPath = 'refinery.xml',
+		guiScreen = '',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
 	{
+		buildableUnits = {{id = UnitId.ENGINEER, buildable = true}},
 		unitClass = UnitClass.FORT,
 		unitType = UnitType.LAND,
 		isVehicle = false,
@@ -567,6 +604,7 @@ units = {
 		name = 'Fort',
 		basePath = PATH .. structurePrefix .. 'Forts/',
 		meshPath = 'fort.xml',
+		guiScreen = 'fortCommands.lua',
 		selectionSfx = PATH .. 'Sounds/Units/Sample/selection.ogg',
 		deathSfx = PATH .. 'Sounds/SFX/Explosions/explosion01.ogg',
 	},
diff --git a/Assets/Scripts/Gui/engineerCommands.lua b/Assets/Scripts/Gui/engineerCommands.lua
index 8fe31c5..d9cd565 100644
--- a/Assets/Scripts/Gui/engineerCommands.lua
+++ b/Assets/Scripts/Gui/engineerCommands.lua
@@ -9,7 +9,6 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 76,
-		structureId = UnitId.LAND_FACTORY 
 	},
 	{
 		pos = {x = res.x - Size.x - 200, y = res.y - 200},
@@ -18,7 +17,6 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 78,
-		structureId = UnitId.NAVAL_FACTORY 
 	},
 	{
 		pos = {x = res.x - 2 * Size.x - 200, y = res.y - 200},
@@ -27,7 +25,6 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 77,
-		structureId = UnitId.MARKET
 	},
 	{
 		pos = {x = res.x - 3 * Size.x - 200, y = res.y - 200},
@@ -36,7 +33,6 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 84,
-		structureId = UnitId.LAB
 	},
 	{
 		pos = {x = res.x - 4 * Size.x - 200, y = res.y - 200},
@@ -45,7 +41,6 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 68,
-		structureId = UnitId.POINT_DEFENSE
 	},
 	{
 		pos = {x = res.x - 5 * Size.x - 200, y = res.y - 200},
@@ -54,6 +49,5 @@ gui = {
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.BUILD,
 		trigger = 70,
-		structureId = UnitId.FORT 
 	},
 }
diff --git a/Assets/Scripts/Gui/fortCommands.lua b/Assets/Scripts/Gui/fortCommands.lua
index a9f985e..2600775 100644
--- a/Assets/Scripts/Gui/fortCommands.lua
+++ b/Assets/Scripts/Gui/fortCommands.lua
@@ -8,7 +8,6 @@ gui = {
 		imagePath = '',
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.FORT_TRAIN,
-		trigger = 82,
-		unitId = UnitId.ENGINEER
+		trigger = 82
 	},
 }
diff --git a/Assets/Scripts/Gui/landFactoryCommands.lua b/Assets/Scripts/Gui/landFactoryCommands.lua
index abece5c..8ad889f 100644
--- a/Assets/Scripts/Gui/landFactoryCommands.lua
+++ b/Assets/Scripts/Gui/landFactoryCommands.lua
@@ -1,4 +1,3 @@
-numGui = 2
 res = graphics.resolution
 Size = {x = 100, y = 100}
 
@@ -9,8 +8,7 @@ gui = {
 		imagePath = '',
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.LAND_FACTORY_TRAIN,
-		trigger = 84,
-		unitId = UnitId.TANK
+		trigger = 87
 	},
 	{
 		pos = {x = res.x - Size.x - 200, y = res.y - 200},
@@ -18,7 +16,14 @@ gui = {
 		imagePath = '',
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.LAND_FACTORY_TRAIN,
-		trigger = 65,
-		unitId = UnitId.ARTILLERY
+		trigger = 84
+	},
+	{
+		pos = {x = res.x - 2 * Size.x - 200, y = res.y - 200},
+		size = Size,
+		imagePath = '',
+		guiType = GuiType.BUTTON,
+		buttonType = ButtonType.LAND_FACTORY_TRAIN,
+		trigger = 65
 	}
 }
diff --git a/Assets/Scripts/Gui/navalFactoryCommands.lua b/Assets/Scripts/Gui/navalFactoryCommands.lua
index 2ffedbd..652031d 100644
--- a/Assets/Scripts/Gui/navalFactoryCommands.lua
+++ b/Assets/Scripts/Gui/navalFactoryCommands.lua
@@ -1,4 +1,3 @@
-numGui = 1
 res = graphics.resolution
 
 gui = {
@@ -8,7 +7,6 @@ gui = {
 		imagePath = '',
 		guiType = GuiType.BUTTON,
 		buttonType = ButtonType.NAVAL_FACTORY_TRAIN,
-		trigger = 66,
-		unitId = UnitId.SCOUT_TRANSPORT 
+		trigger = 66
 	}
 }
diff --git a/activeGameState.cpp b/activeGameState.cpp
index 4692a9f..8cbdb43 100755
--- a/activeGameState.cpp
+++ b/activeGameState.cpp
@@ -161,6 +161,7 @@ namespace battleship{
 
 		ConcreteGuiManager::getSingleton()->removeAllButtons();
 		buttons.clear();
+		unitGuiScreen = "";
 	}
 
 	bool ActiveGameState::selectedUnitsAmongst(vector<Unit*> units){
@@ -193,6 +194,7 @@ namespace battleship{
 			guiManager->getText("wealth"),
 			guiManager->getText("research")
 		};
+		vector<Unit*> selUnits = mainPlayer->getSelectedUnits();
 		
 
         for (Unit *u : units) {
@@ -200,16 +202,11 @@ namespace battleship{
 			   	Vector3 dragboxSize = ((Quad*)dragboxNode->getMesh(0))->getSize();
 				Vector3 dragboxOrigin = dragboxNode->getPosition(), dragboxEnd = dragboxOrigin + dragboxSize;
             	Vector2 pos = u->getScreenPos();
+				string guiScreen = u->getBuildableUnitGuiScreen();
 
-				if(buttons.empty()){
-					if(selectedUnitsAmongst(mainPlayer->getUnitsByClass(UnitClass::ENGINEER)))
-						guiManager->readLuaScreenScript("engineerCommands.lua", buttons, listboxes, checkboxes, sliders, textboxes, guiRects, texts);
-					else if(selectedUnitsAmongst(mainPlayer->getUnitsByClass(UnitClass::FORT)))
-						guiManager->readLuaScreenScript("fortCommands.lua", buttons, listboxes, checkboxes, sliders, textboxes, guiRects, texts);
-					else if(selectedUnitsAmongst(mainPlayer->getUnitsByClass(UnitClass::LAND_FACTORY)))
-						guiManager->readLuaScreenScript("landFactoryCommands.lua", buttons, listboxes, checkboxes, sliders, textboxes, guiRects, texts);
-					else if(selectedUnitsAmongst(mainPlayer->getUnitsByClass(UnitClass::NAVAL_FACTORY)))
-						guiManager->readLuaScreenScript("navalFactoryCommands.lua", buttons, listboxes, checkboxes, sliders, textboxes, guiRects, texts);
+				if(!selUnits.empty() && u == selUnits[0] && guiScreen != "" && guiScreen != unitGuiScreen){
+					guiManager->readLuaScreenScript(u->getBuildableUnitGuiScreen(), buttons, listboxes, checkboxes, sliders, textboxes, guiRects, texts);
+					unitGuiScreen = guiScreen;
 				}
 
                 if(isSelectionBox && fabs(pos.x - dragboxOrigin.x) < .5 * dragboxSize.x && fabs(pos.y - dragboxOrigin.y) < .5 * dragboxSize.y){
diff --git a/activeGameState.h b/activeGameState.h
index 1b01121..6de8d1b 100755
--- a/activeGameState.h
+++ b/activeGameState.h
@@ -47,6 +47,7 @@ namespace battleship{
 
         GuiAppState *guiState;
         Player *mainPlayer;
+		std::string unitGuiScreen = "";
 		GameObject *gameObjHoveredOn = nullptr;
 		vb01::Node *dragboxNode = nullptr;
 		vb01::Vector2 clickPoint;
diff --git a/buildButton.cpp b/buildButton.cpp
index e36c9ec..29f57e0 100644
--- a/buildButton.cpp
+++ b/buildButton.cpp
@@ -1,8 +1,12 @@
 #include "buildButton.h"
 #include "gameManager.h"
 #include "gameObject.h"
+#include "unit.h"
+#include "activeGameState.h"
+#include "buildableUnit.h"
 #include "gameObjectFrameController.h"
 
+#include <stateManager.h>
 #include <solUtil.h>
 
 namespace battleship{
@@ -12,13 +16,18 @@ namespace battleship{
 	using namespace vb01Gui;
 	using namespace gameBase;
 
-	BuildButton::BuildButton(Vector2 pos, Vector2 size, int structureId, string name, int trigger, string imagePath) : UnitButton(pos, size, name, GameManager::getSingleton()->getPath() + "Fonts/batang.ttf", trigger, imagePath){
-		this->structureId = structureId;
-	}
+	BuildButton::BuildButton(Vector2 pos, Vector2 size, string name, int trigger, string imagePath, int uid, int slId) : 
+		UnitButton(pos, size, name, GameManager::getSingleton()->getPath() + "Fonts/batang.ttf", trigger, imagePath, uid), slotId(slId){}
 
 	void BuildButton::onClick(){
-		GameObjectFrameController *ufCtr = GameObjectFrameController::getSingleton();
-		ufCtr->addGameObjectFrame(GameObjectFrame(structureId, GameObject::Type::UNIT));
-		ufCtr->setPlacingFrames(true);
+		ActiveGameState *activeState = (ActiveGameState*)(GameManager::getSingleton()->getStateManager()->getAppStateByType((int)AppStateType::ACTIVE_STATE));
+		Player *player = activeState->getPlayer();
+		Unit* builder = player->getUnitsById(unitId)[0];
+
+		if(builder->getBuildableUnit(slotId).buildable){
+			GameObjectFrameController *ufCtr = GameObjectFrameController::getSingleton();
+			ufCtr->addGameObjectFrame(GameObjectFrame(builder->getBuildableUnit(slotId).id, GameObject::Type::UNIT));
+			ufCtr->setPlacingFrames(true);
+		}
 	}
 }
diff --git a/buildButton.h b/buildButton.h
index ae4802b..b4cd97b 100644
--- a/buildButton.h
+++ b/buildButton.h
@@ -6,10 +6,10 @@
 namespace battleship{
 	class BuildButton : public UnitButton{
 		public:
-			BuildButton(vb01::Vector2, vb01::Vector2, int, std::string, int, std::string);
+			BuildButton(vb01::Vector2, vb01::Vector2, std::string, int, std::string, int, int);
 			void onClick();
 		private:
-			int structureId;
+			int slotId;
 	};
 }
 
diff --git a/concreteGuiManager.cpp b/concreteGuiManager.cpp
index b48b393..404e6ba 100644
--- a/concreteGuiManager.cpp
+++ b/concreteGuiManager.cpp
@@ -163,30 +163,34 @@ namespace battleship{
 			}
 			case BUILD:
 			{
-				int strId = guiTable["structureId"];
+				int unitId = SOL_LUA_STATE["UnitId"]["ENGINEER"];
+				int strId = SOL_LUA_STATE["units"][unitId + 1]["buildableUnits"][guiId + 1]["id"];
 				string buttonName = SOL_LUA_STATE["units"][strId + 1]["name"];
-				button = new BuildButton(pos, size, strId, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"]);
+				button = new BuildButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], unitId, guiId);
 				break;
 			}
 			case LAND_FACTORY_TRAIN:
 			{
-				int unitId = guiTable["unitId"];
+				int facId = SOL_LUA_STATE["UnitId"]["LAND_FACTORY"];
+				int unitId = SOL_LUA_STATE["units"][facId + 1]["buildableUnits"][guiId + 1]["id"];
 				string buttonName = SOL_LUA_STATE["units"][unitId + 1]["name"];
-				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], (int)SOL_LUA_STATE["UnitId"]["LAND_FACTORY"], unitId);
+				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], facId, guiId);
 				break;
 			}
 			case NAVAL_FACTORY_TRAIN:
 			{
-				int unitId = guiTable["unitId"];
+				int facId = SOL_LUA_STATE["UnitId"]["NAVAL_FACTORY"];
+				int unitId = SOL_LUA_STATE["units"][facId + 1]["buildableUnits"][guiId + 1]["id"];
 				string buttonName = SOL_LUA_STATE["units"][unitId + 1]["name"];
-				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], (int)SOL_LUA_STATE["UnitId"]["NAVAL_FACTORY"], unitId);
+				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], facId, guiId);
 				break;
 			}
 			case FORT_TRAIN:
 			{
-				int unitId = guiTable["unitId"];
+				int facId = SOL_LUA_STATE["UnitId"]["FORT"];
+				int unitId = SOL_LUA_STATE["units"][facId + 1]["buildableUnits"][guiId + 1]["id"];
 				string buttonName = SOL_LUA_STATE["units"][unitId + 1]["name"];
-				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], (int)SOL_LUA_STATE["UnitId"]["FORT"], unitId);
+				button = new TrainButton(pos, size, buttonName, (int)guiTable["trigger"], (string)guiTable["imagePath"], facId, guiId);
 				break;
 			}
 			case STATISTICS:
diff --git a/factory.cpp b/factory.cpp
index 4554904..0c02245 100644
--- a/factory.cpp
+++ b/factory.cpp
@@ -1,5 +1,6 @@
 #include "factory.h"
 #include "player.h"
+#include "game.h"
 #include "gameObjectFactory.h"
 #include "activeGameState.h"
 
@@ -24,6 +25,14 @@ namespace battleship{
 			train();
 	}
 
+	//TODO replace repetetive string literals
+	void Factory::initProperties(){
+		Structure::initProperties();
+		Game *game = Game::getSingleton();
+		vector<int> currTechs = player->getTechnologies();
+
+	}
+
 	int Factory::getNumQueueUnitsById(int unitId){
 		int numUnits = 0;
 
@@ -34,6 +43,11 @@ namespace battleship{
 		return numUnits;
 	}
 
+	void Factory::appendToQueue(int buId){
+		if(buId < buildableUnits.size() && buildableUnits[buId].buildable)
+			unitQueue.push_back(buildableUnits[buId].id);
+	}
+
 	void Factory::train(){
 		bool training = !unitQueue.empty();
 		buildStatusForeground->setVisible(training);
diff --git a/factory.h b/factory.h
index 851ae22..586eab8 100644
--- a/factory.h
+++ b/factory.h
@@ -19,14 +19,14 @@ namespace battleship{
 			~Factory(){}
 			void update();
 			int getNumQueueUnitsById(int);
-			void appendToQueue(int uid){unitQueue.push_back(uid);}
+			void appendToQueue(int);
 			inline std::vector<int> getQueue(){return unitQueue;}
 		private:
-			const int MAX_LEN_QUEUE = 10;
-			int trainingStatus = 0;
-			vb01::s64 lastTrainTime = 0;
 			std::vector<int> unitQueue;
+			int maxLenQueue, trainingStatus = 0;
+			vb01::s64 lastTrainTime = 0;
 
+			void initProperties();
 			void train();
 	};
 }
diff --git a/trainButton.cpp b/trainButton.cpp
index 436c84c..bab5d5e 100644
--- a/trainButton.cpp
+++ b/trainButton.cpp
@@ -1,5 +1,6 @@
 #include "trainButton.h"
 #include "activeGameState.h"
+#include "buildableUnit.h"
 #include "factory.h"
 
 #include <stateManager.h>
@@ -10,19 +11,17 @@ namespace battleship{
 	using namespace vb01;
 	using namespace gameBase;
 
-	TrainButton::TrainButton(Vector2 pos, Vector2 size, string name, int trigger, string imagePath, int fid, int tuid) : 
-		factoryId(fid), 
-		trainableUnitId(tuid), 
-		UnitButton(pos, size, name, GameManager::getSingleton()->getPath() + "Fonts/batang.ttf", trigger, imagePath){}
+	TrainButton::TrainButton(Vector2 pos, Vector2 size, string name, int trigger, string imagePath, int uid, int slId) :
+		UnitButton(pos, size, name, GameManager::getSingleton()->getPath() + "Fonts/batang.ttf", trigger, imagePath, uid),
+		slotId(slId) {}
 
 	void TrainButton::onClick(){
 		ActiveGameState *activeState = (ActiveGameState*)(GameManager::getSingleton()->getStateManager()->getAppStateByType((int)AppStateType::ACTIVE_STATE));
 		Player *player = activeState->getPlayer();
-		UnitClass facClass = (UnitClass)generateView()["units"][factoryId + 1]["unitClass"]; 
-		vector<Unit*> selUnits = player->getSelectedUnits(), factories = player->getUnitsByClass(facClass);
+		vector<Unit*> selUnits = player->getSelectedUnits(), factories = player->getUnitsById(unitId);
 
 		for(Unit *fac : factories)
-			if(find(selUnits.begin(), selUnits.end(), fac) != selUnits.end())
-				((Factory*)fac)->appendToQueue(trainableUnitId);
+			if(fac->getBuildableUnit(slotId).buildable && find(selUnits.begin(), selUnits.end(), fac) != selUnits.end())
+				((Factory*)fac)->appendToQueue(slotId);
 	}
 }
diff --git a/trainButton.h b/trainButton.h
index e600dd1..149c906 100644
--- a/trainButton.h
+++ b/trainButton.h
@@ -9,7 +9,7 @@ namespace battleship{
 			TrainButton(vb01::Vector2, vb01::Vector2, std::string, int, std::string, int, int);
 			void onClick();
 		private:
-			int factoryId, trainableUnitId;
+			int slotId;
 	};
 }
 
diff --git a/unit.cpp b/unit.cpp
index 2c34719..27b67f0 100755
--- a/unit.cpp
+++ b/unit.cpp
@@ -16,6 +16,8 @@
 #include "vehicle.h"
 #include "gameObjectFactory.h"
 #include "activeGameState.h"
+#include "gameManager.h"
+#include "projectile.h"
 #include "defConfigs.h"
 #include "pathfinder.h"
 #include "ability.h"
@@ -171,6 +173,20 @@ namespace battleship{
 				armorTypes.push_back(arm);
 			}
 		}
+
+		tblName = "buildableUnits";
+		sol::optional<sol::table> bu = unitTable[tblName];
+
+		if(bu != sol::nullopt){
+			SOL_LUA_VIEW.script("numBuildableUnits = #units[" + to_string(id + 1) + "]." + tblName);
+			int numBuildableUnits = SOL_LUA_VIEW["numBuildableUnits"];
+			buildableUnitGuiScreen = unitTable["guiScreen"];
+
+			for(int i = 0; i < numBuildableUnits; i++){
+				sol::table buTable = unitTable[tblName][i + 1];
+				buildableUnits.push_back(BuildableUnit(buTable["id"], buTable["buildable"]));
+			}
+		}
 	}
 
 	void Unit::initWeapons(){
diff --git a/unit.h b/unit.h
index 2052d9e..815c6f9 100755
--- a/unit.h
+++ b/unit.h
@@ -8,9 +8,8 @@
 
 #include <solUtil.h>
 
-#include "gameManager.h"
 #include "gameObject.h"
-#include "projectile.h"
+#include "buildableUnit.h"
 
 namespace sf{
 	class SoundBuffer;
@@ -31,8 +30,9 @@ namespace battleship{
 	class Structure;
 	class Factory;
 	class Cruiser;
-	class PointDefense;
 	class Engineer;
+	class PointDefense;
+	class Projectile;
     
     struct Order {
         enum class TYPE {ATTACK, BUILD, MOVE, GARRISON, EJECT, PATROL, LAUNCH, SUPPLY, HACK};
@@ -149,6 +149,8 @@ namespace battleship{
 		inline bool isTargetToTheRight(vb01::Vector3 dir, vb01::Vector3 lv){return lv.getAngleBetween(dir) > vb01::PI / 2;}
 		inline Order getOrder(int i){return orders[i];}
 		inline int getNumOrders(){return orders.size();}
+		inline std::string getBuildableUnitGuiScreen(){return buildableUnitGuiScreen;}
+		inline BuildableUnit getBuildableUnit(int i){return buildableUnits[i];}
     private:
 		void renderOrderLine(bool);
         void updateScreenCoordinates();
@@ -165,12 +167,14 @@ namespace battleship{
         UnitClass unitClass;
         UnitType type;
         std::vector<Order> orders;
+		std::string buildableUnitGuiScreen = "";
         int health, maxHealth, playerId, lenHpBar = 200;
-        s64 orderLineDispTime = 0, lastFireTime = 0;
+		vb01::s64 orderLineDispTime = 0, lastFireTime = 0;
         float lineOfSight;
-		std::vector<GarrisonSlot> garrisonSlots;
 		std::vector<Armor> armorTypes;
 		std::vector<Weapon*> weapons;
+		std::vector<GarrisonSlot> garrisonSlots;
+		std::vector<BuildableUnit> buildableUnits;
 		State state = State::STAND_GROUND;
 
 		std::vector<Player*> getSelectingPlayers();
diff --git a/unitButton.cpp b/unitButton.cpp
index 3a0d8ba..bb568a1 100644
--- a/unitButton.cpp
+++ b/unitButton.cpp
@@ -10,7 +10,7 @@ namespace battleship{
 	using namespace vb01Gui;
 	using namespace gameBase;
 
-	UnitButton::UnitButton(Vector2 pos, Vector2 size, string name, string fontPath, int trigger, string imagePath) : Button(pos, size, name, fontPath, trigger, true, imagePath){
+	UnitButton::UnitButton(Vector2 pos, Vector2 size, string name, string fontPath, int trigger, string imagePath, int uid) : Button(pos, size, name, fontPath, trigger, true, imagePath), unitId(uid){
 		StateManager *stateManager = GameManager::getSingleton()->getStateManager();
 		ActiveGameState *activeState = (ActiveGameState*)stateManager->getAppStateByType((int)AppStateType::ACTIVE_STATE);
 
diff --git a/unitButton.h b/unitButton.h
index 696ae1e..db682e5 100644
--- a/unitButton.h
+++ b/unitButton.h
@@ -8,8 +8,9 @@ namespace battleship{
 
 	class UnitButton : public vb01Gui::Button{
 		public:
-			UnitButton(vb01::Vector2, vb01::Vector2, std::string, std::string, int, std::string);
+			UnitButton(vb01::Vector2, vb01::Vector2, std::string, std::string, int, std::string, int);
 		protected:
+			int unitId;
 			std::vector<Unit*> units;
 	};
 }