diff --git a/lib/entities/buildings/barracks.rb b/lib/entities/buildings/barracks.rb
index e29434f..29ffbac 100644
--- a/lib/entities/buildings/barracks.rb
+++ b/lib/entities/buildings/barracks.rb
@@ -3,7 +3,7 @@ tiles = [
   [false, true,  true,  true,  false],
   [false, true,  true,  true,  false],
   [false, true,  true,  true,  false],
-  [false, true,  true,  true,  false],
+  [false, :path, :path, :path, false],
 ]
 
 IMICRTS::Entity.define_entity(:barracks, :building, 400, "Builds and soldiers", tiles) do |entity|
diff --git a/lib/entities/buildings/construction_yard.rb b/lib/entities/buildings/construction_yard.rb
index d4756e7..ab05f06 100644
--- a/lib/entities/buildings/construction_yard.rb
+++ b/lib/entities/buildings/construction_yard.rb
@@ -1,9 +1,9 @@
 tiles = [
   [false, false, false, false, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
+  [false, true,  true,  true,  false],
+  [false, true,  true,  true,  false],
+  [false, true,  true,  true,  false],
+  [false, :path, :path, :path, false],
 ]
 
 IMICRTS::Entity.define_entity(:construction_yard, :building, 2_000, "Provides radar and builds construction workers", tiles) do |entity|
diff --git a/lib/entities/buildings/power_plant.rb b/lib/entities/buildings/power_plant.rb
index eb5b599..ea371a6 100644
--- a/lib/entities/buildings/power_plant.rb
+++ b/lib/entities/buildings/power_plant.rb
@@ -3,7 +3,7 @@ tiles = [
   [false, false, true,  false, false],
   [false, false, true,  false, false],
   [false, false, true,  false, false],
-  [false, false, true,  false, false],
+  [false, false, :path, false, false],
 ]
 
 IMICRTS::Entity.define_entity(:power_plant, :building, 800, "Generates power", tiles) do |entity|
diff --git a/lib/entities/buildings/refinery.rb b/lib/entities/buildings/refinery.rb
index 34fbcc8..9e6d9ca 100644
--- a/lib/entities/buildings/refinery.rb
+++ b/lib/entities/buildings/refinery.rb
@@ -3,7 +3,7 @@ tiles = [
   [false, true,  true,  false, false],
   [false, true,  true,  true,  false],
   [false, true,  true,  true,  false],
-  [false, false, true,  true,  false],
+  [false, false, :path, :path, false],
 ]
 
 IMICRTS::Entity.define_entity(:refinery, :building, 1_400, "Generates credits", tiles) do |entity|
diff --git a/lib/entities/buildings/war_factory.rb b/lib/entities/buildings/war_factory.rb
index a2438ae..69d8490 100644
--- a/lib/entities/buildings/war_factory.rb
+++ b/lib/entities/buildings/war_factory.rb
@@ -1,9 +1,9 @@
 tiles = [
   [false, false, false, false, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
-  [false, true,  true,  true, false],
+  [false, true,  true,  true,  false],
+  [false, true,  true,  true,  false],
+  [false, true,  true,  true,  false],
+  [false, :path, :path, :path, false],
 ]
 
 IMICRTS::Entity.define_entity(:war_factory, :building, 2_000, "Builds units", tiles) do |entity|
diff --git a/lib/map.rb b/lib/map.rb
index bc55c62..239673d 100644
--- a/lib/map.rb
+++ b/lib/map.rb
@@ -104,7 +104,7 @@ class IMICRTS
     end
 
     class Tile
-      attr_accessor :position, :grid_position, :image, :visible, :entity, :type
+      attr_accessor :position, :grid_position, :image, :visible, :entity, :reserved, :type
       def initialize(position:, image:, visible:, type:, tile_size:)
         @position = position
         @grid_position = position.clone
@@ -114,6 +114,7 @@ class IMICRTS
         @image = image
         @visible = visible
         @entity = nil
+        @reserved = nil
         @type = type
       end
     end
diff --git a/lib/tools/place_entity.rb b/lib/tools/place_entity.rb
index fd56f43..de396e3 100644
--- a/lib/tools/place_entity.rb
+++ b/lib/tools/place_entity.rb
@@ -10,8 +10,8 @@ class IMICRTS
     end
 
     def draw
-      each_tile(vector_to_grid(@game.window.mouse)) do |x, y, tile|
-        if tile.entity || tile.type != :ground || @director.map.ore_at(x, y) # tile unavailable
+      each_tile(vector_to_grid(@game.window.mouse)) do |tile, _data, x, y|
+        if tile.entity || tile.reserved || tile.type != :ground || @director.map.ore_at(x, y) # tile unavailable
           Gosu.draw_rect(
             tile.position.x + 2, tile.position.y + 2,
             @director.map.tile_size - 4, @director.map.tile_size - 4,
@@ -57,8 +57,12 @@ class IMICRTS
         position: CyberarmEngine::Vector.new(position.x, position.y, ZOrder::BUILDING)
       )
 
-      each_tile(vector) do |x, y, tile|
-        tile.entity = ent
+      each_tile(vector) do |tile, space_required|
+        if space_required == true
+          tile.entity = ent
+        else
+          tile.reserved = ent
+        end
       end
 
       cancel_tool
@@ -73,8 +77,8 @@ class IMICRTS
         ent = Entity.get(@entity)
         origin = (tile.grid_position - 2)
 
-        each_tile(vector) do |x, y, tile|
-          if tile.entity || tile.type != :ground || @director.map.ore_at(x, y)
+        each_tile(vector) do |tile, _data, x, y|
+          if tile.entity || tile.reserved || tile.type != :ground || @director.map.ore_at(x, y)
             useable = false
             break
           end
@@ -97,7 +101,7 @@ class IMICRTS
 
             other_tile = @director.map.tile_at(origin.x + x, origin.y + y)
             if other_tile
-              block.call(origin.x + x, origin.y + y, other_tile)
+              block.call(other_tile, space_required, origin.x + x, origin.y + y)
             end
           end
         end