diff --git a/src/expansion.cr b/src/expansion.cr
index e2f0368..af09ac3 100644
--- a/src/expansion.cr
+++ b/src/expansion.cr
@@ -124,6 +124,8 @@ loop do
     router.handle cmd
   rescue Game::NotEnoughtResources
     printf ">>> Not enought resources <<<\n"
+  rescue Game::InvalidPlaceForBuilding
+    printf ">>> Can't build here <<<\n"
   end
   printf "\n"
 end
diff --git a/src/game/command.cr b/src/game/command.cr
index 3022a1d..5af426e 100644
--- a/src/game/command.cr
+++ b/src/game/command.cr
@@ -14,6 +14,10 @@ module Game
     end
 
     def start(world : World) : Int32
+      tile = world.map.get(@point)
+      if !tile.can_build?
+        raise InvalidPlaceForBuilding.new
+      end
       world.map.set(ConstructionSiteTile.new(@point))
       BUILD_TIME
     end
@@ -80,6 +84,10 @@ module Game
     end
 
     def start(world : World) : Int32
+      tile = world.map.get(@point)
+      if !tile.can_build?
+        raise InvalidPlaceForBuilding.new
+      end
       world.resources.dec(ResourceType::Crystal, CRYSTALS_COST)
       world.map.set(ConstructionSiteTile.new(@point))
       BUILD_TIME
@@ -141,8 +149,12 @@ module Game
     end
 
     def start(world : World) : Int32
-      world.map.set(ConstructionSiteTile.new(@point))
+      tile = world.map.get(@point)
+      if !tile.can_build?
+        raise InvalidPlaceForBuilding.new
+      end
       world.resources.dec(ResourceType::Crystal, CRYSTALS_COST)
+      world.map.set(ConstructionSiteTile.new(@point))
       BUILD_TIME
     end
 
diff --git a/src/game/exception.cr b/src/game/exception.cr
index 2c8e0ab..ba1922f 100644
--- a/src/game/exception.cr
+++ b/src/game/exception.cr
@@ -1,4 +1,10 @@
 module Game
-  class NotEnoughtResources < Exception
+  class BaseException < Exception
+  end
+
+  class NotEnoughtResources < BaseException
+  end
+
+  class InvalidPlaceForBuilding < BaseException
   end
 end
diff --git a/src/game/tile.cr b/src/game/tile.cr
index a343c37..e78f807 100644
--- a/src/game/tile.cr
+++ b/src/game/tile.cr
@@ -40,7 +40,7 @@ module Game
     end
 
     def can_build?
-      @role == TileRole::Plateau
+      has_role(TileRole::Plateau)
     end
   end