diff --git a/library/include/modules/EventManager.h b/library/include/modules/EventManager.h
index bd7a91259..b83300c89 100644
--- a/library/include/modules/EventManager.h
+++ b/library/include/modules/EventManager.h
@@ -7,6 +7,9 @@
 #include "ColorText.h"
 #include "PluginManager.h"
 #include "Console.h"
+#include "DataDefs.h"
+
+#include <df/coord.h>
 
 namespace DFHack {
     namespace EventManager {
@@ -63,4 +66,18 @@ namespace DFHack {
     }
 }
 
+namespace std {
+    template <>
+    struct hash<df::coord> {
+        std::size_t operator()(const df::coord& c) const {
+            size_t r = 17;
+            const size_t m = 65537;
+            r = m*(r+c.x);
+            r = m*(r+c.y);
+            r = m*(r+c.z);
+            return r;
+        }
+    };
+}
+
 #endif
diff --git a/library/modules/EventManager.cpp b/library/modules/EventManager.cpp
index 556cccc65..4ad3d89c0 100644
--- a/library/modules/EventManager.cpp
+++ b/library/modules/EventManager.cpp
@@ -151,7 +151,7 @@ static int32_t nextBuilding;
 static unordered_set<int32_t> buildings;
 
 //construction
-static unordered_set<df::construction*> constructions;
+static unordered_map<df::coord, df::construction> constructions;
 static bool gameLoaded;
 
 //invasion
@@ -510,28 +510,35 @@ static void manageConstructionEvent(color_ostream& out) {
     unordered_set<df::construction*> constructionsNow(df::global::world->constructions.begin(), df::global::world->constructions.end());
     
     multimap<Plugin*,EventHandler> copy(handlers[EventType::CONSTRUCTION].begin(), handlers[EventType::CONSTRUCTION].end());
+    unordered_set<df::coord> toDelete;
     for ( auto a = constructions.begin(); a != constructions.end(); a++ ) {
-        df::construction* construction = *a;
-        if ( constructionsNow.find(construction) != constructionsNow.end() )
+        df::construction& construction = (*a).second;
+        if ( df::construction::find(construction.pos) != NULL )
             continue;
+        //construction removed
+        toDelete.insert((*a).first);
         for ( auto b = copy.begin(); b != copy.end(); b++ ) {
             EventHandler handle = (*b).second;
-            handle.eventHandler(out, (void*)construction);
+            handle.eventHandler(out, (void*)&construction);
         }
     }
-
+    
+    for ( auto a = toDelete.begin(); a != toDelete.end(); a++ ) {
+        constructions.erase(*a);
+    }
+    
     for ( auto a = constructionsNow.begin(); a != constructionsNow.end(); a++ ) {
         df::construction* construction = *a;
-        if ( constructions.find(construction) != constructions.end() )
+        bool b = constructions.find(construction->pos) != constructions.end();
+        constructions[construction->pos] = *construction;
+        if ( b )
             continue;
+        //construction created
         for ( auto b = copy.begin(); b != copy.end(); b++ ) {
             EventHandler handle = (*b).second;
             handle.eventHandler(out, (void*)construction);
         }
     }
-    
-    constructions.clear();
-    constructions.insert(constructionsNow.begin(), constructionsNow.end());
 }
 
 static void manageSyndromeEvent(color_ostream& out) {
diff --git a/plugins/devel/eventExample.cpp b/plugins/devel/eventExample.cpp
index 49cdac4f9..f6fa649b8 100644
--- a/plugins/devel/eventExample.cpp
+++ b/plugins/devel/eventExample.cpp
@@ -6,6 +6,8 @@
 #include "modules/EventManager.h"
 #include "DataDefs.h"
 
+#include "df/construction.h"
+#include "df/coord.h"
 #include "df/item.h"
 #include "df/job.h"
 #include "df/world.h"
@@ -105,6 +107,14 @@ void building(color_ostream& out, void* ptr) {
 
 void construction(color_ostream& out, void* ptr) {
     out.print("Construction created/destroyed: 0x%X\n", ptr);
+    df::construction* constr = (df::construction*)ptr;
+    df::coord pos = constr->pos;
+    out.print("  (%d,%d,%d)\n", pos.x, pos.y, pos.z);
+    if ( df::construction::find(pos) == NULL )
+        out.print("  construction destroyed\n");
+    else
+        out.print("  construction created\n");
+    
 }
 
 void syndrome(color_ostream& out, void* ptr) {