diff --git a/addons/web/static/src/js/core.js b/addons/web/static/src/js/core.js
index c64da7e5810..29f6c3e4d9e 100644
--- a/addons/web/static/src/js/core.js
+++ b/addons/web/static/src/js/core.js
@@ -345,31 +345,16 @@ instance.web.Session.include( /** @lends instance.web.Session# */{
     load_css: function (files) {
         var self = this;
         _.each(files, function (file) {
-            $('head').append($('<link>', {
-                'href': self.url(file, null),
-                'rel': 'stylesheet',
-                'type': 'text/css'
-            }));
+            openerp.loadCSS(self.url(file, null));
         });
     },
     load_js: function(files) {
         var self = this;
         var d = $.Deferred();
-        if(files.length !== 0) {
+        if (files.length !== 0) {
             var file = files.shift();
-            var tag = document.createElement('script');
-            tag.type = 'text/javascript';
-            tag.src = self.url(file, null);
-            tag.onload = tag.onreadystatechange = function() {
-                if ( (tag.readyState && tag.readyState != "loaded" && tag.readyState != "complete") || tag.onload_done )
-                    return;
-                tag.onload_done = true;
-                self.load_js(files).done(function () {
-                    d.resolve();
-                });
-            };
-            var head = document.head || document.getElementsByTagName('head')[0];
-            head.appendChild(tag);
+            var url = self.url(file, null);
+            openerp.loadJS(url).done(d.resolve);
         } else {
             d.resolve();
         }
diff --git a/addons/web/static/src/js/openerpframework.js b/addons/web/static/src/js/openerpframework.js
index 5dcc2197944..f190fefeba3 100644
--- a/addons/web/static/src/js/openerpframework.js
+++ b/addons/web/static/src/js/openerpframework.js
@@ -933,6 +933,46 @@ openerp.jsonpRpc = function(url, fct_name, params, settings) {
     });
 };
 
+openerp.loadCSS = function (url) {
+    if (!$('link[href="' + url + '"]').length) {
+        $('head').append($('<link>', {
+            'href': url,
+            'rel': 'stylesheet',
+            'type': 'text/css'
+        }));
+    }
+};
+openerp.loadJS = function (url) {
+    var def = $.Deferred();
+    if ($('script[src="' + url + '"]').length) {
+        def.resolve();
+    } else {
+        var script = document.createElement('script');
+        script.type = 'text/javascript';
+        script.src = url;
+        script.onload = script.onreadystatechange = function() {
+            if ((script.readyState && script.readyState != "loaded" && script.readyState != "complete") || script.onload_done) {
+                return;
+            }
+            script.onload_done = true;
+            def.resolve(url);
+        };
+        script.onerror = function () {
+            console.error("Error loading file", script.src);
+            def.reject(url);
+        };
+        var head = document.head || document.getElementsByTagName('head')[0];
+        head.appendChild(script);
+    }
+    return def;
+};
+openerp.loadBundle = function (name) {
+    return $.when(
+        openerp.loadCSS('/web/css/' + name),
+        openerp.loadJS('/web/js/' + name)
+    );
+};
+
 var realSetTimeout = function(fct, millis) {
     var finished = new Date().getTime() + millis;
     var wait = function() {