diff --git a/file/lib/system/cache/builder/ChatPermissionCacheBuilder.class.php b/file/lib/system/cache/builder/ChatPermissionCacheBuilder.class.php
new file mode 100644
index 0000000..947b05b
--- /dev/null
+++ b/file/lib/system/cache/builder/ChatPermissionCacheBuilder.class.php
@@ -0,0 +1,44 @@
+<?php
+namespace wcf\system\cache\builder;
+use wcf\system\WCF;
+
+/**
+ * Caches the chat permissions for a combination of user groups.
+ * 
+ * @author 	Tim Düsterhus, Marcel Werk
+ * @copyright	2010-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	timwolla.wcf.chat
+ * @subpackage	system.cache.builder
+ */
+class ChatPermissionCacheBuilder implements ICacheBuilder {
+	/**
+	 * @see wcf\system\cache\ICacheBuilder::getData()
+	 */
+	public function getData(array $cacheResource) {
+		$data = array();
+		list(, $groupIDsStr) = explode('-', $cacheResource['cache']);
+		$groupIDs = explode(',', $groupIDsStr);
+		
+		if (count($groupIDs)) {
+			$conditionBuilder = new \wcf\system\database\util\PreparedStatementConditionBuilder();
+			$conditionBuilder->add('acl_option.packageID IN (?)', array(\wcf\system\package\PackageDependencyHandler::getDependencies()));
+			$conditionBuilder->add('acl_option.objectTypeID = ?', array(\wcf\system\acl\ACLHandler::getInstance()->getObjectTypeID('timwolla.wcf.chat.room')));
+			$conditionBuilder->add('option_to_group.optionID = acl_option.optionID');
+			$conditionBuilder->add('option_to_group.groupID IN (?)', array($groupIDs));
+			$sql = "SELECT		option_to_group.groupID, option_to_group.objectID AS roomID, option_to_group.optionValue,
+						acl_option.optionName AS permission
+				FROM		wcf".WCF_N."_acl_option acl_option,
+						wcf".WCF_N."_acl_option_to_group option_to_group
+						".$conditionBuilder;
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute($conditionBuilder->getParameters());
+			while ($row = $statement->fetchArray()) {
+				if (!isset($data[$row['roomID']][$row['permission']])) $data[$row['roomID']][$row['permission']] = $row['optionValue'];
+				else $data[$row['roomID']][$row['permission']] = $row['optionValue'] || $data[$row['roomID']][$row['permission']];
+			}
+		}
+		
+		return $data;
+	}
+}
\ No newline at end of file