diff --git a/src/timeline/component/Group.js b/src/timeline/component/Group.js
index 46779a0f..7e78e5ee 100644
--- a/src/timeline/component/Group.js
+++ b/src/timeline/component/Group.js
@@ -24,10 +24,14 @@ function Group (contentPanel, labelPanel, groupId, options) {
     }
   };
 
+  this.dom = {};
+
   this.top = 0;
   this.left = 0;
   this.width = 0;
   this.height = 0;
+
+  this._create();
 }
 
 Group.prototype = new Component();
@@ -35,6 +39,53 @@ Group.prototype = new Component();
 // TODO: comment
 Group.prototype.setOptions = Component.prototype.setOptions;
 
+/**
+ * Create DOM elements for the group
+ * @private
+ */
+Group.prototype._create = function() {
+  var label = document.createElement('div');
+  label.className = 'vlabel';
+  this.dom.label = label;
+
+  var inner = document.createElement('div');
+  inner.className = 'inner';
+  label.appendChild(inner);
+  this.dom.inner = inner;
+};
+
+/**
+ * Get the HTML DOM label of this group
+ * @returns {Element} label
+ */
+Group.prototype.getLabel = function getLabel() {
+  return this.dom.label;
+};
+
+/**
+ * Set the group data for this group
+ * @param {Object} data   Group data, can contain properties content and className
+ */
+Group.prototype.setData = function setData(data) {
+  // update contents
+  var content = data && data.content;
+  if (content instanceof Element) {
+    this.dom.inner.appendChild(content);
+  }
+  else if (content != undefined) {
+    this.dom.inner.innerHTML = content;
+  }
+  else {
+    this.dom.inner.innerHTML = this.groupId;
+  }
+
+  // update className
+  var className = data && data.className;
+  if (className) {
+    util.addClassName(this.dom.label, className);
+  }
+};
+
 /**
  * Set item set for the group. The group will create a view on the itemSet,
  * filtered by the groups id.
@@ -111,21 +162,15 @@ Group.prototype.getSelection = function getSelection() {
 Group.prototype.repaint = function repaint() {
   var resized = this.itemSet.repaint();
 
+  // TODO: top is redundant, cleanup
   this.top    = this.itemSet ? this.itemSet.top : 0;
   this.height = this.itemSet ? this.itemSet.height : 0;
 
-  // TODO: reckon with the height of the group label
+  this.dom.label.style.height = this.height + 'px';
 
-  if (this.label) {
-    // TODO: only update the labels width/height when the label is changed
-    var inner = this.label.firstChild;
-    this.props.label.width = inner.clientWidth;
-    this.props.label.height = inner.clientHeight;
-  }
-  else {
-    this.props.label.width = 0;
-    this.props.label.height = 0;
-  }
+  // calculate inner size of the label
+  resized = util.updateProperty(this.props.label, 'width', this.dom.inner.clientWidth) || resized;
+  resized = util.updateProperty(this.props.label, 'height', this.dom.inner.clientHeight) || resized;
 
   return resized;
 };
diff --git a/src/timeline/component/GroupSet.js b/src/timeline/component/GroupSet.js
index d1981858..c720abc8 100644
--- a/src/timeline/component/GroupSet.js
+++ b/src/timeline/component/GroupSet.js
@@ -271,6 +271,8 @@ GroupSet.prototype.repaint = function repaint() {
               height: null
             });
 
+            // TODO: do not recreate the group with every update
+
             group = new Group(me.contentPanel, me.labelPanel, id, groupOptions);
             group.on('change', me.emit.bind(me, 'change')); // propagate change event
             group.setRange(me.range);
@@ -282,8 +284,8 @@ GroupSet.prototype.repaint = function repaint() {
             // as this call will already trigger a repaint
           }
 
-          // TODO: update group data
-          group.data = groupsData.get(id);
+          // update group data
+          group.setData(groupsData.get(id));
           break;
 
         case 'remove':
@@ -311,7 +313,7 @@ GroupSet.prototype.repaint = function repaint() {
     }
     for (i = 0; i < this.groupIds.length; i++) {
       id = this.groupIds[i];
-      label = this._createLabel(id);
+      label = this.groups[id].getLabel();
       labelSet.frame.appendChild(label);
     }
 
@@ -338,19 +340,10 @@ GroupSet.prototype.repaint = function repaint() {
   for (id in groups) {
     if (groups.hasOwnProperty(id)) {
       group = groups[id];
-      label = group.label;
-      if (label) {
-        label.style.height = group.height + 'px';
-
-        console.log('label height groupId=', id, ' height', group.height)
-
-        var width = label.firstChild && label.firstChild.clientWidth || 0;
-        maxWidth = Math.max(maxWidth, width);
-      }
+      maxWidth = Math.max(maxWidth, group.props.label.width);
     }
   }
-  if (this.props.labels.width != maxWidth) resized = true;
-  this.props.labels.width = maxWidth;
+  resized = util.updateProperty(this.props.labels, 'width', maxWidth) || resized;
 
   // recalculate the height of the groupset
   var fixedHeight = (asSize(options.height) != null);
@@ -384,43 +377,9 @@ GroupSet.prototype.repaint = function repaint() {
   this.width = groupSet.offsetWidth;
   this.height = height;
 
-  console.log('groupset.repaint resized=', resized)
-
   return resized;
 };
 
-/**
- * Create a label for group with given id
- * @param {Number} id
- * @return {Element} label
- * @private
- */
-GroupSet.prototype._createLabel = function(id) {
-  var group = this.groups[id];
-  var label = document.createElement('div');
-  label.className = 'vlabel';
-  var inner = document.createElement('div');
-  inner.className = 'inner';
-  label.appendChild(inner);
-
-  var content = group.data && group.data.content;
-  if (content instanceof Element) {
-    inner.appendChild(content);
-  }
-  else if (content != undefined) {
-    inner.innerHTML = content;
-  }
-
-  var className = group.data && group.data.className;
-  if (className) {
-    util.addClassName(label, className);
-  }
-
-  group.label = label; // TODO: not so nice, parking labels in the group this way!!!
-
-  return label;
-};
-
 /**
  * Get the width of the group labels
  * @return {Number} width
diff --git a/src/util.js b/src/util.js
index 46bbb8b9..788cea5e 100644
--- a/src/util.js
+++ b/src/util.js
@@ -463,7 +463,7 @@ util.toArray = function toArray(object) {
  * @param {*} value
  * @return {Boolean} changed
  */
-util.updateProperty = function updateProp (object, key, value) {
+util.updateProperty = function updateProperty (object, key, value) {
   if (object[key] !== value) {
     object[key] = value;
     return true;