diff --git a/client/index.js b/client/index.js
index ef6d1a5cb6..887380d1ee 100644
--- a/client/index.js
+++ b/client/index.js
@@ -19,7 +19,7 @@ import {
   saveToColdStorage
 } from './cold-reload';
 
-Rx.config.longStackSupport = !!debug.enabled;
+const isDev = Rx.config.longStackSupport = !!debug.enabled;
 
 const log = debug('fcc:client');
 const hotReloadTimeout = 5000;
@@ -39,6 +39,7 @@ const devTools = window.devToolsExtension ? window.devToolsExtension() : f => f;
 const shouldRouterListenForReplays = !!window.devToolsExtension;
 
 const sagaOptions = {
+  isDev,
   window,
   document: window.document,
   location: window.location
diff --git a/client/sagas/index.js b/client/sagas/index.js
index 3a7fee2345..2c7e2781b7 100644
--- a/client/sagas/index.js
+++ b/client/sagas/index.js
@@ -2,5 +2,12 @@ import errSaga from './err-saga';
 import titleSaga from './title-saga';
 import localStorageSaga from './local-storage-saga';
 import hardGoToSaga from './hard-go-to-saga';
+import windowSaga from './window-saga';
 
-export default [ errSaga, titleSaga, localStorageSaga, hardGoToSaga ];
+export default [
+  errSaga,
+  titleSaga,
+  localStorageSaga,
+  hardGoToSaga,
+  windowSaga
+];
diff --git a/client/sagas/window-saga.js b/client/sagas/window-saga.js
new file mode 100644
index 0000000000..add0d4102c
--- /dev/null
+++ b/client/sagas/window-saga.js
@@ -0,0 +1,34 @@
+import { Observable } from 'rx';
+import { initWindowHeight } from '../../common/app/redux/types';
+import { updateWindowHeight } from '../../common/app/redux/actions';
+
+function getWindowSize(document, window) {
+  const body = document.getElementsByTagName('body')[0];
+  return window.innerHeight ||
+    document.docElement.clientHeight ||
+    body.clientHeight ||
+    0;
+}
+
+function listenForResize(document, window) {
+  return Observable.fromEvent(window, 'resize')
+    .debounce(250)
+    .startWith({})
+    .map(() => getWindowSize(document, window));
+}
+
+export default function windowSaga(
+  action$,
+  getState,
+  { isDev, document, window }
+) {
+  return action$
+    .filter(({ type }) => type === initWindowHeight)
+    .flatMap(() => {
+      if (isDev) {
+        return listenForResize(document, window);
+      }
+      return Observable.just(getWindowSize(document, window));
+    })
+    .map(updateWindowHeight);
+}
diff --git a/common/app/App.jsx b/common/app/App.jsx
index d2984be6b2..9e1be2fc7d 100644
--- a/common/app/App.jsx
+++ b/common/app/App.jsx
@@ -8,10 +8,9 @@ import { createSelector } from 'reselect';
 
 import {
   fetchUser,
-  updateWindowHeight,
+  initWindowHeight,
   updateNavHeight
 } from './redux/actions';
-import getWindowHeight from './utils/get-window-height';
 
 import Nav from './components/Nav';
 
@@ -50,7 +49,7 @@ export class FreeCodeCamp extends React.Component {
     picture: PropTypes.string,
     toast: PropTypes.object,
     updateNavHeight: PropTypes.func,
-    updateWindowHeight: PropTypes.func
+    initWindowHeight: PropTypes.func
   };
 
   componentWillReceiveProps({ toast: nextToast = {} }) {
@@ -68,7 +67,7 @@ export class FreeCodeCamp extends React.Component {
   }
 
   componentDidMount() {
-    this.props.updateWindowHeight(getWindowHeight());
+    this.props.initWindowHeight();
   }
 
   render() {
@@ -92,7 +91,7 @@ export class FreeCodeCamp extends React.Component {
 
 const wrapComponent = compose(
   // connect Component to Redux Store
-  connect(mapStateToProps, { updateWindowHeight, updateNavHeight, fetchUser }),
+  connect(mapStateToProps, { initWindowHeight, updateNavHeight, fetchUser }),
   // handles prefetching data
   contain(fetchContainerOptions)
 );
diff --git a/common/app/redux/actions.js b/common/app/redux/actions.js
index b89a2494af..7cdde164cd 100644
--- a/common/app/redux/actions.js
+++ b/common/app/redux/actions.js
@@ -32,6 +32,7 @@ export const updatePoints = createAction(types.updatePoints);
 // hardGoTo(path: String) => Action
 export const hardGoTo = createAction(types.hardGoTo);
 
+export const initWindowHeight = createAction(types.initWindowHeight);
 export const updateWindowHeight = createAction(types.updateWindowHeight);
 export const updateNavHeight = createAction(types.updateNavHeight);
 
diff --git a/common/app/redux/types.js b/common/app/redux/types.js
index 9860e941bc..068f7f7389 100644
--- a/common/app/redux/types.js
+++ b/common/app/redux/types.js
@@ -12,6 +12,7 @@ export default createTypes([
   // used to hit the server
   'hardGoTo',
 
+  'initWindowHeight',
   'updateWindowHeight',
   'updateNavHeight',
 
diff --git a/common/app/routes/challenges/components/Side-Panel.jsx b/common/app/routes/challenges/components/Side-Panel.jsx
index 1d93526c5a..80b9b98a27 100644
--- a/common/app/routes/challenges/components/Side-Panel.jsx
+++ b/common/app/routes/challenges/components/Side-Panel.jsx
@@ -12,7 +12,7 @@ import ToolPanel from './Tool-Panel.jsx';
 const mapStateToProps = createSelector(
   state => state.app.windowHeight,
   state => state.app.navHeight,
-  (windowHeight, navHeight) => ({ height: windowHeight - navHeight - 50 })
+  (windowHeight, navHeight) => ({ height: windowHeight - navHeight - 20 })
 );
 
 export class SidePanel extends PureComponent {
diff --git a/common/app/utils/get-window-height.js b/common/app/utils/get-window-height.js
deleted file mode 100644
index 08bb5e20bf..0000000000
--- a/common/app/utils/get-window-height.js
+++ /dev/null
@@ -1,18 +0,0 @@
-export default function getWindowHeight() {
-  try {
-    const win = typeof window !== 'undefined' ?
-      window :
-      null;
-    if (!win) {
-      return 0;
-    }
-    const docElement = win.document.documentElement;
-    const body = win.document.getElementsByTagName('body')[0];
-    return win.innerHeight ||
-      docElement.clientHeight ||
-      body.clientHeight ||
-      0;
-  } catch (e) {
-    return 0;
-  }
-}