diff --git a/__tests__/src/actions/window.test.js b/__tests__/src/actions/window.test.js
index 5f1dd790ae..ba0e755427 100644
--- a/__tests__/src/actions/window.test.js
+++ b/__tests__/src/actions/window.test.js
@@ -86,6 +86,7 @@ describe('window actions', () => {
           collectionIndex: 0,
           height: 400,
           id: 'helloworld',
+          layoutOrder: 3,
           manifestId: null,
           maximized: false,
           rangeId: null,
diff --git a/__tests__/src/components/WorkspaceMosaic.test.js b/__tests__/src/components/WorkspaceMosaic.test.js
index e89f5aa6f9..ed15fe9f8a 100644
--- a/__tests__/src/components/WorkspaceMosaic.test.js
+++ b/__tests__/src/components/WorkspaceMosaic.test.js
@@ -76,7 +76,11 @@ describe('WorkspaceMosaic', () => {
       });
     });
     it('by default use workspace.layout', () => {
-      wrapper = createWrapper({ windows: {}, workspace: { layout: 'foo' } });
+      wrapper = createWrapper({ windows: { foo: 'bar' }, workspace: { layout: 'foo' } });
+      expect(wrapper.instance().determineWorkspaceLayout()).toEqual('foo');
+    });
+    it('generates a new layout if windows do not match current layout', () => {
+      wrapper = createWrapper({ windows: { foo: 'bar' }, workspace: { layout: { first: 'foo', second: 'bark' } } });
       expect(wrapper.instance().determineWorkspaceLayout()).toEqual('foo');
     });
     it('when window ids match workspace layout', () => {
diff --git a/__tests__/src/lib/MosaicLayout.test.js b/__tests__/src/lib/MosaicLayout.test.js
new file mode 100644
index 0000000000..a364e77393
--- /dev/null
+++ b/__tests__/src/lib/MosaicLayout.test.js
@@ -0,0 +1,51 @@
+import MosaicLayout from '../../../src/lib/MosaicLayout';
+
+describe('MosaicLayout', () => {
+  describe('constructor', () => {
+    it('sets layout', () => {
+      expect(new MosaicLayout('foo').layout).toEqual('foo');
+    });
+  });
+  describe('addWindows', () => {
+    let instance;
+    beforeEach(() => {
+      instance = new MosaicLayout('foo');
+    });
+    it('case 1 window: adds to the top right', () => {
+      expect(instance.layout).toEqual('foo');
+      instance.addWindows(['bar']);
+      expect(instance.layout).toEqual({
+        direction: 'row',
+        first: 'foo',
+        second: 'bar',
+      });
+    });
+    it('case 3 windows: adds to the top right', () => {
+      expect(instance.layout).toEqual('foo');
+      instance.addWindows(['bar', 'bat', 'bark']);
+      expect(instance.layout).toEqual({
+        direction: 'row',
+        first: 'foo',
+        second: {
+          direction: 'column',
+          first: {
+            direction: 'row',
+            first: 'bat',
+            second: 'bark',
+          },
+          second: 'bar',
+        },
+      });
+    });
+  });
+  describe('removeWindows', () => {
+    let instance;
+    beforeEach(() => {
+      instance = new MosaicLayout({ first: 'foo', second: 'bar' });
+    });
+    it('case 1 window: returns a single window', () => {
+      instance.removeWindows(['bar'], { bar: ['second'] });
+      expect(instance.layout).toEqual('foo');
+    });
+  });
+});
diff --git a/src/components/WorkspaceMosaic.js b/src/components/WorkspaceMosaic.js
index db11272d89..db403ad5be 100644
--- a/src/components/WorkspaceMosaic.js
+++ b/src/components/WorkspaceMosaic.js
@@ -3,11 +3,12 @@ import PropTypes from 'prop-types';
 import {
   Mosaic, MosaicWindow, getLeaves, createBalancedTreeFromLeaves,
 } from 'react-mosaic-component';
-import { createRemoveUpdate, updateTree } from 'react-mosaic-component/lib/util/mosaicUpdates';
 import 'react-mosaic-component/react-mosaic-component.css';
 import difference from 'lodash/difference';
+import toPairs from 'lodash/toPairs';
 import MosaicRenderPreview from '../containers/MosaicRenderPreview';
 import Window from '../containers/Window';
+import MosaicLayout from '../lib/MosaicLayout';
 
 /**
  * Represents a work area that contains any number of windows
@@ -48,14 +49,10 @@ export class WorkspaceMosaic extends React.Component {
         return;
       }
 
-      // Generate a set of "removeUpdates" to update layout binary tree
       const removedWindows = difference(prevWindows, currentWindows);
-      const removeUpdates = removedWindows
-        .map(windowId => (
-          createRemoveUpdate(workspace.layout, this.windowPaths[windowId])
-        ));
-      const newTree = updateTree(workspace.layout, removeUpdates);
-      updateWorkspaceMosaicLayout(newTree);
+      const layout = new MosaicLayout(workspace.layout);
+      layout.removeWindows(removedWindows, this.windowPaths);
+      updateWorkspaceMosaicLayout(layout.layout);
     }
     // Handles when Windows are added (not via Add Resource UI)
     // TODO: If a window is added, add it in a better way #2380
@@ -76,22 +73,29 @@ export class WorkspaceMosaic extends React.Component {
 
   /**
    * Used to determine whether or not a "new" layout should be autogenerated.
-   * TODO: If a window is added, add it in a better way #2380
    */
   determineWorkspaceLayout() {
     const { windows, workspace } = this.props;
-    const windowKeys = Object.keys(windows).sort();
+    const sortedWindows = toPairs(windows)
+      .sort((a, b) => a.layoutOrder - b.layoutOrder).map(val => val[0]);
     const leaveKeys = getLeaves(workspace.layout);
     // Windows were added
-    if (!windowKeys.every(e => leaveKeys.includes(e))) {
+    if (!sortedWindows.every(e => leaveKeys.includes(e))) {
       // No current layout, so just generate a new one
-      if (leaveKeys.length === 0) {
-        return createBalancedTreeFromLeaves(windowKeys);
+      if (leaveKeys.length < 2) {
+        return createBalancedTreeFromLeaves(sortedWindows);
       }
-      // TODO: Here is where we will determine where to add a new Window #2380
-      return createBalancedTreeFromLeaves(windowKeys);
+      // Add new windows to layout
+      const addedWindows = difference(sortedWindows, leaveKeys);
+      const layout = new MosaicLayout(workspace.layout);
+      layout.addWindows(addedWindows);
+      return layout.layout;
+    }
+    // Windows were removed (perhaps in a different Workspace). We don't have a
+    // way to reconfigure.. so we have to random generate
+    if (!leaveKeys.every(e => sortedWindows.includes(e))) {
+      return createBalancedTreeFromLeaves(sortedWindows);
     }
-
     return workspace.layout;
   }
 
diff --git a/src/lib/MosaicLayout.js b/src/lib/MosaicLayout.js
new file mode 100644
index 0000000000..c64710a7c3
--- /dev/null
+++ b/src/lib/MosaicLayout.js
@@ -0,0 +1,79 @@
+import { createRemoveUpdate, updateTree } from 'react-mosaic-component/lib/util/mosaicUpdates';
+import {
+  getNodeAtPath, getOtherDirection, getPathToCorner, Corner,
+} from 'react-mosaic-component/lib/util/mosaicUtilities';
+import dropRight from 'lodash/dropRight';
+
+/** */
+export default class MosaicLayout {
+  /** */
+  constructor(layout) {
+    this.layout = layout;
+  }
+
+  /** */
+  pathToCorner(corner = Corner.TOP_RIGHT) {
+    return getPathToCorner(this.layout, corner);
+  }
+
+  /** */
+  pathToParent(path) {
+    return getNodeAtPath(this.layout, dropRight(path));
+  }
+
+  /** */
+  nodeAtPath(path) {
+    return getNodeAtPath(this.layout, path);
+  }
+
+  /**
+   * addWindows - updates the layout with new windows using an algorithm ported
+   * from the react-mosaic-components examples. Will always add to the Top Right
+   * https://github.com/nomcopter/react-mosaic/blob/5081df8d1528d4c3b83a72763a46a30b3048fe95/demo/ExampleApp.tsx#L119-L154
+   * @param {Array} addedWindowIds [description]
+   */
+  addWindows(addedWindowIds) {
+    addedWindowIds.forEach((windowId, i) => {
+      const path = this.pathToCorner();
+      const parent = this.pathToParent(path);
+      const destination = this.nodeAtPath(path);
+      const direction = parent ? getOtherDirection(parent.direction) : 'row';
+      let first;
+      let second;
+      if (direction === 'row') {
+        first = destination;
+        second = addedWindowIds[i];
+      } else {
+        first = addedWindowIds[i];
+        second = destination;
+      }
+      const update = {
+        path,
+        spec: {
+          $set: {
+            direction,
+            first,
+            second,
+          },
+        },
+      };
+      // We cannot batch the updates together because we need to recalculate
+      // the new location for each new window
+      this.layout = updateTree(this.layout, [update]);
+    });
+  }
+
+  /**
+   * removeWindows - Generate a set of "removeUpdates" to update layout binary
+   * tree. Then update the layout.
+   * @param  {Array} removedWindowIds
+   * @param  {Object} windowPaths - a lookup table for window paths
+   */
+  removeWindows(removedWindowIds, windowPaths) {
+    const removeUpdates = removedWindowIds
+      .map(windowId => (
+        createRemoveUpdate(this.layout, windowPaths[windowId])
+      ));
+    this.layout = updateTree(this.layout, removeUpdates);
+  }
+}
diff --git a/src/state/actions/window.js b/src/state/actions/window.js
index b48a5b78b8..b9af390403 100644
--- a/src/state/actions/window.js
+++ b/src/state/actions/window.js
@@ -52,6 +52,7 @@ export function addWindow(options) {
       displayAllAnnotations: config.displayAllAnnotations || false,
       height: 400,
       id: `window-${uuid()}`,
+      layoutOrder: numWindows + 1,
       manifestId: null,
       maximized: false,
       rangeId: null,