Virtual Fairfax


  • The Installation Guide provides information about installing the required TerraExplorer plug-in.
  • The Getting Started with Virtual Fairfax document is an abridged quick start guide designed to enable new users to swiftly start their exploration in Virtual Fairfax.
  • The full documentation provides a comprehensive guide that fully explains the navigation, search, data, tools, and many other aspects of Virtual Fairfax.
  • A list of Frequently Asked Questions (FAQs) have been placed at the bottom of this page. If a question you have is not answered by this list, please see the contact information section about sending an email.

System Requirements

3-D viewing of buildings and terrain places heavy demands on users’ computers since much of the rendering occurs on the user’s (client) computer. As a result, Virtual Fairfax has some recommended system and connection standards to ensure a positive exploring experience. Some older or low-end computers, slow internet connections, and certain software configurations may create difficulties in using the application. There are now two versions of the required TerraExplorer Viewer plug-in that are being supported in Virtual Fairfax - 5.13 and 6.1. The system requirements are significantly different for each version.

TerraExplorer Viewer 5.13 System Requirements

  • Operating System - Windows 98/2000/Me/XP/Vista/7 (other operating systems such as Macintosh are not supported)
  • System Memory - 512MB RAM (1024MB or more recommended)
  • Video Card - 64MB of memory (128MB or more recommended)
  • Internet Connection - Broadband connection recommended.
  • Browser - Microsoft Internet Explorer 6 or higher should be installed on machine. Virtual Fairfax can run on more recent versions of FireFox, Opera, or Safari, but it calls Internet Explorer from within the browser window.

TerraExplorer Viewer 6.1 System Requirements

  • Operating System - Windows XP/Vista/7
  • System Memory - 1GB RAM (4GB or more recommended)
  • Video Card - 128MB of memory (512MB or more recommended). A video card with pixel shared v3.0 and vertex shader v3.0 is required for the display of dynamic water effects, animated cloud map, and sky texture
  • Internet Connection - Broadband connection recommended.
  • Browser - Microsoft Internet Explorer 7 or higher should be installed on machine. Virtual Fairfax can run on more recent versions of FireFox, Opera, or Safari, but it calls Internet Explorer from within the browser window.

Data Disclaimer

The geographic data contained in Virtual Fairfax is NOT to be construed or used as a “legal description”.  Virtual Fairfax does not contain survey data.  Any determination of topography or contours, or any depiction of physical improvements, property lines or boundaries is for general information only and shall not be used for the design, modification, or construction of improvements to real property or for flood plain determination.  While Fairfax County strives to provide the best data possible, it does not provide any guarantee of accuracy or completeness regarding the map information.  Any errors or omissions should be reported to the Fairfax County Geographic Information Systems and Mapping Services Branch of the Department of Information Technology.  In no event will Fairfax County be liable for any damages, including but not limited to loss of data, lost profits, business interruption, loss of business information or any other pecuniary loss that might arise from the use of this application or information it contains.

Contact Information

Questions about Virtual Fairfax may be sent to The developers of Virtual Fairfax are also interested in hearing ideas for new features and changes in future versions of the application.

Frequently Asked Questions (FAQs) (click on a question to see the answer)

System Requirements

Your computer or network security settings may prevent you from installing the plug-in. You may need to use an administrator login to complete the installation.  Additionally, this plug-in is only designed to work on MS Windows operating systems (XP, Vista, 7) and may not install in other operating systems.

Yes, as long as the license is valid and recognized.

The TerraExplorer plug-in that is required to use Virtual Fairfax only allows one use at a time.  If you are running Virtual Fairfax in your web browser, you cannot open another session of Virtual Fairfax (or any other application using the TerraExplorer plug-in).

The TerraExplorer plug-in that is necessary to run Virtual Fairfax is not currently available for these other operating systems.  Future updates to TerraExplorer may change this condition.


The aerial imagery was captured in spring of 2009, but is not scheduled to be updated until 2013.  The 3-D models were captured from 2007 and 2009 imagery and will be updated with additional buildings as funding and needs arise. The 2-D layers of address points, parcels, and roads are updated at least bi-monthly.

The building wireframes and textured imagery on their facades were created from oblique (taken at an angle) aerial imagery captured in 2007 and 2009 by the Pictometry corporation.  With many overlapping images of buildings from multiple angles, computer algorithms were able to construct accurate models of the buildings in 3-D using processes similar to triangulation.  Images from the aerial imagery are then wrapped around the wireframes.  Technicians further refine the buildings to add details and ensure integrity.

The creation of detailed 3-D building models is an expensive and time-consuming process.  Fairfax County has focused its limited resources on commercial areas that are likely to experience significant commercial development and a few other areas of interest.

When navigating near the horizon, it is possible that the elevation of the ground level and the 3-D building elevation don’t agree.  This creates the appearance of "floating" buildings.  Further refining of the terrain and building models should minimize this effect in the future.

There may have been some errors during the 3-D building creation process.  Future updates to the buildings layer should fix many of these issues.

The ground imagery was captured from an airplane in spring of 2009.


You may search for any valid Fairfax County address, FCPS school, Fairfax County Park, and a variety of other types of locations like cemeteries, churches, post offices, shopping centers, etc.  Please note that no searchable data type is deemed exhaustive—there are likely locations that exist in the County that cannot be found through the search function.

If you do not receive results from a search query, please read the suggestions provided in the Search Results box.  There are a variety of reasons for an unsuccessful search:

  1. A wrong spelling
  2. The searched address may not be in Fairfax County
  3. A city, state, or ZIP code was added to an address search
  4. A park search did not include the keywords "park", "RecCenter", or "golf course"
  5. A school search did not include the keywords "school", "es", "ms", "hs", "elementary", "middle" , or "high"
  6. Sometimes school names are shortened in our database so that "Whitman MS" will be found while "Walt Whitman MS" may not
  7. Missing or wrong data in the application

Using Virtual Fairfax

The User Guide document is a comprehensive help document that thoroughly explains all aspects of the Virtual Fairfax application.  For a briefer introduction to Virtual Fairfax, the Quick Start guide is also available.

Make sure that you are in an area of the County that has 3-D buildings.  Because of the time required to download and render the very rich 3-D data, it may take a few moments for the buildings to appear.  It may also help to move the map a bit to force a redraw.   If you are still unable to see buildings, it may be because:

  1. Your computer and/or network connection may not be of sufficient specifications to properly render the 3-D buildings.
  2. A firewall or other security setting on your computer or network may be preventing the download of the building models.
  3. A communication problem between servers or over the network may prevent buildings from downloading.

This error message is indicating that a specific 3-D building was not able to be loaded for a particular view.  If you ever see this message during a Virtual Fairfax session, it is recommended that you hit the "Ignore All" button to prevent error messages from reappearing.

The 3-D building models are very rich in data that must be downloaded from the internet and rendered on your computer.  This requires significant network and video processing resources, and some computers may strain under this load, causing slow performance.

Ensure that the desired layer is turned on ("checked") in the left-hand blue panel.  It is also possible that you are zoomed too far away from the data features; try zooming a bit closer (within a few kilometers) to see if the layer draws.  2-D layers may take a bit of time to download and draw.   If you still do not see the layer after waiting, you may also try to navigate or zoom slightly to force the layer to draw.

Refreshing the web page may fix this issue.  The problem, however, is likely due to a network communication problem that must be resolved before Virtual Fairfax will work properly.

To unfreeze the application you may hit the refresh button on your browser, or failing that, restart the web browser and navigate back to Virtual Fairfax.

Yes.  Click the "edit drawing" icon next to the drawing name under the "User Layers and Graphics" section of the left-hand blue panel.  While properties of the drawing may be updated, its location and shape may not be changed.

The 3-D buildings layer may obscure address point icons.  If you are unable to click the address point in an area where 3-D buildings exist, temporarily turn off the 3-D building layer by unchecking the box next to it in the left-hand blue panel.

This movement, "throwing", is a feature of navigating in Virtual Fairfax.  If you wish to stop this motion, you may click the "Stop Flight" link on the top of the map window.  You may also right click on the map and select "Stop".

For full documentation on these applications, you may visit their sites: My Neighborhood, Real Estate Assessment Information Site (iCare), & LDSNet.

If I have a suggestion for an improvement to Virtual Fairfax, where should I send it?

Please send all comments and questions to

Virtual Fairfax Welcome Page