Understanding Alexandria’s Floor-to-Area Ratio Requlations

Alexandria Zoning – Know your FAR before you design


Floor-to-area ratio (FAR) is a term applied to the measurement of the aggregate area of the floor of a building divided by the area of the lot that a building is sited on. In Alexandria, any addition to a home must comply with the FAR requirements for the property. You can check out the FAR requirements for your home using this City of Alexandria Zoning map


Why Should I Know my Specific FAR Regulations?

The Alexandria Zoning Ordinance specifies FAR for different zoning districts, and exceeding these limits can result in the denial of building permits and other issues. 

If you know your FAR and how much area is available to work with, you can make informed decisions about how much house can be built on a property.

Alexandria has FAR regulations to uphold and maintain the architectural character and aesthetic harmony of neighborhoods, by controlling building density and bulk.

Check out our blog post to learn more about the process behind renovating historic Alexandria buildings here.


How Do I Find My Zone?

You can use the interactive map found on the City of Alexandria’s government website called “Parcel Viewer” to identify specific zoning regulations for any Alexandria address. The map is very accessible and easy to use. You can input your address or parcel ID into the search bar, and it will give you information regarding your specific zoning code and details.


 Why Does My Zone Code Matter?

In relation to FAR, your zone code determines the measurement threshold for how much space you are legally allowed to utilize. This information can be found within the Alexandria Zoning Ordinance documents. We have compiled most of the relevant residential-dwelling codes and their associated FAR limitations in a list in order to streamline this system for homeowners interested in a remodeling project:

(Zone: Maximum FAR permittance)

Single Family Dwelling Zones (low-density residential neighborhoods)
  • R-20: 0.25
  • R-12: 0.30
  • R-8: 0.35
  • R-5: 0.45


Single/ 2 Family Zones
  • R-2-5: 0.45


Townhouse and Multifamily Zones
  • RA (multifamily): 0.6
  • RB (townhouse zone): 0.75
  • RC (high-density apartment zone): 1.25
  • RM (townhouse zone): 1.5
  • RCX (medium-density apartment zone): 1.25
  • RD (high-density apartment zone): no FAR applies, other regulations in place
  • RT (townhouse zone): 0.5
  • RMF (residential multifamily zone): 0.75


Does all Floor Space Contribute to My Total Floor Area?

Determining the FAR allowance for a property is relatively straightforward, but knowing the city’s interpretation of how a building uses FAR is much less so. Basements, stairs, parts of attics and other spaces can be deducted from FAR calculations and allow for smaller or larger buildings depending on how these are interpreted.  

Exclusions can be tricky to navigate, as they vary from zone to zone. You can refer to this section of the Alexandria Zoning Ordinance to read about more specific exclusions that pertain to your zone. In most residential dwellings, here are a few general items to keep out of your measurements:

        Any attic space with a ceiling height less than seven (7) feet

        Stairs and elevators

        Floor space used specifically for mechanical/utility purposes

        Lavatories of which only a maximum of 50 square feet of each lavatory can be excluded


        Spaces under open balconies


        Porticos and porches with few exceptions

Floor area with a ceiling height fifteen (15) feet or greater shall be counted twice (2x), and floor area with a ceiling height twenty-five (25) feet or greater shall be counted three-times (3x).


Redfin can be a very helpful source to find a property’s square footage or public details regarding a property.


Alexandria Zoning Information:

(AlexandriaVA.Gov)​​ (library.municode)​​ (Alexandria Living Magazine)​ (FAR Calculator).

We love questions just as much as we love building stuff. Give us a call at 703-836-6010, email us at [email protected], or fill out a contact form if you are interested in working with us here.

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