Missing Middle Housing: Where We Are and Where We are Going

By Anne Bodine

On March 22, 2023, the County Board voted 5–0 to change Arlington’s Zoning Code and General Land Use Plan (GLUP) to allow “Missing Middle” (MM) or “Expanded Housing Options” for duplexes up to six-plexes on most lots in residential zones that until now have allowed only single-family construction (i.e., zones R-5, R-6, R-8, and R-20). This policy begins July 1, 2023 and changes our existing mixed (old and new, single- and multi-family) neighborhoods to multi-family new home neighborhoods. 

First, let’s look at our current housing stock. You might be surprised to learn that in terms of types of dwelling units, Lyon Park is diverse, with single-family homes less than one-third of our existing stock:

Single Family Detached Homes:  926

Apartments – Garden:  1,120

Apartments – Mid-rise:  502

Garden style condos: 175

Duplexes / Side-by-sides: 125 

Stacked condos: 120

Townhomes:  27

Total:  2,995

Now let’s discuss what the County Board decided on the new Missing Middle plan. Most of Lyon Park is zoned R-6; countywide, R-6 makes up 66% of the areas that were “rezoned.”  The county will now allow property owners in all rezoned areas to:

  • – build up to 6 units on lots “by-right” (i.e., no County Board review);
  • – build new MM or convert an existing single-family home into MM units, with an annual cap of 58 permits per year for 5 years, of which 30 may be in R-6;
  • – erect structures with the same setbacks and height restrictions as single-family homes, but with a 5% “bonus” lot coverage above single-family home projects;
  • – provide a minimum 0.5 parking spaces per unit if the home is 3/4–mile from a Metro station entrance (shown on the map below) or 1/2–mile from a stop on the Premium Transit Network along Columbia Pike, and provide at least 1 space per unit (the current standard) for other locations and for all lots on a cul-de-sac;  
  • – preserve or plant at least 4 shade trees on properties with new 2–4 unit buildings and at least 8 shade trees for 5- and 6-plexes;  
  • – cap maximum floor area within a range of 4,800 square feet for the smallest MM structure (a combined stacked duplex) up to 8,000 square feet for the largest (5- to 6-plexes);
  • – add interior accessory dwellings only for the side-by-side two- or three-unit semi-detached homes (e.g., a 3-unit townhome becomes a 6-plex if each townhome adds an accessory dwelling);
  • – provide zero onsite parking on streets (such as the 100 block of North Edgewood St.) that currently lack onsite parking, meaning that all parking in those blocks spills over to the street.