I see on page 4-15 of the zoning document you forwared that for the zoning E-TU-C mentioned, that a duplex is alright, as is an accessory dwelling unit.

Two 14x70' lots will make for two nice single-family row homes.For the CMX2.5, ammenities to an apartment building are considered accessory spaces and still classified the same as the apartment itself (residential).

Update: it looks like Fairfax County is removing the age and disability requirement for accessory living units (previously known as accessory dwelling units).

I am in the process of getting a HELOC on my home and an appraiser is giving me a hard time about the kitchen located in the accessory apartment.

An accessory dwelling unit is "accessory" to a main dwelling.  

And the proposed plan below will start the middle of June.Cap STR registration certificates town-wide at the 1255.Phase out STRs in both multi-family units and Accessory Dwelling Units.

For a cost-effective accessory dwelling unit (ADU) in Tucson, Arizona, consider prefab ADUs, which are quick and affordable, with prices ranging from $50,000 to $200,000.

I want to get permits to turn the added units into an ADU (accessory dwelling unit).

On SF-3 we're limited to 2 dwelling units per lot.There are two main ways that we get 2 dwelling units on a lot - a duplex or a house with an Accessory Unit (garage apartment, granny flat, etc).

It is a 3/2 upstairs and a first floor accessory unit that is a 2/1.