The Arlington County Zoning Ordinance (ACZO) does not expressly provide for whether bay windows or “bump outs” may encroach into required yard setbacks.
Relevant ACZO Citations
- Article 3. Density and Dimensional Standards §3.1.1.B Gross Floor Area
- Article 3. Density and Dimensional Standards §3.1.3.C Footprint, main building
- Article 3. Density and Dimensional Standards §3.2.6.A.3(a)(1) Encroachments allowed into required yards and courts
- Article 18. Definitions §18.2 General Terms defined
Bay windows containing any livable space (floor area) may not encroach into required setbacks. Bump outs are not permitted to encroach.
Bay windows are generally defined as follows: a window or series of windows projecting from the outer wall of a building and forming a bay in a room and a projection outward from the main wall.
ACZO §3.1.1.B defined gross floor area as the sum of the area of the horizontal surface of the several floors of a building measured from the exterior faces of exterior walls, to include all floor area not defined as gross parking area.
ACZO §3.1.3.C states inter alia, that the main building footprint shall include all parts of a main building that rest, directly or indirectly, on the ground, including, by way of illustration and not by limitation, attached garages, bay or oriel windows with floor space.
ACZO §3.2.6.A.3(a)(1) states bay and oriel windows without floor space and chimneys may encroach 18 inches into required yards and courts.
Accordingly, any bay or oriel windows which include floor space shall not be permitted to encroach into required yard setbacks. A bay window may have a separate roof or may be covered by the main roof.
“Bump Outs” which are walls which project from the main wall of the dwelling will not be treated as a bay windows. Accordingly, no encroachment into the required yard setbacks is permitted.
“Box Bay” windows may be permitted so long as the proposed feature is at least fifty-one percent (51%) window area.
There will be no restriction against bay windows that meet the required standards for encroachment that are located on upper floors of the house.