More Arlington homeowners are discovering the benefits of adding an accessory dwelling unit (ADU) to their property. Whether it’s space for aging parents, adult children returning home, long-term guests, or rental income, ADUs offer a flexible way to make the most of your property.
In Arlington, detached units are typically limited to 560 square feet—roughly the size of a two-car garage. While the footprint is small, the versatility is massive.
Why consider an ADU?
1. Create a flexible living space
Need a home office, guest suite, or space for aging parents? An ADU can adapt to your family’s changing needs. For one Arlington homeowner, adding an ADU was a way to prepare for an elderly parent who might move in someday. Although the home already had a fully finished basement, the ADU offered something different: more privacy and a greater sense of having one’s own space.
2. Generate rental income while providing an affordable housing option
A well-designed ADU can provide a steady income stream, helping offset mortgage costs or fund future renovations. In a competitive Arlington rental market, it also offers an affordable housing option for others. However, to permit an ADU for rental purposes, the property owner must live in the house or the ADU.
3. Increase property value
Thoughtfully designed ADUs can significantly boost your home’s resale value. Buyers increasingly look for homes with versatile living options that fit modern lifestyles.
4. Preserve privacy and neighborhood character
ADUs can be designed to complement your existing property, maintaining privacy for both residents and neighbors. Garage-style units with living space above often blend naturally into Arlington neighborhoods while adding valuable living space.
Can anyone have an ADU?
Not every property can accommodate an ADU. Setbacks, lot size, and existing zoning all determine what’s possible:
- Interior lots: A one–and–a–half–story ADU must maintain at least 5 feet from rear and side yards; a full two-story unit requires at least 10 feet.
- Corner lots: The nearest wall must be at least 25 feet from the street.
- Proximity to existing structures: The ADU must be at least 8 feet from any above-grade structure connected to your house.
Reviewing your plat (survey) is one of the first steps in understanding the buildable area on your property. On a current project, the homeowners didn’t realize the setbacks would place the ADU near the middle of their yard. We helped them redesign it smaller so it could sit closer to the property line.
Older homes that predate current zoning regulations may require additional review if they don’t comply with current setback requirements. Planning early and understanding these constraints prevents delays later in the process.
What if you live in Falls Church?
Regulations differ between Falls Church City and Fairfax County.
- Falls Church City: Approved detached ADUs “by right” on most single-family lots; size, height, owner-occupancy, and short-term rental limits apply.
- Fairfax County: Refers to ADUs as Accessory Living Units (ALUs) and is much more restrictive on detached units.
The bottom line: Regulations differ between jurisdictions. Local knowledge matters.
Build Your ADU with Confidence
Navigating zoning rules, permits, design, and construction details requires experience — especially in Arlington, where lot conditions and long-established regulations can vary block by block.
At Alair, we provide transparent cost estimates, expert design guidance, and a clear process from concept through construction. Our goal is to help homeowners make informed decisions and enjoy a smooth building experience.
“The Alair team was wonderful during our major renovation. Our project manager always kept us apprised of the schedule and any changes. We added a garage with an ADU above it, a mudroom, an exercise room, a new kids’ bathroom upstairs, a large back deck, and gutted the kitchen. We love our new space and can’t thank them enough.” – Kat Cleland
If you’re considering an ADU, schedule a free consultation to explore what’s possible on your property and see how Alair can help you maximize your lot.
