Arlington Detached ADU: A Completely Independent Living Space on Your Own Property

A detached ADU is a fully independent residential structure built on the same lot as the primary home but physically separate from it. In Arlington, detached ADUs are permitted subject to setback, lot coverage, height, and size requirements under the County's ADU ordinance.

Detached ADUs in Arlington typically range from $220,000 to $450,000+ depending on size, finish level, and site conditions. Utility connection costs (new electrical service, water, sewer) are a significant variable. Use our Pricing Guide for current ranges.

Arlington County requires detached ADUs to maintain minimum setbacks from rear and side property lines — typically 5–10 feet depending on zoning district. The specific setback requirements for your lot depend on your zoning classification. Berriz Design Build conducts a property-specific analysis before design begins.

Yes. Detached ADUs can have independent utility connections (electrical, water, sewer) or share connections with the primary home. Independent connections provide more flexibility for rental use but add cost. Berriz Design Build evaluates the best utility configuration for your specific project.

From initial consultation to final certificate of occupancy, most detached ADU projects take 10–16 months. Permitting typically takes 6–14 weeks. Berriz Design Build's integrated design-build model compresses the overall timeline.

36+ years of Arlington ADU experience, in-house design and construction, and a thorough approach to the site, zoning, utility, and architectural challenges that determine whether a detached ADU becomes a property asset or a construction headache.