# Arlington ADU Cost: What You'll Actually Pay — and Why the Range Is So Wide > Transparent ADU cost information for Arlington, VA. Design-build experience since 1994. Understand what drives ADU pricing and get accurate estimates. - **Source:** https://berrizdesign.com/services/adu/cost/ - **Company:** Berriz Design Build, LLC — Design-build home remodeling and landscape design contractor, founded 1994 - **Contact:** (703) 552-7565 · bob@berrizdesign.com - **Based in:** Arlington, VA - **Service:** ADU Cost - **Service area:** Arlington, VA, McLean, VA, Vienna, VA, Great Falls, VA, Oakton, VA, Alexandria, VA, Clifton, VA, Fairfax Station, VA ## Questions and answers **What is the average ADU cost in Arlington, VA?** ADU costs in Arlington typically range from $120,000 to $450,000+ depending on type and scope. Basement ADU conversions generally range from $120,000–$200,000. Attached additions range from $180,000–$320,000. Detached backyard cottages range from $220,000–$450,000+. Use our Pricing Guide for current ranges. **What are the biggest cost drivers for an ADU in Arlington?** The five primary cost drivers are: (1) ADU type (detached costs more than interior conversion), (2) size and finish level, (3) existing utility infrastructure (adding new service connections adds cost), (4) site conditions (slope, soil, access), and (5) permit and design fees. **Are there hidden costs in ADU construction in Arlington?** Common unexpected costs include utility connection upgrades, soil remediation, structural reinforcement for interior conversions, and permit revision cycles. Berriz Design Build conducts a thorough site evaluation before providing estimates to identify these factors upfront. **Does an ADU increase my Arlington property value?** Yes. A well-designed ADU in Arlington typically adds $150,000–$300,000 to property value depending on type and quality. Rental income potential also contributes to the investment case. Berriz Design Build designs ADUs with both livability and resale value in mind. **Can I finance an ADU in Arlington?** Yes. Common financing options include home equity loans, HELOCs, cash-out refinancing, and construction loans. Some lenders offer ADU-specific financing products. Berriz Design Build can connect you with lenders experienced in Northern Virginia ADU financing. **How do I get an accurate ADU cost estimate for my Arlington property?** The most accurate estimate requires a site visit and zoning analysis. Berriz Design Build conducts initial consultations to evaluate your lot, existing infrastructure, and goals before providing a detailed estimate. Use our Pricing Guide for current ranges, then connect with us for a property-specific assessment. ## Page content The Berriz Perspective The ADU cost ranges you find online — '$80,000 to $300,000' — are technically accurate and practically useless. In Arlington, the actual cost of your ADU depends on five specific factors that generic estimates never account for: your lot's zoning constraints, your existing utility infrastructure, your soil conditions, your chosen ADU type, and your finish level. Berriz Design Build has built ADUs across the full cost spectrum in Arlington. We've seen $140,000 basement conversions and $420,000 detached cottages, and we know exactly what drives the difference. The most expensive mistake you can make is choosing a contractor based on the lowest estimate — because the lowest estimate is almost always the one that doesn't account for what your specific project actually requires. We give you the real number upfront. Common Questions ## What Arlington Homeowners Ask About ADU Cost ### Discovery & Eligibility What is the average ADU cost in Arlington, VA? ADU costs in Arlington typically range from $120,000 to $450,000+ depending on type and scope. Basement ADU conversions generally range from $120,000–$200,000. Attached additions range from $180,000–$320,000. Detached backyard cottages range from $220,000–$450,000+. Use our Pricing Guide for current ranges. What are the biggest cost drivers for an ADU in Arlington? The five primary cost drivers are: (1) ADU type (detached costs more than interior conversion), (2) size and finish level, (3) existing utility infrastructure (adding new service connections adds cost), (4) site conditions (slope, soil, access), and (5) permit and design fees. ### Cost & Permitting Are there hidden costs in ADU construction in Arlington? Common unexpected costs include utility connection upgrades, soil remediation, structural reinforcement for interior conversions, and permit revision cycles. Berriz Design Build conducts a thorough site evaluation before providing estimates to identify these factors upfront. Does an ADU increase my Arlington property value? Yes. A well-designed ADU in Arlington typically adds $150,000–$300,000 to property value depending on type and quality. Rental income potential also contributes to the investment case. Berriz Design Build designs ADUs with both livability and resale value in mind. ### Process & Partnership Can I finance an ADU in Arlington? Yes. Common financing options include home equity loans, HELOCs, cash-out refinancing, and construction loans. Some lenders offer ADU-specific financing products. Berriz Design Build can connect you with lenders experienced in Northern Virginia ADU financing. How do I get an accurate ADU cost estimate for my Arlington property? The most accurate estimate requires a site visit and zoning analysis. Berriz Design Build conducts initial consultations to evaluate your lot, existing infrastructure, and goals before providing a detailed estimate. Use our Pricing Guide for current ranges, then connect with us for a property-specific assessment. 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Design, permitting and construction handled by one accountable group — no hand-offs, no finger-pointing. Request a Consultation Call (703) 552-7565 Chat With Us Now Pricing Guide ↗ The Berriz Way ↗ See Our Work --- *Berriz Design Build, LLC, Arlington VA. Design/build remodeling since 1994. (703) 552-7565*