Dorothy ADU

In Arlington, Massachusetts, Reframe Systems applied our technology-enabled homebuilding platform to turn an underutilized residential lot into a high-performance affordable home. Completed in June 2024, the 900-square-foot Dorothy ADU was delivered for the Housing Corporation of Arlington, replacing an existing garage with a net-positive, Passive House-certified home.

The compact two-story home is warm and highly livable, with two bedrooms, 1.5 bathrooms, a full kitchen, comfortable living spaces, thoughtful storage, and modern finishes. Large windows and sliding doors bring in natural light and create a bright, spacious feel for residents. 

Dorothy is all-electric, solar-powered, and battery-equipped, with an airtight envelope that helped earn PHIUS Zero Passive House certification. At 20% more airtight than the Passive House threshold, the home is designed to reduce drafts, improve comfort, and use less energy day to day. With a HERS score of -25, the home produces more electricity through rooftop solar than it consumes. That translates into lower operating costs for the owner and a more comfortable, efficient home for residents.

The home was designed, built, and delivered through our Design for Manufacturing and Assembly process, where design intent, production requirements, and field execution are coordinated at the software level through final assembly. Factory production enabled tighter tolerances, more predictable sequencing, and high-quality finishes completed before the home arrived on site, allowing the project to move from groundbreaking to completion in just 48 days, approximately 2.5x faster than a comparable traditional timeline.

Completed with a 60% apprentice builder workforce, Dorothy demonstrated how a software-guided process can maintain quality while expanding participation in high-performance homebuilding. By delivering the right information at the right time, the platform enables less-experienced workers to contribute effectively without relying solely on scarce specialized labor.

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