Hidden behind the restored 1924 cottage, the West 7th duplex is a shining example of sustainable urban living in Austin. Built into nearly 20 feet of grade change on a narrow 50-foot-wide lot, the 5,650-square-foot structure contains two spacious family homes—a 3,813-square-foot primary residence and a 1,687-square-foot secondary unit—each oriented to maximize natural light, privacy and outdoor connection. Together with the historic front cottage, the property provides healthy, efficient homes for three families, reimagining what density can look like within a historic district. 

This PHIUS-certified Passive House is the largest of its kind in the southern United States and serves as a demonstration project for how sustainability and preservation can coexist. Featuring warm wood interiors, skylights and expansive glazing that frame views while maintaining privacy, the duplex embodies the latest thinking in design and building science, prioritizing homes that are healthier, safer and more resilient than conventional construction. 

The project’s steep hillside and tight lot presented both challenge and opportunity. By leveraging the topography, Forge Craft created five staggered levels, offsetting the garages by six feet to integrate with the terrain. Layered courtyards, terraces and private gardens provide each home with its own outdoor sanctuary while maintaining a compact urban footprint. Garage access was discreetly integrated from the rear alley, preserving the historic streetscape and keeping the new construction largely hidden from view. 

Meeting Passive House standards meant pushing the limits of high-performance design. The envelope features continuous exterior insulation, recycled cellulose cavity insulation, air sealing to roughly 10x tighter than a standard new home, and high performance Marvin windows, reducing operational usage significantly. All-electric systems, heat pumps, a metal roof, and net-zero–ready infrastructure ensure long-term resilience and comfort. The project reached certification with only a modest 2.5% cost increase—proof that performance is attainable and economical, even in challenging climates. 

Bringing this complex design to life required close collaboration between Forge Craft, Form to Finish (builder), Positive Energy (mechanical design), New Results HVAC, city officials, and multiple oversight bodies. Together, the team navigated ADU regulations, historic review processes, and site constraints to deliver a project that balances innovation with contextual sensitivity. 

With native landscaping, a comprehensive stormwater capture and reuse system and thoughtfully designed outdoor spaces, the West 7th duplex transforms a once-crumbling hillside lot into a model for climate-conscious density, that is now home to three families in Austin’s urban core.