The Englewood Passive House Duplex is a pioneering two-unit, three-story residence that transformed a challenging urban site into a model of high-performance, low-energy living. Situated adjacent to a busy highway, the design addresses acoustic and visual impacts through airtight assemblies, super-insulation, and strategic fenestration—all meeting Passive House standards—to create a serene, healthy indoor environment.
Each all-electric unit maximizes comfort and energy efficiency through a super-insulated envelope, energy recovery ventilation (ERV), and high-performance triple-pane windows. South-facing windows and skylights flood the interiors with daylight while passive solar gain warms the home naturally, and operable windows enable fresh air and passive cooling. Semi-private outdoor spaces and west-facing balconies offer sweeping views of the Rocky Mountains while providing privacy and connection to the surrounding context.
Morgan Law
Steve Scribner
Maggie Wohltjen
Sterling Builders
EMU Systems
Kylie Fitts and Drew Tooley
2,950 sf
Englewood, CO
- Technology Designer: Article
- 2023 AIA Colorado Design Award of Excellence and Sustainability Recognition
- Modern in Denver: Article
- Rocky Mountain PBS: Feature
The bold yet pragmatic design combines thermally-modified wood and metal siding with careful massing and orientation to optimize energy performance, acoustic shielding, and durability. Airtight construction and passive detailing prevent condensation, mold, and sound intrusion, ensuring a resilient, long-lasting home. Embodied carbon was minimized through wood construction, dense-pack insulation, and a concrete-free floor system, while finishes like real wood flooring and durable ash siding reinforce longevity.
Designed from the outset for Passive House certification—the first multifamily PHI-certified project in Colorado—the duplex achieves exceptional energy performance, cutting heating and cooling demand by 90% compared to typical buildings with 0.28 air changes at 50 Pa. Collaboration with building performance specialists optimized assemblies, volumes, and shared mass to maximize efficiency. The project also created an educational opportunity for the builder and the green building community, coinciding with the Marshall Fire rebuild and inspiring wider adoption of Passive House practices in Colorado.
With all-electric systems, extreme airtightness, and high-quality ventilation, the duplex protects residents from highway noise, smoke, and pollutants while minimizing carbon impact. By optimizing a single site, the project delivers flexible, high-density urban living with spaces suited for modern generational living, demonstrating that comfort, sustainability, and context can coexist at the highest level.
