Portland residents in search of an energy-efficient home need look no further than Lightbox 23, the new net-zero project from Lightbox Portland and Steelhead Architecture. A speculative development project in northeast Portland, Lightbox 23 has two units and numerous sustainable features, including super-insulated walls, high-performance ventilation systems, and two 10-kW solar arrays. But sustainablity isn’t the project’s only draw – it also boasts beautiful design and stunning views of Mt. St. Helens’ and Mt. Adams’ snow-capped peaks.

Left image of floating staircase, right image of living space with chairs and large windows
Bathroom with all white decoration and windows at top
A set of floating stairs, which provides access from each floor to the half-levels above and below, serves as the duplex’s backbone. A deck on the building’s north side can be accessed from the exterior. From this deck, residents can enjoy the open air and, on a clear day, the distant peaks of the two mountains.

The facade of a chunky modern home

Side view of a boxy modern home with black and yellow paneling

Related: Net-zero Acacia Avenue House saves up to 90% of heating and cooling costs

While the solar array on top of the building provides the building with its energy, part of making the project net-zero included finding ways to reduce the energy load overall. To tackle this problem, Steelhead Architecture turned to affordable super-insulation. Each unit has two-by-eight walls filled with blown-in cellulose, along with two inches of rigid insulation affixed to the exterior of the plywood. The concrete slabs have 3 more inches of rigid insulation. The roof construction has a similar mix of insulation, which eliminates the need for any vents.

man on exterior deck with furniture and city views

The home’s mechanical system further supports the unit’s net-zero goals. All-electric ducted heat pumps, which are much more efficient than gas systems, provide heat for the apartments. Furthermore, nothing on the project uses gas at all. A heat recovery ventilator with its own ducts effectively controls air exchanges with zero energy loss. To ensure a low heat/cooling loss, the architects sought out leaks and used repetitive joint sealing, further reducing the project’s energy use.

The facade of a chunky modern home

Lightbox 23 is an exploratory project of Lightbox Portland, which is devoted to high performance, high-density modern progress. There are three additional Lightbox Portland/Steelhead Architecture projects presently underway.

+ Steelhead Architecture

Images via Josh Partee Photography