LOCATION: Rio Grande, Puerto Rico
Category: Small Footprint
Builder: Peter Medero
Architect: Abruña & Musgrave, Architects
This 96-square-foot Nano-Ecohouse was designed using 16 plywood modules that were prefabricated and easily assembled at the site by the gardener who tends the property. Bolts and screws were used so that the structure can be quickly disassembled for relocation. The foundation system consists of nine 5-gallon pails of concrete. The roof is insulated with EPS panels.
Tall window openings and double doors allow for natural daylighting and cross ventilation. A 50-gallon rainwater cistern supplies the minimal water requirements for the unit. The electrical system is based on independently installed solar lamps and a 500-watt battery charged through a USB plug and/or at the owner’s permanent residence fitted with a photovoltaic system.
LOCATION: Kansas City, Kansas
Category: General
Builder: Tartan Residential Inc.
Architect: Urban Architectural Group
The primary goal of this project was to create a highly energy-efficient complex, focusing on operational efficiency. Key to the 115-unit project’s success were the innovative design and structural engineering techniques, including top chord-hanging trusses for the floors, to optimize Structural Insulated Panels (SIPs) as a core component of the exterior walls.
The use of 4.625-inch EPS core wall panels ensures excellent insulation and structural integrity. The energy efficiency of the buildings is highlighted by HERS scores of 45 for the 2-bedroom units and 47 for the 3-bedroom units, with an ACH50 rating of 1.75. Air source heat pumps provide efficient heating and cooling, and future solar panel installations are planned to achieve full net zero compliance.
LOCATION: Biddeford Pool, Maine
Category: Off-Site Construction
Builder/Architect: Unity Homes
This home—Värm, or Scandinavian-inspired farmhouse design—was built to honor the architectural traditions of its neighborhood while creating an energy-efficient space where family could gather. It was prefabricated in Unity Homes’ 100 percent solar-powered factory in Keene, New Hampshire.
The site prep work and panel fabrication could be completed simultaneously, minimizing disruption to the neighborhood. The home’s high-performance shell was then quickly raised on site and made weather-tight in just two weeks in April 2023.
With exposed timbers and European tilt-turn windows, the interior is filled with year-round light and warmth. It’s also on its way to net zero: For the six-month period since the installation of solar panels, the owners used 2.7 MWh and sent 4.16 MWh back into the grid.
LOCATION: Austin, Texas
Category: General
Builder: Younger Homes
Architect: Danze & Davis Architects
This project embodies sustainable luxury through its two connected residences. At the core of this property is a 30,000-gallon rainwater harvesting system, capable of capturing up to 6,000 gallons per inch of rainfall from the main residence, supporting irrigation, potable use, and gardens on the 11-acre property.
Solar energy is generated by discreetly positioned ground-mounted photovoltaic panels. For energy independence and resilience, the home integrates its own well for fresh water, with the option to use city water. A Generac generator provides backup power.
A mudroom supports an eco-conscious lifestyle with a built-in water bottle filler that uses rainwater collected on the property. A guest home is designed for generational living, incorporating features that make efficient use of resources.