A new modular Passive House retrofit system developed by CO Adaptive aims to make high-performance building upgrades faster, cheaper and more accessible. The system, called “The Block,” is designed to simplify energy-efficient retrofits by using prefabricated panels made from salvaged wood that can be assembled quickly inside existing buildings.
The innovation seeks to address one of the biggest challenges in sustainable architecture—retrofitting older buildings to meet Passive House energy standards without costly and disruptive construction.
Prototype installed on Governors Island
A prototype of The Block has been installed at the Arts Center at Governors Island in New York City as part of the Climate Solutions Piloting Program run by the Trust for Governors Island.
Researchers will conduct air-leakage and thermal performance tests over the next year to evaluate the system’s effectiveness.
If the tests prove successful, the modular wall solution could provide a scalable approach to reducing carbon emissions from existing buildings, particularly in dense urban environments.
How the modular wall system works
The Block system consists of insulated prefabricated panels installed on the interior side of existing exterior walls.
Key features include:
- Panels built from salvaged framing lumber
- Quick assembly and disassembly capability
- Creation of an airtight thermal barrier
- No modification required to the existing building façade
This approach is especially valuable in cities like New York City, where many buildings are located in historic districts with protected façades that limit exterior alterations.
Supporting circular construction practices
CO Adaptive, founded in 2015 by architects Ruth Mandl and Bobby Johnston, focuses on Passive House retrofits and adaptive reuse projects.
The firm also launched Co‑Disassembly, a service that carefully deconstructs buildings to recover reusable materials before redevelopment.
This circular construction model aims to reduce waste and reuse building components in new projects, helping to lower the embodied carbon associated with producing new materials.
Addressing climate and waste challenges
Buildings are responsible for nearly 40% of global carbon emissions, much of which comes from producing materials such as steel, concrete and insulation.
At the same time, construction and demolition debris represents the largest waste stream in many regions. In New York, landfills are projected to reach capacity within the next 16 to 25 years.
Innovations like The Block could help address both problems by:
- Reducing the need for new building materials
- Improving energy efficiency in older buildings
- Diverting construction waste from landfills
Expanding access to energy-efficient housing
By allowing retrofits without altering exterior walls, the system could make Passive House–level upgrades feasible for more buildings, including:
- Older tenement housing
- Rental apartments
- Public housing developments
If widely adopted, the modular Passive House retrofit system could play an important role in decarbonizing aging urban housing stock while making sustainable building upgrades more accessible to a broader range of property owners and residents.
