We have developed the technologies to provide heating, cooling, humidity control and ventilation with very minimal energy use. 

A key to making this technology work is how well we construct or retrofit the shell, or envelope, of our buildings; the six sides of our structures: floor, four walls and the roof. 

The biggest source of heat loss is the building envelope. Without proper air sealing, the air that we heat in the winter travels to the outside, and the warm humid air in the summer travels to the inside. In order to seal this airflow—and to make the building envelop more resilient to the thermal exchange of energy—the building industry went down a deep rabbit hole of relying on fossil fuel-based foam plastics—a high embodied carbon material—to provide that thermal layer. By using foam plastic materials, we were successful in reducing operational greenhouse gas emissions, but at the cost of rising emissions from the material choices.

Reducing the upfront carbon emissions from materials has become the most critical step to take to continue to draw down the carbon emissions from our built environment.

This edition of the River Reporter’s Sustainability section gives the reader a rich overview of why low embodied-carbon building materials are both healthier for the people who dwell within our homes and work in our workplaces—and better for the environment. 

Stephen Stuart is the lead instructor for Yestermorrow Design/Build School’s certificate course in Building Science and Net Zero Design.