The US is in the middle of a severe housing affordability crisis, largely due to a supply shortage that is difficult to address in a timely manner with traditional subsidies and construction methods. Today, home building still relies predominantly on the traditional, site-built construction process. However, the on-site construction industry features growing productivity inefficiencies due to its significant fragmentation and a critical shortage of skilled construction labor. In addition, construction costs have increased over time, making it even more challenging for developers to add new affordable units to the housing market. …Modular building, if brought to scale, has the potential to reduce construction costs and make it more affordable to build new homes, especially in areas experiencing severe affordable housing shortages. …With coordinated initiatives by governments at all levels, bringing modular building to scale could also contribute to making the housing stock more resilient and sustainable relative to the challenges presented by climate change.