Also known as accessory dwelling units (ADUs), these small, standalone units, typically 600 to 1,200 square feet, are gaining popularity as housing costs rise.

A bipartisan bill introduced by Congressmen Sam Liccardo and Andrew Garbarino would create government-backed loans to help homeowners build ADUs on their property, reducing the risk for lenders by guaranteeing part of the loan in case of default.

Backed by both parties and major industry groups, the bill comes as the US faces a shortage of four million homes. ADU supporters see them as a practical, fast-track solution to help ease the national housing crisis.