ADU Directory

400 sqft ADU Floor Plans

400 sqft ADUs offer a specific tradeoff between living space, cost, and lot impact. Browse 2 400 sqft designs available from verified builders.

The Cottage 400
The Cottage 400
from $130k
Efficient 400 sqft one-bedroom
400 sqft1 BR1 BA
The Garage Studio 400
The Garage Studio 400
from $90k
Studio garage conversion
400 sqftStudio1 BA