Detached vs. Attached ADU: Which Type Is Right for Your Property?

The right ADU type depends on your lot, budget, and goals. Each option offers a distinct balance of privacy, cost, and complexity.

A detached backyard cottage delivers the most privacy and flexibility, making it ideal for rental income or multi-generational living. It's typically the most expensive option because it's ground-up new construction with its own foundation and utilities.

A garage conversion reuses an existing structure, often lowering costs while still providing a separate, private unit. Success depends on the garage's condition, size, and whether it can meet code for habitable space.

A basement conversion is frequently the most affordable path when you have suitable ceiling height and egress. It keeps the ADU connected to the main house, which suits family members more than arms-length tenants.

An attached addition extends the primary dwelling and can be cost-effective, though it offers less separation. Weigh privacy, construction cost, and how you intend to use the space before committing to a type.