Start with what your city allows

Before comparing ADU plans, check the local rules for maximum size, height, setbacks, parking, utilities, rental use, and owner occupancy. A beautiful backyard cottage plan is only useful if the lot can legally support it.

• Confirm maximum floor area and lot coverage.
• Check side-yard and rear-yard setbacks.
• Ask if separate water, sewer, or electric service is required.
• Confirm whether long-term or short-term rental use is allowed.

Compare plans by privacy and daily living

Small homes need thoughtful layouts. Look for a real kitchen, bedroom privacy, natural light, storage, laundry access, and an entry that does not point directly into the main house’s private space.

A compact plan with good storage and a calm bedroom can live better than a larger plan with awkward circulation.

Use a shortlist before buying

Shortlist three ADU plans: one smallest legal plan, one most rentable plan, and one family-friendly plan. Then ask a builder which one is easiest to build on your site.