1 Bedroom ADU Floor Plans (450–550 Sq Ft)
The layouts we actually build for one-bedroom ADUs in Orange County — who they suit, what they cost, and how to choose between them.
A 1 bedroom ADU typically runs 450–600 sq ft — a real bedroom with a door, a full bath, and an open kitchen-living space. It’s the sweet spot for a single tenant or couple: big enough to rent strongly, small enough to fit most Orange County backyards and preserve yard space. We build two proven one-bedroom plans — The Laguna (450 sq ft) and The Balboa (550 sq ft) — both customizable to your lot.
The plans
The Laguna
450 sq ft · 1 bed / 1 bath
Indoor-outdoor living — compact footprint that keeps the yard
See the full plan
The Balboa
550 sq ft · 1 bed / 1 bath
Live/work layout with room for a desk or reading corner
See the full plan
Every plan links to its full page with the 3D layout, specs and what’s included. Browse all sizes on the ADU floor plans hub, or compare 2 bedroom ADU floor plans.
Who a 1-bedroom suits
A single tenant, a couple, a parent living close, or a home office that can become a rental. One-bedroom units hit the strongest rent-per-square-foot in most OC cities because the expensive rooms — kitchen and bath — are spread over fewer square feet.
What it costs
At the published 2026 rates — $270–$380/sq ft for a custom detached build — a 450–550 sq ft detached one-bedroom typically lands in the $200K–$210K starting band; a garage conversion of similar size runs $90K–$150K. Run your size in the cost calculator.
Detached or conversion?
Both plans work as standalone backyard homes; a 2-car garage (~400–500 sq ft) converts naturally into a one-bedroom layout. The deciding factors are slab condition, panel capacity and how much yard you want to keep — we measure all three on the free site visit.
Which plan fits your lot?
Free on-site assessment — we check setbacks, utilities and access, then recommend the layout that earns its square footage.