Detached & Attached ADUs
built right, from day one.
We design, permit, and build both detached and attached ADUs from the ground up — fully permitted, beautifully finished, and ready to generate rental income from day one.
ADU Construction
Detached & Attached
An Accessory Dwelling Unit (ADU) is a fully independent living space built on the same lot as an existing single-family home. ADUs come in two forms: detached (a standalone structure separate from the main house) and attached (built onto or connected to the primary residence, including garage conversions). In California — and especially across Los Angeles — ADUs have become one of the most powerful financial tools available to homeowners.
Whether you're building to generate rental income, house a family member, or maximize your property's value, a well-designed ADU delivers returns that few other investments can match. Arc Design Build handles every phase in-house: architecture, permits, structural engineering, and construction — so you never coordinate multiple contractors.
Our ADUs are fully detached, fully permitted, and finished to the same quality standards as the primary home. From permit submission to final inspection, you track every phase through Arc Studio, your dedicated client portal.
Our process.
Everything you need
to know.
Permitting: 3–6 months. Construction: 10–18 weeks after permits. Total timeline: 8–12 months from contract to move-in.
California allows ADUs up to 1,200 sq ft on most single-family lots. Your specific lot may allow more or less based on setbacks and lot coverage.
California eliminated owner-occupancy requirements through 2025. You may rent both the main home and the ADU simultaneously.
Expect $220–$400/sq ft in Los Angeles depending on finishes, lot conditions, and structural complexity.
Yes — completely. We submit, manage, and respond to all plan check comments. You never interact with the city building department.
Ready to build your
adu project?
Configure your project online and get a realistic budget estimate before your first call with us.