Trusted ADU contractors in California and Washington

The full process of designing, permitting, and constructing a new accessory dwelling unit (ADU) typically takes 10 to 16 months, depending on the complexity of your project, city processing times, and coordination with you throughout each phase. Here’s a general breakdown:

● Design & Permitting: 2 to 4 months
This typically includes concept plans, schematic and design development, and Title 24 compliance. Multiple design meetings and revisions are typically included during this phase to ensure your vision is fully incorporated in the design.

● Permitting: 3 to 4 months
Once plans are submitted, the city reviews them in plan check cycles. Timelines vary by jurisdiction and can depend on the city’s backlog as well, and may include revisions to the plans based on city feedback before final permit issuance.

● Construction: 5 to 8 months
Construction duration typically depends on unit size, complexity, site conditions, and city inspection timelines. This includes everything from site prep and framing to MEP installation, finishes, and the final Certificate of Occupancy.

We aim to complete ADU projects in 10 to 12 months whenever feasible, but always advise planning for up to 16 months to account for external delays.

In California, the maximum size of your ADU depends on whether it’s attached or detached, your lot size, and your local city or county’s zoning regulations.

• Detached ADUs are allowed up to 1,200 sq. ft. in many areas, but state law requires all jurisdictions to permit at least 800 sq. ft., regardless of lot coverage, setbacks, or floor area ratio limits.
• Attached ADUs can typically be up to 50% of the size of your primary home, but must be allowed at least 800 sq. ft., even if 50% would be less.

Local ordinances may allow more—but cannot restrict you below these state minimums. Every property is unique and may have specific conditions—such as lot configuration, easements, setbacks, or local overlays—that impact the maximum ADU size.

We offer a free property-specific assessment as part of our initial process—even before a contract is signed—to help define your scope and guide you clearly. Contact us at (559) 412-8841 or info@urbatect.com, and we’ll assess your site to confirm the maximum ADU size allowed under your city’s rules.

Adding an ADU is not just a smart way to maximize your property—it’s a long-term investment that boosts value, generates income, and offers greater flexibility for your evolving needs. Here’s why building an ADU makes strong financial sense:

• Boosts overall property value
• Builds equity immediately by adding livable square footage and a permitted unit to your asset
• Strong return on investment (ROI) in both resale and rental markets
• Generates passive rental income - short- or long-term
• Offers flexibility for future use (guest house, home office, aging parents, etc.)
• Provides private space for family or visitors
• More cost-effective than buying a new property or undertaking major home additions
• Adds diversification to your real estate investment portfolio
• Supports sustainable living with compact, energy-efficient design options

No—owner-occupancy requirements have been eliminated for ADUs across California, with the exception of Junior ADUs (JADUs). This means you’re not required to live on the property to rent out your ADU. However, JADUs still require the property owner to reside on-site, either in the main home or the JADU.

Not necessarily. While pre-approved plans can be faster to permit, they still need to meet your specific site conditions and local city regulations, which can result in costly changes or delays if they don’t align perfectly. At Urbatect, we specialize in custom solutions that are designed to minimize revisions, avoid surprises, and ensure smoother permitting—helping you save time and money in the long run.