GatherADU

What is an ADU?

An ADU (Accessory Dwelling Unit) is a secondary housing unit on your property. Also known as granny flats, in-law suites, casitas, or backyard homes, ADUs provide independent living space with their own entrance, kitchen, and bathroom.

How much does it cost to build an ADU in California?

ADU costs in California typically range from $150,000 to $400,000, depending on size (400-1,200 sq ft), finishes, and site conditions. Garage conversions are often the most affordable option starting around $80,000-$150,000.

How long does it take to build an ADU?

A typical ADU project takes 8-14 months from consultation to move-in. This includes 2-4 weeks for design, 60-90 days for permitting, and 4-6 months for construction.

Do I need a permit to build an ADU?

Yes, ADUs require building permits in California. However, state laws have streamlined the process, requiring cities to approve most ADU applications within 60 days. GatherADU handles the entire permitting process for you.

Can I rent out my ADU?

Yes, you can rent out your ADU in most California cities. ADUs typically generate $1,500-$3,500 per month in rental income depending on location and size. Short-term rentals (Airbnb) may have additional restrictions in some cities.

What is the maximum size for an ADU in California?

Detached ADUs can be up to 1,200 sq ft. Attached ADUs can be up to 1,000 sq ft or 50% of the primary dwelling, whichever is less. JADUs (Junior ADUs) are limited to 500 sq ft and must be within the existing home.

What is a garage conversion ADU?

A garage conversion transforms your existing garage into a livable ADU with a bedroom, bathroom, and kitchen. This is often the most cost-effective ADU option since the basic structure already exists.

Will building an ADU increase my property taxes?

Yes, but only on the added value of the ADU itself, not your entire property. Under Proposition 13, your main home assessed value remains protected. Typical tax increases range from $2,000-$4,500 annually.