Cost to convert a basement into an in-law apartment in Berkeley, CA

Johanna, a homeowner in Berkeley, contacted New Avenue to create a basement apartment for her mother-in-law. The family needed a space that would make it easy for Johanna’s mother-in-law to get around using her walker,.

New Avenue created custom plans to expand the basement and convert it into an ADU. The basement ADU features a kitchen/living area, a bedroom/office, and a bathroom with a large shower.

The family also wanted to reserve part of the basement for storage and laundry. When their New Avenue design professional created the design, he found a way to relocate the washer and dryer to maintain a shared storage and laundry space.

At the time of this project in 2015, the cost for design and permitting was $44,360. The construction budget was $387,000.

Above: A floorplan of the existing basement, before the ADU was built.

Above: A floorplan for the new ADU

Converting a basement to a living space: where to start

The best way to start your project is to talk to a full-service design/build firm with experience building in your area.

New Avenue Homes has over twelve years of experience and 750 projects in the Bay Area. Our experience and system make it possible for us to provide the most accurate pricing and the most comprehensive service in the industry. Our turnkey pricing includes everything you need to transform your home: team creation, design, engineering, permitting, materials, and construction.

Use our vetted design/build professionals or bring in your own. With the New Avenue system, everyone is part of a cohesive team working to make your project happen on time, on budget, and without unnecessary surprises.

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