Basement ADU

Basement ADU conversion in San Diego.

+1-619-330-8185

TRUSTED BY SAN DIEGO HOMEOWNERS

Our Credentials & Reviews

★★★★★

5.0 Rating

★★★★★

5.0 Rating

Preferred Contractor

A+ Rating

★★★★★

5-Star Business

NRCA Member

Recent Project

Completed modern detached ADU in San Diego backyard

Before

After

Detached 400 sq ft ADU — San Diego backyard, permits included

Unlock Hidden Value

Peak Builders converts basements into legal ADUs throughout San Diego. Many San Diego homes have basements that are perfect for conversion—they already have the space, just need the right upgrades to become income-generating living units.

Use existing square footage

Most affordable ADU type

Natural climate control

No lot space required

Often already partially finished

Peak Builders & Roofers of San Diego provides professional basement adu services throughout San Diego. Our experienced team delivers quality workmanship and reliable results for every project. We understand the specific needs of San Diego homes and tailor our approach accordingly.

We stand behind our work with clear communication, fair pricing, and attention to detail. Every project receives the same level of care, from initial consultation through final walkthrough. Your satisfaction is backed by our warranties and responsive service team.

Our Work

Basement ADU Conversion in San Diego — Project Photos

Garage conversion to ADU interior San Diego

Why Choose Us

Quality Craftsmanship You Can Trust

With over 15 years of experience serving San Diego homeowners, we bring expertise, quality materials, and exceptional craftsmanship to every project. Our team is fully licensed, bonded, and insured for your peace of mind.

Your project, our proven process.

Free Consultation

We visit your home, discuss your vision, and provide a detailed estimate with no obligation.

Design & Planning

Our team creates custom plans and handles all permits with the city of San Diego.

Expert Construction

Licensed craftsmen bring your project to life with quality materials and workmanship.

Final Walkthrough

Inspection, quality assurance, and warranty coverage ensure your complete satisfaction.

Basement ADU Options

Unfinished Basement Conversion

Complete transformation from raw space to finished ADU with all amenities.

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Finished Basement Upgrade

Add kitchen, separate entrance, and code requirements to existing finished basement.

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Walkout Basement ADU

Capitalize on existing walkout access for easy separate entrance.

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Garden Level ADU

Add window wells and egress to create bright, legal living space.

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Testimonials

Real projects. Real results.

Hear from San Diego homeowners who trusted Peak Builders with their most important investment.

Sarah M.

Peak Builders transformed our outdated kitchen into a stunning modern space. Their attention to detail and craftsmanship exceeded our expectations.

Kitchen Remodel, San Diego

Michael & Jennifer T.

We hired Peak Builders to finish our basement and couldn't be happier. They handled permits, design, and construction seamlessly.

Basement Finishing, Poway

Robert K.

After a hail storm damaged our roof, Peak Builders made the insurance process easy. They documented everything and installed a beautiful new roof.

Roof Replacement, Chula Vista

Lisa & David P.

Our master bathroom went from dated to spa-like thanks to Peak Builders. The frameless shower and heated floors are exactly what we envisioned.

Master Bath Renovation, Oceanside

James H.

Peak Builders built an ADU in our backyard that's now generating rental income. They navigated San Diego's permit process expertly.

ADU Construction, San Diego

Amanda R.

We bought a 1970s home and Peak Builders helped us transform every room. It's like a brand new house. Amazing team!

Full Home Remodel, Vista

Carlos & Maria G.

Our outdoor kitchen from Peak Builders is the envy of the neighborhood. Built-in grill, pizza oven, and beautiful stone counters.

Outdoor Kitchen, Escondido

Patricia W.

Peak Builders remodeled our kitchen and two bathrooms. Having one contractor for the whole project made everything easier.

Kitchen & Bath Combo, Carlsbad

Thomas & Susan B.

We added a second story to our ranch home. Peak Builders matched the new addition perfectly to our existing home.

Home Addition, Santee

Read All 12+ Reviews

Basement ADU FAQs

Most basements can be converted, but ceiling height is the main constraint — California and Colorado require a minimum of 7 feet for a legal bedroom. Egress (a window or door large enough to exit in an emergency) is also required. We assess both during the site visit.

Yes, if it includes a bedroom. An egress window must meet minimum opening dimensions for emergency escape. This may require excavation and concrete cutting depending on your existing foundation.

Waterproofing before finishing is non-negotiable. We assess the existing drainage, install interior or exterior waterproofing as needed, and use moisture-resistant materials (cement board, moisture-barrier paint). A dehumidifier is standard in basement ADUs.

It depends on the market and the unit. A well-finished basement ADU with good natural light (egress windows help), separate entrance, and quality finishes rents well. Ground-level or above-grade detached units command premium rents in most markets.