Detached ADUs
A separate dwelling in the backyard or elsewhere on the lot.
ADUs
Bay Area ADU Services
GPJ Residential helps homeowners and property owners evaluate, permit, engineer, and build ADU projects, including detached ADUs, garage conversions, attached ADUs, junior ADUs, and multifamily ADU opportunities.
The free ADU screen is a preliminary planning tool. It is not permit approval, engineering design, legal advice, or a construction estimate.
ADU project types
Garage conversions
Turning an existing garage into living space, with the structural and permit issues that come with it.
Attached ADUs
An addition-style unit connected to the existing home.
Interior / Junior ADUs
A unit created within the existing house, often using a bedroom and an existing entrance.
Basement or lower-level conversions
Converting below-grade or downhill space when the building and site can support it.
Multifamily ADUs
ADU opportunities on duplex, triplex, and larger residential properties.
ADU planning tools
The free ADU screen is a preliminary planning tool. It is not permit approval, engineering design, legal advice, or a construction estimate.
Free
Free Preliminary ADU Screen
A quick questionnaire that helps homeowners understand whether a property may be worth exploring for an ADU based on basic California ADU concepts, public information where available, and user-provided property details.
Start Free ADU Screen$49
$49 Local ADU Permit Path Snapshot
A human-reviewed desktop snapshot that checks the local permit path, property information, obvious red flags, and next steps using official city/county sources and public records where available.
Request a $49 SnapshotScoped after review
Detailed ADU Feasibility Report
A deeper review for homeowners, buyers, or agents who need a more complete decision memo before moving forward with design, permits, or construction.
Request Detailed FeasibilityEngineering and construction support after feasibility
If an ADU looks worth pursuing, GPJ Residential can help with structural and civil engineering, permit drawings, construction support, and existing-condition work. ADUs sit alongside decks, additions, new homes, and repairs.
Engineering and construction after feasibilityReady to talk through an ADU?
Start an ADU project inquiry, or use the free preliminary screen if you want a first-pass look.
Start ADU Inquiry