A detached accessory dwelling unit is a fully independent residential structure built separately from the primary home. It requires its own foundation, framing system, and utility connections. Unlike a garage conversion, it functions as a standalone residence from both a structural and permitting standpoint.
Detached ADUs demand careful site planning and coordinated submissions from the beginning. When sequencing is handled properly, construction moves predictably.
Full permit management from site plan through final inspection.
Privacy and independence. A detached unit does not share walls or systems with the primary residence. That separation increases privacy for occupants and simplifies rental arrangements. For long-term tenants, a standalone structure often carries stronger appeal than attached options. For family use, it allows independence without distance.
Property fit. Detached ADUs work well on properties with adequate rear or side yard space. Placement can preserve the interior of the main home during construction while creating clearly defined access and outdoor areas.
Long-term utility. Adding a separate structure increases functional square footage. Whether used for rental income, multigenerational housing, or flexible workspace, detached units expand how a property is used over time.
No shared walls, foundation, or mechanical systems with the main residence.
Standalone units command stronger rental interest and support long-term tenancy.
A permitted independent dwelling adds a legal functional unit at resale.
Guest housing, home office, multigenerational living, or future downsizing option.
Detached ADU construction begins with zoning verification. Even under California’s ADU framework, local jurisdictions across the Peninsula and East Bay apply review standards differently. A site plan must be accurate. Minor measurement errors can trigger corrections during plan check.
Detached units require full code compliance as independent structures. That includes proper foundation design, lateral bracing for seismic stability, structural anchoring, and Title 24 energy documentation.
On hillside or irregular lots common in this region, grading, drainage, and easements can limit buildable area. Feasibility must precede design decisions.
We verify setbacks, lot coverage, and zoning before design begins.
Infrastructure planning often determines whether a detached ADU proceeds smoothly. Electrical service upgrades are common in older homes throughout Santa Clara and San Mateo counties. Early coordination with utility providers prevents mid-project redesign.
Utility routing should be addressed before permit submission, not during excavation.
Detached ADUs require sequencing. We structure projects accordingly — feasibility first, then coordinated planning, permitting, and phased construction.
We verify setbacks, evaluate site constraints, and review infrastructure capacity before design begins.Accurate measurement prevents redesign during review.
Architectural design is coordinated with structural requirements and utility routing from the outset.
Submissions are organized and complete. Prompt responses to plan check comments reduce unnecessary review cycles.We manage all city communication.
Work proceeds in defined phases — foundation, framing, inspections, mechanicals, finishes — with scheduled coordination between trades.
Most detached ADU problems are planning problems. Setbacks get assumed instead of verified. Utilities are estimated instead of inspected. Engineering gets added after design instead of integrated from the beginning.
When feasibility, engineering, and permitting are aligned early, the build phase is straightforward. Detached ADUs reward preparation.
“Most detached ADU problems I see aren’t construction problems. They’re planning problems.”
— Dan Mendez, Owner
Each city has its own zoning interpretation, setback standards, and review process. We build detached ADUs across the Peninsula, South Bay, and East Bay with city-specific permit familiarity.
Not every property suits a detached unit. We build every ADU type — evaluate which option fits your lot, zoning, and goals.
Built as an extension of the existing home. Shares at least one wall. Often a fit when rear yard space is limited.
JADU DetailsConvert an existing garage into permitted living space. Uses the existing footprint to reduce new construction scope.
Garage Conversion DetailsPermit coordination, plan check responses, and city communication managed from submission through final inspection.
Permitting ProcessIf you’re evaluating a detached ADU on your property, start with feasibility. We’ll review zoning constraints, lot layout, and infrastructure requirements before plans are developed.
Clear evaluation · Structured planning · Coordinated execution
Serving Palo Alto · Mountain View · San Mateo
Walnut Creek · Redwood City · the Bay