Detached ADUs
We build backyard units with their own entrance, kitchen, bathroom, and living space, giving you rental income or a private home for relatives while preserving your main residence.
Service guide / San Diego
San Diego ADU Construction
Plan an ADU in San Diego: detached, attached or junior units, siting on the lot, utility connections, access, design choices, and what to confirm locally.
ADU Construction in San Diego
ADU construction in San Diego is a smart way to add living space, generate rental income, and increase the long-term value of your property.
We build accessory dwelling units for aging parents, adult children, guests, or tenants, and we guide you through every step, including design, city permitting, site preparation, construction, and final inspection. Detached units, attached additions, and garage-based ADUs can all be tailored to your lot and your goals. Our team understands California and San Diego requirements, which helps your project move forward smoothly and avoid costly delays. Each ADU is designed to be efficient, comfortable, and visually consistent with your main home, using quality materials and skilled workmanship throughout. We keep you informed throughout. If you’re thinking about adding an ADU to your property, contact us today for a consultation and a clear plan for your project.
What to gather about your lot
- A site plan or survey showing property lines and easements
- Who will live in the unit and for how long
- Photos of the side yard, backyard and the path to the street
ADU Construction Services in San Diego
Attached ADUs
Add a unit connected to your home with shared walls and a separate entrance, making efficient use of your lot while keeping construction costs and utility needs manageable.
Junior ADUs
Convert existing space inside your house into a compact, self-contained suite with a small kitchen and private entry, creating flexible, affordable housing without expanding the building footprint significantly.
Design and Permitting
We prepare plans, submit applications, and work through San Diego approval requirements, helping your ADU move from concept to construction with fewer delays and fewer surprises overall.
Utilities and Infrastructure
We coordinate electrical, plumbing, sewer, and HVAC connections carefully, ensuring your new unit has reliable service, proper code compliance, and efficient systems that keep operating costs reasonable.
Quality Finishes
From flooring and cabinetry to paint and lighting fixtures, we select durable, attractive materials that make your ADU comfortable, appealing to tenants, and consistent with your main home.
ADU Construction in San Diego: Options and Applications
The right type depends on the lot, the budget and who the unit is for.
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Detached backyard unit
A freestanding cottage gives the most privacy for both households and the most freedom in layout, but it needs the most open yard and the longest utility runs.
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Attached unit
Sharing a wall with the house shortens utility connections and keeps the footprint compact, though the two homes will hear each other and the roofline has to be reconciled.
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Garage or space conversion
Turning an existing structure into living space can skip new foundation work. Parking and slab questions are covered in the garage conversions guide.
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Junior unit inside the home
A small unit carved from an existing bedroom wing usually needs a separate exterior entrance and a compact kitchen, and often relies on the main house for some systems.
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Multigenerational housing
Parents, adult children or a caregiver can live close while keeping separate doors, thermostats and daily routines.
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Long-term rental or guest quarters
Rental use can bring different local rules on occupancy and owner residence, so settle the intended use before the design is locked.
Where an ADU can sit on the lot
Siting is the first real constraint. The footprint has to clear the required distances from property lines and from the main house, avoid recorded easements, and stay out of the way of mature trees whose roots you would rather not cut. Existing sewer, water and gas lines often decide the position before any style choice does.
Slope matters too. A flat rear corner is simple to build on, while a graded or terraced yard may need a stepped slab, a retaining edge or an engineered foundation. Call 811 before any digging so buried lines are marked.
- Confirm first
- Setbacks, easements and height limits
- Locate
- Sewer lateral, water line, electrical panel
- Watch for
- Slope, tree roots and drainage paths
Materials and Design Considerations for San Diego ADU Construction
A small building leaves little room to correct a poor choice, so check these early.
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Foundation type
A slab on grade is common for a flat lot, while a raised or pier foundation can suit a slope; soil conditions drive the choice.
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Matching the main house
Stucco, siding and roof pitch that echo the existing home help the unit read as part of the property and may be required by local design standards.
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Window placement
Face glass toward your own yard and away from the neighbor's bedroom window, and plan overhangs for west sun.
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Heating and cooling
A compact unit is typically served by a ductless system sized to its own load, with insulation and glazing doing most of the work.
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Fire-resistant exterior
On lots near brush or canyons, ember-resistant vents, roofing and cladding may be expected; ask the local fire authority what applies.
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Sound and privacy
Shared walls need insulation and staggered framing, and a detached unit benefits from a screened patio so each household has its own outdoor edge.
ADU Construction Projects in San Diego: What You Should Consider
An ADU moves from paper to ground in a fairly consistent order. A site review and survey come first, then a design checked against local rules, then plan submittal to the building department, then permits, construction and inspections.
- Review the lot and utilities
- Draw plans and submit for review
- Build and pass inspections in sequence
Detached, attached, or junior unit
Three common forms, each with a different trade-off.
Detached cottage
A separate building with its own roof, foundation and yard presence.
- Most privacy
- Longest utility runs
- Needs open yard
Attached addition
A new wing sharing at least one wall with the existing house.
- Shorter connections
- Roofline tie-in
- Shared sound path
Junior unit
Part of the home converted into a compact, separately entered suite.
- Smallest footprint
- No new yard use
- Simplest to phase
Utilities, access and the yard around it
Whether the unit shares or has its own meters, how sewer capacity is evaluated, and what connection charges apply all vary by city, water district and utility. Ask each early, because a long trench to a distant sewer line can cost more than the walls of the unit.
Access deserves equal attention. A clear, lit path from the street to the unit's own front door, a place for trash bins and a plan for deliveries during construction keep daily life workable. Hardscape for that path is usually easier to plan with the building, not afterward.
- Ask the utilities
- Meters, sewer capacity, connection charges
- Plan the route
- Path, lighting and bin storage
Clarity before you begin
Frequently Asked Questions
Do I need a permit for an ADU?
Yes, a new dwelling unit goes through building review and inspections. California law encourages ADUs, but each city and county applies its own procedures, so check with your planning and building department.
Can I build one in an HOA community?
State law limits how far an association can restrict ADUs, but architectural review and other community rules may still apply to appearance and construction. Read your governing documents and ask the board early.
Does an ADU need its own utilities?
It depends on the unit type and your jurisdiction. Some units connect to the main house, others need separate service, and fees and capacity checks vary by utility. Confirm with the providers before finalizing design.
How does it affect parking?
Requirements differ by location and unit type, and some situations may not require replacing lost spaces. Ask the local planning department how your lot is treated.
What drives cost most?
Utility distances, foundation and site work, unit size, finish level and permit fees together shape the budget. Utility trenching and slope work are the items most often underestimated.